| Game | Problem(s) | Fix |
| 1942 | Plane constantly firing | Common fault on these boards (and others of the same family) - one of the LS367s that handle control inputs was fried (position A4). |
| 1943 | Glitchy sprites in certain screen areas | Appears to be due to the +5V pins all being burned to a crisp, turn up 5V line and problem goes away - pins replated (self adhesive copper tracking with a liberal covering of solder) and the problem has gone away. |
| Aero Fighters Ltd Edition | Controls messed up. Left = left+fire, etc. | These are sony PSX hardware gameboards. I put it into self test and noticed that the inputs actually checked out, so it had to be the game code itself breaking. On the main pcb is a set of 4 dip switches. ONE of them is a backup memory clearer. Switch them all on, turn game on, work out which is the PSX hardware test, turn that off, turn it on, off, turn all dips back off, and set the game back up in the test menu - problem resolved. |
| Air Duel (conversion) | Sprites blocks of colour, sound duff | The sound issue was actually due to a known faulty mainboard, as I'd donated the working mainboard from this to a Dragon Breed. The top romboard seemed to have a problem anyway though, and was reading sprites as blocks of colour. I also had a totally knackered Ninja Spirit with a failed security chip and romset. Ninja Spirit mainboard also seemed dead but was actually just too much dirt on the edge connector. Cleaned up and swapped the roms from Air Duel onto it. Board fixed. |
| Air Duel (conversion) | Sound cut out during play, game RAM NG 5 after this | Ram 5 on bootup is the pair of 256k SRAMs near the sound Z80, by the ribbon cables. I replaced these, and the problem remained. It appears that if the ram test fails, then the board won't even try to play sound, the SND interrupt will never start (samples still happen, these are produced by the security chip!). I made various attempts at diagnosing this, but it's a complex beast. Since I knew something between the Z80 and the YM2151 was at fault, I simply replaced every chip that linked them together. This worked :-) |
| AR-3 (Atari System1) | Rumbling from left speaker | This was making a rumbling noise from the left speaker, as if there was a really bad connection somewhere, but the actual sound being played was fine. The noise would continue and fade after the cab was switched off. Replaced TDA 2030 amp chip for left channel, no change. Then I noticed a 224 25V ceramic cap was physically damaged on that channel, replaced to fix. These glass encased ceramics are nearly impossible to source, but a standard ceramic disc capacitor of the correct rating will work fine. |
| Arabian (Atari version) | Player would continually jump | Tracing from pin 7 underside through a resistor pack, I noticed on one section of track, it appeared to be shorted to ground. Further investigation revealed IC13 (74LS368) had internally shorted the up input and ground. Replaced, now working. |
| Aurail | Jailbars on the backgrounds, flashing colours, messed up title screen | The 1mbit 28 pin mask roms can be read as 27C1000s if you build a tiny adapter. take a 32 pin socket, bend pin 30 outwards, and run a wire from pin 32 to that leg. Plug rom into this and any eprom reader should cope with it. Two roms in the tile section verified as bad, replaced with two 27C1000s, fixed. |
| Bad Dudes VS Dragon Ninja (1) | Distorted music | Someone had previously replaced the op-amp. I replaced it with another one, but the fault remained. Next I changed all the electrolytic caps surrounding the op amp, but the problem still remained. Then I replaced the music channel DAC, which proved futile. In a fit of annoyance I shotgunned the rest of the sound section, and the fault came down to a tiny tantalum cap right next to the op-amp... You live and learn. |
| Bad Dudes VS Dragon Ninja (2) | Some graphics flashing corruption (certain frames) | Seems to be EPROM related, but all of them check good in a reader, so it may well be some of the attached buffers instead. Will return to this one when I have time. Checked ROMs again, multiple pass read - #12 showed up as reading inconsistently. Replaced to fix. This fix dedicated to nolanXL, it's one of his favourite games. |
| Bagman (Stern) | Resets endlessly | I lifted the reset pin of the Z80, to see it jam with coloured blocks all over the place. First decision was to check out the ROMs, 6 of them were corrupted - these are slowly being replaced due to my POS programmer. Oh well, it's traded now for a bootleg Moon Patrol since I needed a working set to diagnose the problem another is suffering. |
| Bionic Commando | Background and score/lives display problems - appearing to be drawn twice, halfway up the screen | The small top ROM board was the cause of this, or so I thought. Reseating the ROMs appeared to make the problem go away, only for it to happen again a few minutes later. Actual cause was one of the 3 ribbon cable links between the two main boards - changed them all, problem gone. |
| Black Dragon | Character falling through scenery (scenery being mis-drawn I think) | Seemed like ribbon cables at first, but eventually proved to be a heat related issue on the video board. Took a short cut with this one, I had a sort-of working Black Tiger set with a bootleg CPU board and original video board. Simply swapped the video boards and ROMs around - fixed. |
| Black Tiger (bootleg) | Sparkly trailling sprites, resetting, broken backgrounds | Mostly all caused by poor solder joins, the sprite problem was additionally down to some slow replacement SRAMs on video board. They need to be 15ms. |
| Bomb Jack (bootleg) | Resetting constantly, jailbar backgrounds. | Resetting started after reseating the chips to kill jailbars - turns out one of the ROMs had a very rusty leg which snapped! Jailbar backgrounds was actually a ROM on the top board, which just needed reseating. |
| Bomb Jack (bootleg) | Black screen during boot, eventually booting to partial background, when coined most of title screen missing (character graphics issues) | Checked the character RAM in 6L, most outputs looked very dead. Replaced RAM but problem remained. Started tracing data lines through stalled buffer chips to a 74LS245. \E on this chip was dead stalling all the data lines, traced to a 74LS08 in 8C. Replaced to fix. |
| Boogie Wings | Backgrounds missing | Flexing the board got the backgrounds back. Fault eventually (2 hours) traced to a pin on the custom at 11H, by individually checking every pin join on every surface mount chip. The board has *lots* of those.. |
| Bosconian | Faded colours, bleeding, light bars | This problem affects cabinets that rely on boards to supply VID GND. I simply linked that pin on the JAMMA adapter to one of the common ground pins. |
| Cabal | Jailbars on sprites, flickering sprites | Flickering sprites were down to a cracked solder join on the interface pins for the top ROM board. Jailbars took longer to diagnose, the sprite RAMs are the ones closest to the front edge of the PCB, 2018s. After lots of tracing I noticed one of the resistor packs used on the address lines had a bent pin, touching the one next to it.. |
| Captain America & The Avengers (1) | Sprites all over the screen | Sometimes you see an intact sprite, then it turns into what looks like a sprite tile dump on a different animation frame. On hold until I learn a bit more. |
| Captain America & The Avengers (2) | Dead | Seems to be in a reset loop. |
| Captain America & The Avengers (3) | Corrupt sprites, loud whistle | Corrupt sprites came down to a whole load of lifted legs on the surface mount video chip, middle-left looking from the edge connector. Sound diagnosis started by removing the op-amp which both OKI chips fed, since a strange oscillating voltage could be seen across all inputs/outputs on it. This made the sound stop, replacing the op-amp with a good one returned the tone. Next I lifted each input leg in turn, this showed that while one OKI was making a louder sound, both were doing it. Next I checked the ground for the OKIs, direct trace to common there, so I started to trace the input voltage. I worked back removing filter caps and re-testing, until eventually reaching a voltage regulator with a broken leg. The regulator turns 12v from the edge connector into a 5v feed for the OKI chips. Replacing the regulator fixed the board. Two important notes here: 1) I would have known the input was broken if I'd bothered to scope it before tracing back, saving time. 2) It appears that OKI chips can still function with a missing voltage input! |
| Carrier Airwing (1) | SROLL RAM BAD | CPS1 base boards are not fun to fix, and this is where the scroll ram is. I swapped on a replacement... |
| Carrier Airwing (2) | Dead, missing samples, no sound | Was sold as untested and didn't boot. That was fair enough, until I turned it over and saw the 1 inch gouge across the RAM area. It was deep enough that it nearly went through the other side, and the pressure had indeed broken a few tracks topside as well as literally cutting away ones underneath. It took a bit of tracing, but I managed to get the repair down to 4 jumper wires on the underside of the board. Everything else /seems/ secure so hopefully it will last. Then I noticed the samples were missing, I took the boards apart again and noticed one of the pins in the A/B interconnect near the sound, was bent at a right angle. It caused +5v to go to an address line. Straightened the pin, same problem, and then the music died too. I noticed the music would die as the game warmed up, so I started scoping the address lines on the sound CPU/RAM and YM2151, and saw the waveforms drop to approx 0.5v every time the sound dropped out. I decided to remove the RAM first as it was the most likely suspect (and easiest to replace), this made no difference. Next I decided that since the samples kicked in occasionally, it might be the OKI chip which plays them. Removed this (sadly ruined a track while doing so and have repaired it with part of a resistor leg) and carefully hand soldered the new one in. This took a while - 4 sided SMT chip. It also fixed the game, the +5v had probably caused it to go bad. |
| Cobra Command | Burning smell, yellow screen | Not sure why (I can't find any evidence of bridging) but 2 SRAMS and 2/4 ROMS on the bottom right of the board shorted internally, generating massive heat. It's possible one of them went initially and took the others with it... Replaced dead ROMs, replaced dead RAMs, board still dead, one big 4 sided custom is getting *VERY* hot still, so I've sent this board to the parts stack. |
| Combatribes | Sprites = blocks of colour | Sold to me as working, I think this one suffered in transit. Poking around on the PCB revealed that the symptoms changed when the right hand SMT chip was pressured. Checked all pins, found 8 or 9 broken pin joins on the PCB. This fixed it. |
| Commando (1) | Black screen on boot | Initially I suspected the eproms, as two near the security chip had obviously been replaced (U3/U4). These tested bad in a rom programmer, so I replaced them. Board still dead. Had a quick poke around with a logic probe, and noticed that *everything* was dead - all lines either high or low and unchanging. Went to look at the clock section, and probing with an oscilloscope found the crystal was dead. Replaced this and the game started to run minus the music. Music pot was missing... Replaced this and board is now 100%. This was by the way, yet another PCB sold as tested/working which not only didn't work, but even had missing components. FFS... |
| Commando (2) | No sound, physically cracked top rom, spites missing bitplanes | Rom was obvious - the lid had cracked off - very odd inside. Be careful when removing roms broken like this because the casing splinters. Sound section was quite obviously dead due to a cap hanging out. Replaced this and the sound came back, but sprites still faulty. Sprites problem traced to a deep gouge in the lowest PCB, cutting 4 tracks near the lower ribbon cable socket. Repaired with wire patches, board fine. |
| Cosmo Gang the video | Later levels corrupt, crashes during them | Easy one :-) Someone before I got it had mixed two of the object roms up... |
| Cosmo Gang the video | Coin 1 and other inputs failed. | Near the JAMMA connector, you'll see several rows of resistor packs. The one 'on its own' does coin 1 among other things. The joints on this had been bent back and forth too many times and failed. Shaving away resin with a craft knife revealed enough of the pins again to solder it back down. |
| Cycle Warriors | Jumbled sprites, stuck/crazed inputs, constant sounds | The initial fault was just jumbled sprites. While I was probing around I think I blew a track under the sample roms, but I repaired that with a wire jumper. Board turned out to be an undumped version, nd while I was looking more carefully at the underside, I noticed two touching chip pins. Bent them apart and the sprites all came back. Unfortunately at this point the music died, then the coin insert sound started to play on repeat, and the inputs started strobing. This gets worse the hotter it gets. Eventually the game stopped booting until it was warm, inputs still stuck but no longer pulsing. I was so depressed I sent it to someone else to take a look at - it's probably the Sony I/O chip which connects to all affected items including a dip switch that stops the clock signal. |
| Double Dragon II (1) | Sound effects FAR too loud, echoing, corrupt, playing randomly | I noticed when warmed up there were moments when this problem went away. Theres a surface mounted OKI sound chip on the board, which I suspected to be at fault, but resoldering the pins didnt seem to help. Replaced this and problem remained. Got very annoyed and resoldered all the track top/bottomside links and the solder joints on every component in the sound section - that fixed it. :) |
| Double Dragon II (2) | Sound dead, dollar signs across whole screen, messed up title graphics, corrupted+blocky sprites | Dead sound was a missing capacitor in the amp circuit (without it the board just made a loud hum and optionally picked up radio!). The dollar signs and confused character graphics was down to the LS273 (IC32) next to the character rom. Sprites problem came down to two of the 1 mbit 28 pin mask roms on the underside, IC113 and IC114. These can be replaced with 27C1000 roms (NOT 27C010 type). |
| Dragon Breed (1) | No sound. | Stupidly simple, a broken cap joint. |
| Dragon Breed (2) | Some sounds missing, some sprite colour corruption | The middle board is the problem here (verified by attaching romboards to an Image Fight mainboard). I need to get hold of lots of RAM so I can try fixing this. Update: replaced the suspect RAM, problem didn't go away. This now seems to be the same cause for all problems, and relates to inputs to one of the PALs. Update: I wussed out and replaced the middle board with one from a faulty Air Duel - fixed! |
| Dragon Breed (3) (M81) | Dead, dotted sprites | Before power up many underside crossed pins were straightened out. Next the missing PAL was replaced. M81 boards are very similar to M72, and the M72-8L and M72-9L pals from an M72 board correspond to M81-9L and M81-9P. This brought it to life but the sprites were speckled. Looks like a manufacturing defect was responsible, one ram which looked untouched had one side out of the pcb, just resting on the solder holes. Soldered it in and board was fine. |
| Dragon Breed (3) (M81) | Some wrong colours on sprites | The KNA91H014 at T9 on the top board (this also corresponds with a similarly placed one on M72 sets) appears to be involved with sprite colour output, the analogue part of. The three resistor arrays next to it, when damaged, appear to affect different parts of the colour output. One of mine was badly cracked - replaced and the problem went away. |
| Drift Out '94 | Pink screen and raster corruption, colour imbalance | Being one of the Seta boards with a giant heat sink over a SMT, I knew the graphics would probably be cracked pin joins - seen it before on these boards. Sure enough 5 legs all on the far right corner weren't attached. Reflowed these and the graphics worked, but the screen had a strong pink/red tint, to the point of fringing on some graphics. I had a look at the colour feeds and found an array of transistors, one for each colour and one for sync. Checking with a meter, one of the transistors (green) was showing totally different readings. Replaced all three with brand new ones and the colour balance was restored. Also replaced all the missing 5v filter caps on the ROM board at the same time. |
| E-SWAT | Sound dead (sporadic life) | Sold as having dead sound, under test the sound would occasionally start working for a few minutes. Flexing the board appeared to make so different, but light tapping did. Checked the 8mhz crystal in the area tapped (just to the left of the sound Z80, but does NOT provide clock signal for that chip), and it was stuck high (presumably sometimes working). Swapped this crystal and sound returned. |
| Elevator Action | Coin 1 not working | This proved hard to diagnose as the credit wiring has already been hacked about a bit - I've heard rumour of a modification needed for these boards, maybe that's what it is. Wired coin 1 up to service switch - problem solved. |
| Empire City: 1931 | Parts of some sprites transparent | Using MAME and blanking out rom images, I diagnosed the problem sprites as being in rom 18 or 20. Stupidly without checking I cut these both out and replaced them, which fixed it, but while doing so I noticed several of the pins on 18 were sitting solderless in the PCB, and were probably not making good contact if at all. |
| Fighting Hawk | Sound effects ok, music gone | Identical fix (even same part number) as Plotting(1) below. Seems to be a common fault on these smaller Taito boards. |
| Final Star Force | RAM 3 ERROR | RAM 3 on this board is a pair of 6116 equivalents on the top board, about half way down. I swapped them with new ones and the problem remained. Strangely it didn't complain when no RAM at all was in there, or when just one bank was. While I was starting to probe the address lines, I noticed some physical damage between the two ram sockets. Checking with a meter, sure enough one address line was broken between the sockets, and another worked but looked damaged. I installed wire jumpers between the sockets on those pins, on the underside of the board. All works now. |
| Flying Shark (bootleg) | Burned edge connector | The top side ground pins on the edge connector had burned to a crisp. The lower ones were OK, but did start to get a little warm if the game was left on for 10 minutes or so. I used some copper adhesive strip, and folded it over the edge to cover both sides where the pins run, then stripped a little mask back from the ground area and soldered both sides to the strip. Seems to hold up quite well which was a surprise, and the heat issues are now gone. |
| Flying Shark (1) | Dead | While checking the CPU ram lines, I found a 74LS245 connected to address A7, which if it had a logic probe on it, would cause the game to try to boot (and hang on a sound fault). Replaced the 74LS245 and the problem became worse, now requiring my entire hand bridging most of the pins in that area to get the partial boot. Checking the data pins on the CPU RAM, the traces were noisy and quite unstable. With the probe on one of the affected data lines, I started touching chips to see if anything would cause a response. Touching the sound RAM (a 6116) resulting in lots of trace movement, so I replaced it and a 74LS245 to the right which was causing the same thing. After this, just touching the chips resulted in no trace movement, but the data lines still looked suspect. Touching the data pins on the RAM directly still caused movement, so I used a logic probe on each one, and noticed that address line A1 was floating. I wish I'd checked that before replacing the chips... The sound ROM was also floating on A1, which connects to A1 on the sound Z80. That looked OK, and a quick continuity test showed the track under the CPU must have cracked. Wire jumper repair - game works! |
| Flying Shark (1) | Static interference and humming on boot. | This happened after I made the repair above. The sound section on the board had been worked on before, one mylar cap was missing, and the remaining two had resistors bodged between the leg and ground. I removed the hack and put all 3 caps back in, and the board started to display nothing but a static interference. Removing the caps again, the game booted. Strange. This is the same fault as Flying Shark (2) below. I took a look at a working board, and noticed the sound amp cap had been replaced. Thinking that it might be the cap contaminating ground (which would explain the generally noisy traces I'd seen before), I took it out and tested it - it was only reading 19uf instead of 470. Replaced this with a good cap and the game started booting again. |
| Flying Shark (2) | Static interference and humming on boot, dead 68k, sprite corrption and jailbars | Removed the mylar cap and sound cap, game now comes up with a black screen which is a huge improvement. See fix above for why this works, as it's affected 3 boards now (my worker had already been repaired by someone) I would suggest this is a design flaw on these boards, and a common fault. This board has been worked on a lot in the past, currently the 68k is socketed and totally dead. While checking the connections on the 68k, found one address line with a dry solder joint, fixed this but game still inactive. Wasted loads of time tracing the reset circuit, only to find later that one of the new code ROMs was incorrect. Game started to boot with masses of jailbar and corruption coming from the sprite section. The 2 banks of 3 2148-55 ram had been replaced by a previous owner, pretty sloppy job - found a broken track on one bank of RAM, fixed that but corruption remained and even got worse. Checked out all the data/address lines, then noticed the /WE line on one bank was floating, and stuck low on the other bank. Traced this these through many chips and both ended up on a 74LS08 in E5. Replaced this chip, masses of corruption now gone, corrupt blocks now moving around like the in game sprites should. Testing the two banks of RAM, one is being displayed (corrupt), the other isn't being displayed at all giving a jailbar effect. Need to put a scope on all sprite ROM and RAM now to compare the two banks. |
| Flying Shark (3) | Dead | Another total basket case. Applied cap fix as documented above, still dead. Noticed while probing around that some lines on one of the main buses 'fade' to low, blowing in the top right area of the PCB to cool it down makes them die again - I had to do a LOT of fairly invasive isolation work to track the are down though, even cut a track - 17 chips on these bus lines and any one of them could be faulty. I think I narrowed it down to one of two LS240s in the top corner, replaced them both and the slow fade-up seems to have stopped. Game is still dead though so it was probably unrelated. |
| Forgotten Worlds | Would sometimes freeze during the first 10 minutes then start running again | Obviously heat related, this was either a) dry joints on the graphics engine crystal (music was still running) or b) the dodgy join on one of the interconnects. I'm not sure which, I did them both at the same time and it works now. |
| Forgotten Worlds (2) | Graphical bar corruption, missing tile lines. | I suspected this would be a fault on the LS245s which talk to the game ROMs, and one of them showed an input stuck high. Tracing this to the next component showed that the track was broken due to a small but deep scratch. Jumper wire repair fixed the game. |
| Forgotten Worlds (2) | Similar to the above again! | Turns out part of the problem above was not fixed, as some problems came back. Touching the surface mount ROM legs made all kinds of corruption appear, noticed 4 legs needed reflowing. Problem fixed. |
| Future Spy | Sound effects started to fade away to nothing, some packed up entirely | Zaxxon hardware boards are infamous for this - they rely on cheap capacitor leakage to play sounds.. The missing sounds were caused by IC U23 (D8255) which controls the sound latches packing up. For the fade problem see http://www.system11.org/temp/zaxxon_sound.txt |
| Galaga '88 | Music missing | Sold as working, wasn't. I did get it cheap though and a partial refund, so I guess it was OK. Schematics exist for this which made life very easy - the YM3012 outputs music to the op-amps, I could see a signal going into the TL085 in P5, but nothing coming out of the other side. Replaced chip, all fine now. |
| Gallop (M-72) | Weak sound, samples either playing too fast, not at all, or repeating | Weak sound was down to one of the 2200uf caps near the volume pot, having a corroded leg. The samples issue turned out to be all three LS191 counters that step through the sound data on the sample rom (IC16 -> IC18) on the top romboard. |
| Gals Panic S Extra | Sound getting more distorted as game warms up. | Seen many Supernova motherboards doing this now. The fix applied to S2 below makes the problem go away, but only for a while - looking at ones with the issue that have obviously been previously repaired. I recently got a much newer variant of SN motherboard, Kaneko obviously realised there was a flaw, as the newer ones have an extra 4.7ohm tantalum cap soldered underneath C18 as a helper. Fix now applied to 2 other faulty Nova boards.. |
| Gals Panic S2 | As board warms up, sound gets more and more distorted, particularly right hand channel | After trying the obvious dry joint fixes, this turned out to be the 4.7uf 25V cap that sits on the feed of the thyristor near the sound amp (which in turn powers the op-amp). Extra info, see S Extra entry above! |
| Gemini Wings (bootleg) | Dark fading pulsing picture | Looked exactly like a lack of monitor earth and that's exactly what it was. The bootleg board appears to not have this pin (14 topside) connected to anything at all - small trace wire to a common ground point fixed this. |
| Ghosts n Goblins (1) | No Sound | Well, there might have been some very quiet sound, I didn't hear it. This turned out to be the large axial capacitor near the amp section on top board, which had a broken leg right against the side of the cap. |
| Ghosts n Goblins (2) | Jailbars on all the backgrounds and other tiled graphics | Simple problem - two fried roms (they wouldn't even erase) numbers 6 and 7 on bottom board |
| Ghosts n Goblins (3) | Dead, garbled backgrounds, no sprites, jailbar sprites | Bought untested (expected to be broken) and it was. In fact it got worse after 5 minutes testing too. Firstly the game died completely, no life seen on 74LS04 at 3N next to the crystal. Replaced 74LS04 to get the game going again. NOTE: The timing circuit seems quite sensitive - a brand new 74LS04 wouldn't work, but a much older one salvaged from a parts board worked just fine, as did brand new 7404s. Checked tile ROMs on video board, noticed many of the address lines were stuck and one floating. Traced fault to a dead 74LS273 in 5A, background restored. Checked sprite ROMs next, no activity on CE lines, traced through 74LS139 near memory configuration jumpers to 74LS273 in 8J. No clock signal on 723 traced to faulty 74LS139 in 9K, replaced to get jailbar sprites to appear. Checked RAM at 12N and 7N, both looked normal, started to trace the output lines and found 74LS273 attached to 7N RAM to be mostly dead. Replaced and jailbars gone. |
| Ghouls n Ghosts | Test mode hangs | Game works fine, but set the dips to go into test mode, and it hangs after the RAM/ROM checks finish successfully. I really don't know why this is :/ It's a very low priority fix - maybe it's the PALs, it shares one with Forgotten worlds so I'll try that theory at some point. Sold now. |
| Gladiator | Slight graphical corruption | EPROM QB0-12 had physically caved in - oh dear. Replaced this and took the time to clean off all other socketed chip legs and problem is resolved. |
| Golden Axe | Nothingness, all filter caps broken off | Unbelievably this worked fine as soon as I cleaned the edge connector!! Replaced filter caps anyway, board fine - what an easy fix :-) |
| Great 1000 Mile Rally | Sound sort of weak and crunchy | Fixed after replacing the sound section caps, half of which were missing due to physical damage. |
| Green Beret | Broken graphics, sound stuck on and corrupt | Graphics easily fixed with replacing one of the roms that had failed, and reseating the CPU. Sound problem was a sticking 74LS253 in 5B. |
| Growl | Sound broken up, sounds playing at the wrong times. | While looking up which ROMs held all the samples, I found out which chip did all the sound I/O - surface mount custom TC0530SYC. Checked all the pins, found one lifted - reflowed to fix. |
| Gryzor | P1 fire dead, P1 jump constantly held down | A common fault on Konami boards of this age is failure of the 74LS253s they use to encode the inputs. P1 fire and jump are both handled by the 253 in position 3E, probed this and confirmed failure - replaced to fix. |
| Gun Frontier | Lots of audio noise, initial intermittent freezing, eventual death. | Audio was something I've seen on a lot of Taito boards recently - the 12v filter caps were shot. The freezing error is something this board has always had, I always suspected something wasn't seated right or an SMT pin was cracked, but I could never find the fault. Recently I took it out of storage and lent it at an angle on something for a few hours - came back to use it, dead. Checking around, I did indeed find that one of the SMT legs had a cracked join, reflowed it and the game is running perfectly now. |
| Gunforce | No Sprites | Jumper J3 on M92 boardsets is involved in the sprites somehow, I'm not entirely sure what it does but having seen this same problem twice now I can tell you what will happen if it's missing - no sprites. Position may vary by game, but every game I've seen has it jumped for 'B'. |
| Hammerin Harry | Corrupt flickering background layers, every second quarter of the screen | I thought this might be a ram fault, but the board self test claimed the ram was OK. Piggybacking the background RAM on the lower board made a improvement though on the one in 8D. Replaced suspect chip and all is well. |
| Heated Barrel | Flickering messed up sprites | A nice easyish fix - there was a pretty vicious scrape on the back of the board that broke 4 tracks near the sprite RAM/ROM - only hard bit was repairing the damage since the tracks are so fine. |
| Hotdog Storm | Flashing and stuck in test mode | This may well be a lost cause. The board is flashing and repeatedly going into test mode - but this seems unrelated to any inputs. In addition, this had soldered roms, and someone has desoldered them all and socketed them into place - badly. Update: one of the LS273s in the top left of the board "influenced" the problem when touched, so I replaced it. Hasn't helped, I think this one is dead, now a parts board. |
| Hyper Sports | Two vertical rows of character graphics appear to be missing a bitplane | I think this is probably a RAM fault - currently studying the schematics to try and make some sense of which RAM it might be. May shotgun it. ROM c11 also diagnosed as failed after noticing corruption on the weightlifter graphic. UPDATE: Replaced c11, weightlifter ok now. I think the other fault must lie in the character ram section. UPDATE: It appears the attribute ram which maintains a table of colour values and character locations is somehow at fault. This is the pair of 2048 RAMs on the middle of the video board. Board no longer owned. |
| Ikari Warriors (1) | Sound cutting out, sprites flickering horribly or vanishing entirely | Sound was bad seating on two yamaha chips. Sprites fixed by renewing faulty board link cable. |
| Ikari Warriors (2) | alternate lines of sprites missing just for some colours | This has been diagnosed as being one of the 2018s on the middle board. Planning to replace ram and see what happens. UPDATE: replaced rams, no change, put this one in the parts pile. |
| Iron Horse | Totally corrupt graphics, game running. Controls wrong. | Simple case of the Konami custom CPU needing reseating. These are a very tight fit so be careful when levering them from the socket. The controls being wrong (buttons 1 and 3 linked) was down to someone wire-hacking it into being a 2 button game. Oh dear. |
| Juno First (1) | Tripping power supply, graphics | A quick continuity test showed that 12V was shorted to ground. This turned out to be one of the 1000uf 25V caps on the 12v rail near the amp. This repaired, the board came up but exhibited a line of 'sticky' pixels on the screen. Cleaned all pins on the 3 Konami customs at the back of the lower board, problem went away. |
| Juno First (2) | Sound effects truncated or missing | I suspected a RAM or ROM fault, but the ROM's checked out. One 2114 RAM had failed before, but it made no difference when removed, and no difference when replaced with a known good. Bridging the other 2114 with a known good brought the sounds back to life, so it was replaced. |
| Kangaroo | Inputs (various) not working | Cleaned edge connector with isopropanol - works fine now :) |
| Klax (bootleg) | Freezing, bleeding+dark colors | Freezing caused by a substandard previous repair - reworked that and it seems ok now. Colour problems were simply down to the bootleg having no video ground line - added a wire from common ground to pin 14 on the edge connector, fixed. |
| Knights Of The Round | Dead on boot, few static graphics | Game had suicided - performed the fixes detailed on the Dead Battery Society pages and the game worked perfectly. |
| Knights Of The Round (2) | Dead on boot as above, corrupt sprites | After desuiciding the game, corruption was seen on certain sprites, which came down to one of the graphics ROMs. On this board the replacement part is 27C200, non JEDEC chip. |
| Kung Fu Master | Buzzing from speaker | Waiting for an oscilloscope to try and trace this, changing all sound section caps(!) in the meantime. Done all the electrolytic and this only slightly improved - will do the big high voltage resin dipped one next, and the tantalum. UPDATE I never got around to fixing this fully, although I did reduce it an awful lot through extensive recapping. It's sold now. |
| Last Mission | Not even getting to self test, nasty grungy crackling from speaker | On Last Mission boards there should be a trace wire or two running underneath the PCB. The longer wire running to the ribbon interconnect solder joins had broken off. Careful examination of joins hilighted which one it had come loose from. Sound after investigation turned out to only crackle when turned up. Suspected amp chip, but noticed large 470uf 35V cap was missing (completely) - which is used by the amp chip on many Data East boards of the time. |
| Life Force | Resetting constantly, black screen | Quick boardswap diagnosis showed this to be a faulty video board - possibly a broken custom. Quick fix for this was to swap in the working video board from Salamander (3). |
| Major Title | Sound would cut out as if the CPU had crashed | Ridiculously easy - PAL needed the legs cleaning up a bit. |
| Major Title (2) | Sound popping loudly, worse if volume turned up. | C203 470uf/25v cap on the 12v looked solid, but tested bad on the ESD meter (no reading at all), and the leg fell off while it was being removed - replaced to fix. |
| Mikie | Sprites vanishing dependent on location, bits of sprite logo missing | Looking at the schematics, I checked the area of the board that appeared to deal with sprite handling. The 74LS163A in position A11 on bottom board which is used for sprite selection, had a failed output. Additional note, undocumented (wire) jumper JP7 S0 is a screen flip for this game! |
| Mikie (2) | No sprites, jailbar effect on some tile colours | First I tried replacing the sprite ram which is 2x 2148s. This made no difference. Next I started tracing from the ROMs, and found address line A1 was floating. Replaced 74LS86 in D5 which brought the line back up, but now it showed as stuck. Checked the inputs for D5 and found the 74LS273 in D6 which feeds them was also floating. Replaced - 4 fine lines of sparklies now more obvious than before, and address A1 pulsing correctly. On a hunch checked the 74LS86 above the failed one in D5, and found a dead input, traced this back to a 74LS174 in A9. Replaced this and sprites now visible, although corrupted in places including the logo. Started checking the rom address lines again and found address A13 stuck high. Traced this to a faulty 74LS174 in C4. Sprites now correctly arranged, but some parts are transparent. Unfortunately at this point the sprites failed again after 5-10 minutes. I started checking each chip in turn and found a 74LS139 decoder in A7 with a stuck output, seems to be connected to a counter array that generates addresses? Replaced that and the semi transparent sprites were back. I decided since the RAM and ROM address lines were OK, but it looked like a bitplane was missing, that it would be worth tracing the data lines to see where they went. Eventually fault traced to a 74LS175 in F10 which is part of the data line chain between the ROM and RAM. Jailbar effect on some tile colours was a poorly seated tile ROM. |
| Mikie (3) | Constant hum with corrupted screen and semi-broken sync, incorrect colours on some sprite frames. | I started by trying to diagnose the sync problem. This proved quite tricky but eventually following the sync line and all the chips involved in generating it, I found a 74LS161 in B3 with a stuck output - replacing this gave a frozen game still but the picture was rapidly rolling instead of being skewed and wobbling half way up. More checking located a 74LS04 in C1 which is connected to both LS161s that do the sync and vertical positioning, which had stuck on all lines. Replaced that and I had a stable image and no more noise. The game was running at this point, but the graphics were just horizontal lines (vertical essentially, remember this game is on its side), which moved around as the graphics might have been doing. I decided it looked a bit like column 1 of the display was just being copied all the way across the screen, and started looking for things that might control positioning. Checking all the V lines across various chips, I found that several of the ones on the 73LS377 in C8 were doing nothing although I could see pulses on the inputs. I piggybacked a working LS377 but the outputs on that matched the ones on the suspect chip. Checking again and comparing to a known good board, I noticed the pulses on the inputs were different, and scoping them something was obviously wrong. The outputs for the V lines come from a 74LS373 in A8, since piggybacking this with a known good got the signals I wanted to see, I replaced it. Game now visible! Noticed on a playtest that the player sprite was an unusual colour set, and would change colour depending on animation. This turned out to be 1 sprite rom from the Japanese set being on the board. All fixed! |
| Missing In Action | Reset on boot with ram error | The 2018 SRAM in C19 was being reported as bad on boot. Replaced, problem resolved. |
| Moon Patrol (1) | No sound. | The amp was missing... I'm waiting for a replacement part. UPDATE - amp arrived, fitted with a heatsink borrowed from Major Title, board now 100%. |
| Moon Patrol (2) | No sound, repeated backgrounds | Sound was due to bad seating of chips. The video problem looked exactly like the one exhibited in Moon Patrol (bootleg) below, but all the horizontal counter lines were fine. Further inspection of scrolling video board showed a broken track. Repaired this and all is well. |
| Moon Patrol (3) | Music hilariously out of tune | Now seen this twice, sometimes when the big AY sound chips on the top board go bad, sound will be intermittent, or out of tune/cut off/all of the above. Replace to fix. |
| Moon Patrol (4) | Sprites not moving | Another easy fix - bad ribbon cables! Probably causing a clock signal to go astray. |
| Moon Patrol (bootleg) | Repeating backgrounds | Odd effect, sprites still ran correctly but background repeated several times horizontally. Turned out to be oddly labelled FPU unit on scrolling video board, position 7H. Filing the pins lightly and reseating fixed this. Update: or not.. Now back here awaiting a working set to compare it with. Freeze spray has failed to identify the problem which is now constant. Update: got another set today, used combinations of boards to narrow the fault down to the main board. Checked horizontal counter section on the schematics, and fault traced to one of the two 74LS86s that the counter output is passed through. Fixed! |
| Moon Patrol (bootleg) | Amusingly out of tune music | On the sound board are 2 AY3-4910 chips. The one closest to the amp appears to do the music generation, and it was being very unreliable on bass tones. Swapped it, problem fixed. |
| Mr Heli | Tempramental sound, worked sometimes and not others | It turns out that a capacitor is used to delay the reset of the sound Z80 at boot. If the data has not yet copied in before the reset line is pulled low (which will trigger the reset), the CPU can end up booting with incomplete code, and crash. A bad cap here will cause unreliable sound CPU code loading, and the cap in question is the one next to the V30 cpu on the main M72 board. |
| Nemesis | Booting with bad ram reports on OBJ RAM and SCROLL RAM | Replaced what I thought was the object ram, and one other identified RAM on the underside board, but problem remains - although the test screen no longer flickers, so I've fixed something.. UPDATE replaced some more suspect RAM, but possibly with the wrong speed. It's even less happy now. On a lighter note, I now have a Salamander, and I've verified that the top board of Nemesis is mostly alive, although with some input problems (some work, some don't - probably an easy fix). On hold till I can find some known good correct speed RAM (2128-15s). UPDATE: I wussed out and bought a working Salamander, and donated the graphics board from it. The control input failure on the top board was diagnosed as one of the LS253s near the diode array in 3E (affected P1/2 L/R and coin 1/2). |
| Night Slashers | Sparkly dots on backgrounds, incomplete + quiet music | Sparkly dots were down to some very poorly removed and socketed graphics roms - some solder holes were entirely empty. Incomplete sound due to the mono/stereo jumper being missing. However, when the missing channels came back they were very quiet. NS uses 2x OKI chips to generate the sampled parts of the music and the sound effects, one of these had been replaced but it was the sample chip, no problem there. The rest of the music is generated by a YM2151 and YM3012 DAC. The YM3012 is stereo, and while tracing both channels, one vanished on a through-PCB hole. Wire jumper between the capacitor and resistor the track went between restored the audio fully. |
| Oriental Legend 2 | Battery test fails - boots only occasionally | Not sure why a battery test should make these not boot, they only store scores and time anyway. If you have a PGM2 cart that does this, you need to open the cart up and replace the coin cell (2032 I think). I found it still complained until I set the date and time again, and had to power cycle it a few times working this out. |
| Oscar | Wouldn't boot - black screen | This was sent to me working, but on test was completely dead. I sent it back initially but re-aquired the board recently (some months on). It's amazing what you can learn in such a small time ;-) Checked out the timing circuit (12mhz crystal, 2 resistors, 7404 inverter) - no activity. Replaced the crystal and the board came partially back to life, but with no sound or sprites. Determined that the new crystal was only oscillating on one leg, so decided to replace the 7404, resistors, and crystal (again) in one go, in case one component was causing the other to fault. Board now working. |
| P-47 | Stuck in test mode, buttons appearing to be held down | Megasys (P-47, Rod-Land, Saint Dragon, many others) can be sent into test by holding down P1 and P2 coin switches on boot. This is now fixed, please see Saint Dragon (1) fix... |
| Pac-Land | Screen of garbage, no boot, wrong colours, flipped character graphics, corrupt sprites, no sound, sprites jump back/forth when moving. | I started by checking some of the main RAM address lines, A8 was floating, this was traced to a broken track near 10J. Corruption pattern changed slightly. Decided to try replacing the HD68A09 in 8A, game booted to a corrupt, miscoloured title screen. Colours seemed to be lacking all red, replaced colour PROM in 2T to get all colours back. Next I decided to check the backround ROMs, found another dead address line on pin 3 of the ROM in 7T. Traced back to faulty LS174 in 7R - replaced and backgrounds still incorrectly drawn but now stable. This left me with corrupt flickering sprites, and the whole screen was upside down, character line by character line. Checked bank of ROMs starting 8J next, found stuck line A13. Traced to bad LS174 in 6K, and in turn from pin of that to a failed LS139 in 10B, not sure what this fixed.. Checked sprite ROMs next, found dead address line on pin 6 of the set at 6/7/E/F, traced back to faulty LS86 in 9C. This removed the rest of the corruption and also fixed the mirrored character issue (9C is a quad some of the FLIP lines run through). Sound problem was easier, the large filter cap was missing entirely and the amp didn't even hum - replaced both to fix sound. Final graphics issue with sprite horizontal positioning was a broken data track somewhere between the 74LS245 in 8P and the custom in 2R, which is part of an 8 bit positioning bus. |
| Pang | Dead | Another suicided one - dead easy to fix! |
| Phoenix (bootleg) | Sparkly sprites, no music, no screen flip | Sparkly sprites was just down to RAM seating in sockets. No music was the tone generator having failed, replaced MN6221 to fix. Screen flip traced back as far as a broken 7416 inverter, but on further inspection that output is being held low even when working due to some strange repair work which includes a wired in chip. I need to compare this to schematics and try to restore the board properly. |
| Pinball Action | Dead, repeating sound | Disconnected the 12v feed for the moment since it's resetting and the amp is getting very very hot indeed. It has been suggested I should check the caps. |
| Pit Fighter | Didn't boot, blank screen | Poking around and flexing the board lightly showed this to be a flex related issue. After careful inspection, one of the resistors used to turn crystal output into logic high/low had *no* solder on one leg. None at all, looks like it had always been like that from new too. Soldered leg in, board fixed. Amusingly looks like someone tried all sorts of resolder jobs on it and never found the problem. |
| Plotting (1) | Sound effects loud, music faint and crackly | Still working on this, replaced all the caps with no results, and I suspect it's the dual op-amp (C4556C) or DAC (Y3014B) at fault. Bought an oscilloscope, after a tough new learning experience I've narrowed the fault down to the C4556C, it's dead on the A outputs I think (or at least very ill). UPDATE - replaced 4556. After a briefly exciting pyre of smoke coming from the big amp filter cap (my fault, mixed polarity) this board is now fixed :-) |
| Plotting (2) | No video sync | PAL has gone. It's shorted sync output to ground, which isn't a good thing, I need to get a new one made, if possible. Now used as parts. |
| Popeye (1) | Nothing (no roms) | This one arrived with no ROMs, sold to me as a Donkey Kong Jnr (thanks guys...). I made a full romset for it, and an image appeared, but it was just gibberish. Two Popeye sets exist, if this happens to you, reburn the 4 code roms from top PCB with the unencrypted set. Game seemed to work (though without sound and with inverted video since it's a Nintendo PCB) but then died again after 20 minutes, causing 2 large bars of background graphics to vanish. Diagnosed this as a faulty 2016 RAM on the video board, replaced with a 2128 (also 2k x 8 format) and this seems to be fine. |
| Popeye (2) | Screen full of garbage | Checked the code ROMs first, 7E wouldn't realibly read at all - replaced and the game booted. |
| POW (1) | Another with poor sound | Again this was solder joint problems on big caps - seems lots of people out there aren't very careful with boards... |
| POW (2) | No sound at all | Nice easy fix - after a quick poke around I found that the amp legs were corroded and a couple had all but snapped. New amp chip fixed this. |
| Power Drift | Some frames of animation missing | Checking the roms, it seems that the CPU 3 code ones are slightly corrupt - I expect replacing these will fix it, haven't had time yet. Update: sold the machine, replaced the rom before it was taken away, problem resolved. |
| Power Spikes | Intermittent total failure | Lightly flexing the board proved to fix or aggravate the problem, so I decided to first check for chips with suspect solder joints. As luck would have it - a very light twist on the RAM in position 121 seemed to be the key. Resoldered the joints on this, problem solved. |
| Psycho Solier | Game running, but no backgrounds at all | First I checked the tile ROMs (bottom board, P13-P16), but they looked ok. Next I tried reseating all the PALs. No effect. Next I took a look at the clock circuits - fine. Next was the EPROM chip select (OE/CE) lines - they were all stuck high (off). Traced this to the 74LS139 in B5, sure enough this wasn't trying to select chips. However, the enable line on that was also stuck high (off). Tracing this back through a series of LS273 inverters finally led to one which had a floating output (but pulsing input). Chip replaced, backgrounds working! Fucking good thing too as that board cost me a bloody fortune untested ;-) Update Of course 10 minutes later it failed again during soak test. Two of the other LS273s that talk to the tile roms developed problems, so I got annoyed and replaced both of them, plus the 4th one. All problems now resolved. I suspect the initial faulty one got "zapped" at some point before I got it, and the others suffered residual damage. |
| R-Shark | Flickery corrupted/misplaced sprites | This was some kind of board flex issue - pressing in certain areas of the board would clear the problem up while running. After a LOT of time with a multimeter this was traced to a track link where one connects from topside to bottomside, in the sprite hardware area of the board (left hand side if connector is facing you). |
| R-Type | ROM NG on boot | Previously this had been a working board, but one day it came up with that message. All the roms read as ok in a reader, and the two TTL chips on the romboard also looked ok. The mainboard and baseboar dverified ok with a romboard and roms from an Air Duel, so tracks were suspected. These also drew up a blank, so I bought a working R-Type and tested the romboard on the problem boardset. Game ran fine. Individual swapping of roms eventually traced the issue to a romchip with a jammed CS line! |
| R-Type (2) | Blocky corrupt sprites, blocky backgrounds. | I got this and a dead Hero Tomna at the same time. This was reporting RAM NG 4 so I put the Tomna board on and the backgrounds turned blocky.. That was traced to a bad ribbon cable, leaving just the sprites. I established that the top board was at fault by putting it on a known working set, and checked the ROMs. One was bad, looking at it the window was cracked too. Replaced, fixed. |
| Raiden | Flickering sprites, garbled background tiles, corrupt character graphics and logos, no sound, freezing | Oh dear, this was in a sorry state. First I fixed the sprites, this was down to the pin connectors on the daughterboard having fractured joints. Next, the background tile problems came down to a damaged track under the tile roms. The lack of sound was traced to the nasty resin covered custom op-amp effort between DAC and main amp. Luckily Dead Angle uses the same one, so I welded the new one on (nasty job). The corrupt characters (letter M for example) and logos came down to a both the character roms being faulty. Freezing was resolved by replacing corrupt code rom #4 and reseating the main CPUs (lots of times). |
| Rainbow Islands | Game running but no gfx | Having ruled out the custom colour pack as a source of problems, I designated this board unrepairably fucked and sold it on for parts - was probably one of the nasty Taito custom chips |
| Rally Bike | Certain sprites (not image related, but sprite used) missing blocks of 8 lines | Visual inspection found several tracks with the mask scraped off, one of which was broken (bottom right, near sprite ram). Wire fixed this and it's fixed now. |
| Rastan (1) | Inputs glitchy, have to hold down buttons for others to work | If you trace the input lines of these boards, you'll find a collection of LS251s. One of these had failed and been replaced previously, but the repairer had managed to break the grounding pad on it, leaving the chip groundless. Wire-patched the leg to ground, controls fine. |
| Rastan (2) | White screen | Another pointlessly easy fix - this just had a missing rom.. On replacement it worked but the sound was very weak - this was traced to capacitor C23 also not being there. The filter caps were all missing too, and the H connector shorting jumper. Don't these people ever take care of their boards?? |
| Rastan (3) | No sound, rising hum on startup which cuts out. | Checked the YM chips and found that the music is definitely playing. Next checked all the caps with an ESR meter but no luck. Op-amps looked OK but the sound seemed to vanish just before the volume pot. At this point I accidentally shorted the pins on the final output stage of the op-amp section (IC106 pins 5-7), which tripped the power supply - after that the rising hum was gone although everything else remained the same, with VERY faint sound at maximum volume. Explored a bit more and eventually decided it had to be IC106 at fault since no amped sound could be seen on the output anymore, previously there was a tiny amount of trace movement but obviously that section of the op-amp had already partially failed. The chip is a TL074, I only had TL084s (turns out these are a lower grading of the same component), and this restored all sound. TL084 are noisier than TL074, will replace with the correct part as soon as I get one. NOTE - schematics are available for this game! These helped diagnose the op-amp section no end. |
| Rastan (4) | Very quiet sound, corrupt character graphics | Graphics issue was a failed ROM in the character bank, I had a full set on a scrap board so this was a nice quick test. As with Rastan (3), IC106 (TL074)had failed. Replaced with a TL084 and the sound came back, but with a horrible loud whistle. Found that this whistle got much worse when the other TL074 was touched. Replaced second TL074 with a TL084, whistle gone, all OK. |
| Rastan (4) | Sound corrupted and died during play, game froze. | Testing showed that the game would run but crash frequently, if the board was left off long enough the sound would work for 10-20 seconds and the problem would return. Used a lot of freeze spray hunting this down, turned out to be the Toshiba sound RAM at IC50 crashing the CPU. Not sure how this can freeze the whole game, but it can. |
| Renegade | Graphics corrupt, flickering | First I cleaned the masses of solder off the edge connector (I still can't see why this was done, they just made the pins MUCH thicker - too thick in fact). This didn't fix it, but did at least mean the loom could fit properly. The actual problem was bad seating on the ribbon cable interconnects :-) |
| Ring King | Missing sprites | Another board without its full complement of ROMs. I replaced the missing ones, fiddled with voltage, and decided it wasn't worth investigating further after managing to only generate some static floating bits of people. Parted. |
| Road Fighter | Corrupted display, and odd wired-on hack | FIxing the display was pretty easy - just reseated the ribbon cable links between top/bottom board. The hack was strange, someone cut the video sync track and passed the sync through an inverter piggybacked onto another chip. I suspect this was done to run it in a strange or VERY old cab, removed the hack and repaired the track. |
| Rod-Land | Boots with blocks of colour and hangs | Well the bottom board on this is fucked. Looks to have been stored in water, but the ROM daughterboard appears to be fine having tested it on another Jaleco mainboard (from Saint Dragon, P-47 would also do). I need to get a spare mainboard.. UPDATE - see Saint Dragon (1) report, Rodland now has a base and is 100% |
| Rygar (bootleg) | Some colours turn transparent every other frame | Can't solve this one yet - in demo mode everything looks fine. Play the game and some graphics shimmer in places by turning transparent every other 60th of a second. Used for parts. |
| Saint Dragon (1) | Player 1 button 1 dead | Stupid Jaleco megasys boards use utterly fucking uselessly fragile tiny little daughtercards on all the input lines. The pins on these break constantly - this was one of those occasions. |
| Saint Dragon (1) | Corrupt music and graphics | Running a test revealed "ROM ERROR". Since I've donated the baseboard to Rodland now this will have to wait until I've got a rom reader and a replacement base. On a lighter note, the ex-Rodland base is now partially working with minor screen confusion to solve. This has now been designated an unsaveable parts board, as the corrupt roms are custom ones with PALs that have not been dumped. |
| Saint Dragon (2) | No Sound | This was 'something' on the base board at fault - so I replaced it with one from a Takeda Shingen. |
| Saint Dragon (2) | Some sound effects missing | I'm getting really fed up with the shoddy build quality of these megasys boards - as soon as you fix one problem another develops, fucking ridiculous. This time half the samples have vanished and it appears to be top rom board related - but is not the roms. Probably one of those poxy OKI chips I've had so many problems with. Planning to try putting extra eprom sockets onto the Takeda Shingen romboard and populate that to sidestep the issue for now - certainly I can't fix it easily. Takeda just lost its romboard... Thankfully it uses the same security chip as Saint Dragon, and the game is now running fine again. |
| Saint Dragon (3) | Corrupt sprites and backgrounds | Checking the roms, this came down to roms 12, 14, and 17 for the background. Strangely the sprite roms all read ok, but testing with some known good replacements, rom 21 was shown to not work in the board - someone has suggested this means it had a faulty output enable (OE) line. |
| Saint Dragon (4) | Control inputs dead | I expected this to be the resin covered customs along the edge, and indeed it turned out to be controls handled by the middle of the three. Checking the pins on it which are prone to snapping, the 5v pin had snapped, as had the ones for P1 up/right/fire1/fire2. Fixed these with solder bridges but P1 down/left were still broken. Checked the inputs and they looked fine. The outputs connect to a 74LS245 bus transciever. Since other outputs for controls that worked connected to the same pins as the faulty ones, the LS245 I decided was OK. This meant the fault must be the custom, so I replaced it with one from a faulty Takeda Shingen motherboard. All controls restored. |
| Salamander (1) | Booting with corrupt screen | Please see the Nemesis report above - this has a known faulty graphics board with RAM problems and is on hold till I get that far down the priority list ;-) Now also has a faulty top board (2 x LS253s) see Salamander (2). No longer owned. |
| Salamander (2) | Coin inputs dead, p2 fire dead, p1/2 bomb dead (all stuck on) | Quick and easy diagnosis, this was the LS253s in 4D and 4F. I was feeling lazy so simply swapped the working one from Salamander (1) on. Fixed. |
| Salamander (3) | Resetting constantly, light blue flashing screen | This has a faulty top and bottom board now, see Life Force. No longer owned. |
| Salamander (4) | Stuck 1/2 coin, various fire buttons | After much diagnosis and replacement of other parts, this turned out to be a fault in two of the octos that sit beteen the edge connector and the LS253s (that are usually the problem). Identifiable by voltages being out of spec on the affected control lines. |
| Saturn | Failure to boot, corrupt blocks of graphic | Roms 5 and 6 on Saturn boards are on a tidy riser board which plugs into socket 5. The riser board had several broken tracks and ones that tested ok sometimes but not others. I wire linked a bypass on the tempramental/broken ones, and it works now. |
| Scramble (1) | Boots with corrupt screen and appears to hang, but stars work | Well something is working... To get as far as screens able to tell you something is wrong, logically you need a working Z80 (verified), some working ROMs (verified), some working RAM (not verified), and approximately 4 chips (2 critical) which ferry the data between them. Waiting on some known good RAM. No longer owned. |
| Scramble (2) | No sound | First off, the amp was cracked in half. Replaced this but still no sound. Analysis of the sound section showed it was doing nothing - this initially turned out to be the CPU. Replaced Z80, and activity was seen across roms/rams/AY synth chips, but nothing was coming out. I'd already tested the rams by switching them for two new ones, but it appears one of the new must have been faulty - changing the rams again solved the problem. |
| Scramble (3) | No sound | Again as with Scramble (2) the amp was cracked in half, so I replaced it. This board had a missing Z80 and both AY synths, replaced these and still no sound, although there was now activity. Replaced the rams since the in-situ ones looked a bit old and corroded, no change. The new rams did at least give me a good enough pin contact on a logic probe to find the chip select pins were both high constantly. Traced this back to a MS53204 - labelled as '04' on the schematics, and you can use a 7404 or even a 74LS04 here without problems. Sound now working, but some parts go very quiet and crackle depending on which AY output channel is making them - which would seem to indicate some kind of op-amp failure. Replaced all op-amps, works fine. |
| Scramble (bootleg) | Boots to cross hatch and resets/hangs | Verified all ROMs were correct, checked address/etc lines and while some looked a little dirty essentially everything was working. Since I still don't have a Z80 Fluke pod, I started piggybacking the main SRAM chips, the one in 1K caused the game to crash and reset when piggybacked, so I replaced it - game started working. Note: I had two replacement 2114s which I thought were both good, but only one works in this board, it's likely something else is slightly wrong somewhere, which only manifests itself on RAM that isn't outputting a strong enough signal - maybe CPU socket is the real culprit. |
| Shadow Dancer | Very dark washed out picture | Expected this to be a sync problem or a missing video ground, but in the end it wasn't. Checking all the drive transistors, they were reading very high, I still don't understand why that was the case - the actual problem was one of the two 74HC4066 analogue switches - perhaps it was leaking onto the inputs. Initially I thought it was the one closest to the PCB edge since touching the pins changed the screen problems, but actually it was the other one. Replaced both anyway, picture is perfect now. |
| Shadow Warriors (1) | Tile graphics mostly missing and/or corrupted | Sold as working 100% on ebay. Turned out to be a faulty rom on the romboard, took the one from (2) below, fixed. |
| Shadow Warriors (1) | Scenery sprites missing | Initially seen and assumed to be the problem above, this happened again, but flexing the board made them appear. Reflowed solder on the mini romboard, to no effect (shame, it was very tidy before). Noticed while flexing the board that they'd sort of appear again. Checked surface mount chip legs after a feeler test, 4th one down had a cracked solder join on one leg. |
| Shadow Warriors (1) | Most graphics and all text missing, replaced with empty character graphic blocks, only overlaid graphics visible. | ROM 5 on the video board appears to be a character ROM. The socket had corroded (strange as the rest of the board is clean), replaced socket and cleaned up the chip legs. |
| Shadow Warriors (2) | Sparkly jailbars | After buying (1) above, I pulled this out of my board rack - it used to work fine. Now has faulty mini romboard, sparkly jailbars are suspected to be character graphics for the text overlay - as it affects backgrounds and sprites equally - probably RAM. Gave to someone else to try fixing. |
| Shadow Warriors (3) | Sound dropping, occasional flashes of graphical corruption. | Sound was a bad volume pot, what a surprise. Graphics were either the extra romboard pins, or pins on various socketed RAM chips on the video board. These were all filthy so I cleaned them all up with very fine wet & dry paper and everything is fine now. |
| Shao-Lin's Road | RAM1 ERROR | RAM1 is the pair of TMM2009-A SRAMs near the middle of the board, probing one showed the data lines were extremely weak/dead. Replaced this to fix. |
| Shinobi | No sound, some corrupt sprites | I think this one has suicided, it's a later Shinobi that has a suicide Z40 on the sound. I'm getting an unencrypted sound rom made and the suspect graphics roms. Fixed graphics problems, removed suicide battery chip and put in decrypted rom - still no sound. Then, the board died entirely. Fuck. Parted. Update Got a spare E-SWAT board, so swapped the romboard from Shinobi onto it. Sure enough the game ran again with no sound, but I *had* applied the desuicide trick. That was when I noticed two other sound eproms were simply not there... ;-) |
| Shinobi (System 16A bootleg) | Some pixels of lines lagging on sprites | Rom 17 was bad, pretty easy fix really. |
| Shoot Out | Did nothing (no roms) | This came to me as an "untested" which appeared to mean "has no eproms at all". I burned a complete set and luckily it works! |
| Side Arms (1) | Alternate lines of sprites missing | Still working on this.. Initially I suspected ROMs but the alternate lines were alternate lines of the full sprite field, not each sprite. Problem appears to be the Line Buffer 2 circuit on bottom board - accesses to the TMM2014 in that circuit are far fewer than on buffer 1. Replaced the 2014, this hasn't helped. I've ordered full new components for this circuit, and will simply swap them out one at a time to try and resolve the problem. UPDATE: I bought a cheap Side Arms board which turned out to have a battered (and slightly sick) top board, so donated it's bottom board to create one totally dead set (parts) and one fully working. |
| Side Arms (bootleg) | Half the music channels missing / VERY quiet. | Amusingly, ALL Side Arms bootlegs have this fault. Your board isn't faulty, it's just wrong. If you look at the schematics for Side Arms, they show two resistors coming in on pins 5 and 7 of the 16 pin op amp. The one on pin 5 is not implemented on real boards, but the bootleggers did. End result? A severe drop in power on one DAC output. Whoops. Snip this resistor off and your sound will be fine. |
| Silkworm (1) | Specific sprites flickering after warmup | After trying all the various reseating tricks, I noticed that when warmed up, putting pressure on the tiny daughtercard on the lower board made the problem go away. I suspected a dry joint and basically reflowed every joint on the board riser. Still not fixed. Further examination putting pressure on chips with fingers located the problem as being the LS138 in E3 on the daughtercard. Unfortunately two of the solder pads came off the chip socket on the PCB, and the tracks they broke from had to be wire bridged, but it's ok now (finally). |
| Silkworm (2) | Crackly sound | I suspected caps or op-amps, but started tracing from the DAC. DAC output was clean. Op-amp output was clean. Amp output was clean! Poking around a bit with the probe I found that pin 4 of the YM3014B DAC generates a pop when touched with the probe. Closer examination showed the pins feeding this, on the YM sound chip, had no solder on them. Another fault since manufacture, fixed. |
| Silkworm (3) | Dead, sprite colour problems | The being dead thing was down to the resin daughtercard which had snapped off. Repaired this (tricky but possible) and the game booted and ran. Some sprites flicker different colours. Sprite ROMs are fine. Used a process of elimination by removing the socketed RAM to identify which was for sprites. Sprite RAM on this board family is a huge bank of 20x 4164s. I checked all the data output pins and found one of the 4164s had no output, despite all other signals looking good. Two other 4164s had no output, but also no input and strange looking signals, I suspect they're just not needed on this game. NOTE: You need the game running or several 4164s will be idle. Desoldered the definitely suspect 4164, put a socket in and refitted the chip with the data out leg lifted in case it was being pulled down by a fault elsewhere. Still bad, new RAM is on it's way. Update: 4564 RAM arrived, while the pinout is the same the timings are totally different - now getting a bar of sparklies specifically when the full screen blue tile sprites are drawn (start screen). I noticed the bar disappeared when a probe was placed on the CAS line for the bank of ram, so decided to try replacing the LS157 this traces back to (pin 9). New 74LS157 made no difference. Ordered 4164-12s to see if it makes the bar go away. Success! |
| Silkworm (4) | Sound sometimes drops out | This was sold to me with audio problems - initially it sounded fine, but when I put a little pressure on the sound section it jumped in volume, vanished, came back again and so on. I think the volume jumps were actually the pot, this was removed, exercised to clean, and resoldered. While i was doing this I noticed a resistor which had no solder... Soldered this properly, reflowed the amp 'just in case', and now the sound is stable. |
| Sky Adventure | Sound effects gone | Visible damage here, the row-of-pins mounted resin covered audio chip was missing (later discovered in the bottom of the shipping box...) Repair for this is basically like Jaleco input board repairs - scrape off enough resin to reveal some pin metal and carefully solder that bastard back together. Works fine now. |
| Sky Shark (1) | Player 1 turning right | Easy fix - tracing back from P1 right on the JAMMA connector, one of the LS240s that handle control inputs was jammed low. Replaced this, fixed. |
| Sky Shark (2) | Unreliable boot, quiet static from speaker. | See Flying Shark entries for background info. Guess which cap was hanging half off, was the wrong voltage, and for some reason was tied to ground with a wire? Replaced this with a correct 470uF/25V cap, tidied up the hackjob where it was fitted, and the game reliably booted. Traced audio with the oscilloscope, the audio was clearly being generated but the amp was hissing. Replaced amp, sound fixed. |
| Solar Warrior | Background mis-tiled, sprites flickering according to frame | No brainer this one, half the pins on the bottom board of the rom sockets were bent over and touching eachother. Nice. This is why boards have legs, please note.. |
| Soul Edge | Vertical graphic glitches, affecting 3D engine in a flickery kind of way | A seller had shipped this to me from the US in some bubblewrap and a plastic bag (seriously), and the board had developed some kind of flex/warm-up problem. After lots of testing and pressing on various chips on the top board, it was traced to a series of RAM chips. Reheating the surface mount legs on these (urgh) made the problem go away. |
| Space Fire Bird | Shot and enemy explosion sounds missing. | This is usually down to the 74LS05s in IC22 and IC23, but on this occasion they looked OK. The next common failure are the LM324 op-amps, and sure enough one of them had died (IC24 I think), replaced both to be on the safe side - sound restored. |
| Space Fire Bird (bootleg) | Green missing from sprites, sync failed, sounds missing, stars intermittent, etc | Another ebay.de special sold as working but not. Intermittent stars was a RAM seating problem on video board. Green missing from sprites was one of the 3 colour caps (C3) having a broken joint. Sync problem traced to a mess of a semi-working transistor and a nasty big wire hack - pulled the crap off and put a new one in. Missing shooting effects were down to the capacitor that sits between the tone/duration pots on the sound board not being there. Various filter caps in the sound section were also wrong or missing. Two transistors in the sound section had been removed and bridged. Spent hours rebuilding this board according to the schematics and it works fine now. Last remaining issue is a red raster flash when your ship is destroyed. Should be full screen (allegedly) but isn't. Tagged this as fixed until I see another one to know if that's true. |
| Splatterhouse | EEPROM BAD | Initially suspected to be the ROMS, these checked out OK. The actual EEPROM on the CPU board also checked out fine. After checking with a known good CPU board, it was clearly a fault on the top (rom) board. Gut feeling swapped the 64A1 custom sound CPU with a known good one and the game worked fine. Returned this board to the owner as-is, 64A1 is nearly impossible to source. |
| Squash (Gaelco) | No sound | The amp and volume pot were both physically damaged. The pot was a simple metal clip casing so I repaired it, but the amp is pending replacement. Replaced, all good. |
| Strato Fighter | Strong green tint | The colour in this game is created by a bank of 3 PALs AAA16K4P-35, which then filter through a variety of flipflops and counters before reaching the resistors and caps at the edge connector. In this case I traced from the edge connector backwards, until I hit those PALs. If one fails, the colour it's dealing with will be stuck on - in this case green. The PALs are identical on this, Shadow Warriors (Ninja Gaiden), Tecmo Knight, World Cup 90 and possibly other Tecmo boards. Got a replacement from a Shadow Warriors, mostly fixed the issue but left a slight colour imbalance. Replaced all three with SW ones and it was fine. Also noticed sparklies on the backgrounds at the top of the screen - this came down to one incorrect RAM on the video board, -12 instead of -10. Switching sockets with one of the -10s was enough to clear the problem up. |
| Super Pang | Boot to dark green screen | Applied suicide fixed as per Dead Battery Society page and it was just fine :) Unfortunately this forced a re-regioning to World revision instead of Japanes, but it's better than dead. Read the instructions on that page carefully as it's a little more involved than CPS1 fixes, also take note of the NVRAM clear. |
| Super Pang (2) | Incorrect colours on desuicided board. | Previously desuicided, but someone had broken the raised pin on the ROM in 14h clean off. Burned new rom, reattached the wire, done. |
| Super Zaxxon | Blue missing, sounds crackle after a few minutes running | Tested and working. SO WHERE WAS THE BLOODY VIDEO BLUE PIN? Repaired the missing edge connector pin and blue is back. The sounds are the same problem as Future Spy, fixed, see above. |
| Takeda Shingen | No sound, missing samples | This worked until the donation of its baseboard to Saint Dragon (2), also now also has a faulty romboard, one of the two OKI chips (the lower one I think) is sick. Checked RAM on sound 68k, no activity at all. Checked 68k - absolutely dead. Piggybacked 68k and saw activity, cut out and replaced but still no sound. Next I replaced the two RAMs connected to the 68k and the music came to life. Samples still missing, checked the OPL chips on the romboard and found that one was dead. Replaced this and all sound OK! |
| Teenage Mutant Ninja Turtles (1) | Sound distorted while any samples are playing | Resoldered cap joint/etc - seems to have made no difference. Maybe this is related to one of the op-amps, or maybe this uses a two channel amp which gets upset if both try to play? Update it's better, but still not fixed... I resoldered lot's of audio components - but I suspect one of the op-amps has bit the dust when warmed up (C324C 16 pin). Update replaced the one I thought was at fault, but it hasn't changed matters. Pretty sure this *is* actually a cap issue after all.. Lost track of replacements, will do the whole lot. Update After replacing various sound section parts, I can only conclude there is some internal PCB damage on this board. It is parts now. |
| Teenage Mutant Ninja Turtles (2) | Not running | The left most small blue crystal (from edge connector point of view) had a leg ripped off. Repaired this, board runs fine now. |
| Teenage Mutant Ninja Turtles (3) | Graphics corrupt, doubled sprites | Started by checking the SMT chips, no problems there, next started looking at the sprite ROMs. Noticed with the finger test that all four had a slight effect on the picture. Checked more closely, and pin 3 of all four sprite ROMs was stuck low. Traced this to a 74F151AN in G6 with stuck outputs. Replaced with 74F151APC to fix. |
| Tenchi Wo Kurau II | Dead | This is a CPS1 + Qsound board, which have two suicide batteries. Taking the case off and checking, the Qsound battery was dead. Applied the Qsound fix detailed at the Dead Battery Society page (http://www.arcadecollecting.com/dead/dead.html) and this revived the game. I also took the hacked rom to remove suicide from the romboard, and applied the changes made between US hacked and US original to the Japanese rom. Along with the romboard fix also detailed on the site, the Japanese version rom 23 is here: http://www.system11.org/temp/ROMs/tk2j23c_x.zip |
| Tetris (Sega 16A) | Dead | Expected it to be suicide but it wasn't. Note: these older 16A boards use LOADS of power, make sure your loom and adapter are fully wired or things will get pretty warm. I had two of these, so I cheated and swapped the video boards, reseated all the cables, and it works! |
| The Punisher (1) | Dead | Q-Sound suicide as detailed on the Dead Battery Society pages - easy fix. Later I also applied the C board fix while doing another one as I'd dismantled it for testing. |
| The Punisher (2) | Dead, poor picture. | Q-Sound had been desuicided by a previous owner, but not properly! R33 and the capacitor nearby were both still intact, they'd even switched the Kabuki for a Z80 but you still need to make those changes. Did them and the C board fix and it came back to life but the picture was faded due to poor contact on the edge connector. Used metal polish and then alcohol on this and it's fine now. UPDATE: the fan was way too noisy - had to modify a standard box fan to fit, and ended up replacing the double sided edge connector from the front by carefully cutting one from a brand new fingerboard - speaker noise GREATLY reduced and no more burned pins. |
| Time Soldiers | Every other pixel of every second line incorrect colour on some graphics | Done a lot of investigation on this - there's a back of 8x 6116 ram, I've noticed that the effect gets worse if a certain data line on any one of four of them is probed. These all trace back to a LS153 but it looks OK even when piggybacked. Not going any further with this until I build a small adapter to read the 23C1000 28 pin mask roms. |
| Top Gunner (1) | Display faded, colours bleeding | I'd seen this before on a Bosconian board, and it can sometimes be indicative of a bad video ground pin on cabs where vid gnd on the monitor is not already connected to common ground of the loom, relying on the board to supply this. Sure enough, vid gnd track near the JAMMA connector was broken. |
| Top Gunner (1+2) | Booted up with 'bad color ram' error and the board location of the big Konami resin block | On closer inspection, resin block had a broken pin. Fixed this, board back to life, easy! (now done two of these with identical faults!) |
| Top Gunner (2) | Corrupt sound (initial) | I've noticed this corrupts the sound until the jeep has crashed once and played a particular sample. I suspect some kind of reset signal on bootup is not happening. Board has had some work in the past near the sound section. UPDATE: gave this to a mate as a freebie, it won't get fixed. |
| Twin Cobra (bootleg) | Sound corrupted, mostly a series of odd pitches sort of in time to the sound effects | Easy fix - one of the pins of the YM3812 was loose due to lack of solder. |
| Up'N Down (1) | During running, screen froze. Game only gave a black screen after this. | Pin 6 of the custom Sega Z40 (the clock pin) was stuck high. Tracing this back through IC142 (74LS04 inverter) to IC141 (74LS161 counter) showed one of the counter inputs (pin 10, ENT) was neither high nor low, jamming the counter. Tracing pin 10 up the board to IC44 pin 6 (74LS107 flip-flop) showed the flipflop was jammed. Lifted pin 6 and the problem remained (not high or low) but the game started running again (wrongly). Replaced the 107 and board runs fine. |
| Up 'N Down (2) | Sort of rasterised sprite corruption generated by some sprite frames and not others. Weak sound effects. | I think this is probably a sprite ROM or RAM problem, not diagnosed it as yet. It was sold to me as working (as usual). Diagnosed as a sprite ram fault. The Midway board version has 4x 2148 RAMs near the two sprite ROMs. Changing the positions of them changed the broken sprites, so each was swapped out until the broken one found (last one of course..). Still getting slight sparkly trailing edges on sprites when moving - this is because the new 2148 isn't fast enough, so it'll be replaced as soon as. Update:Playing this recently showed the sound effects were weaker than they should be. A quick visual check showed the polyester capacitor closest to the amp had a corroded and broken leg, replaced to fix. |
| Up 'N Down (3) | Jailbars over the whole screen, sprites corrupting, colours fading, tile corruption | This was actually a parts board I decided to try to fix. Jailbars turned out to be a broken track from one of the 2148 RAMs to the CPU in the bottom right corner. Sprite corruption was a failed TMM2009 near the sprite ROMs. At this point the tile corruption started on the logo - I was unable to diagnose that fault before the colour section started to drop out. |
| Vanguard | Dead | The simple things are often the best ones to check first. The crystal was dead as a dodo :-) Finding the 11.289mhz crystal proved impossible, but 11.2896 is a common one used in radio equipment - someone mailed me a couple :-) |
| Vapor Trail | Dead, green screen + reset, corrupt text, corrupt backgrounds. | This board was a mess, looks like it had been wrapped in spiderweb and wet paper. Started by probing various bits of RAM near the CPU ROMs, found one where the pulses would change and flicker when it was touched in position K7 on the mainboard. Replaced this, board booted to a screen of green bars and started resetting. Checked more RAM in the CPU area, found a suspect one in F5, replaced this and the game booted! Background graphics were jailbarred and flickering, text flickering and corrupt. The ROMs are all talked to via 74LS373s, touching one in the romboard corner made the text corruption change. Further checking found that the track between one of the 373 inputs and the CN1 interboard connector was broken. Wire jumper fixed the text. Background graphics changed when another 373 in D17 was touched. After much tracing of the inputs and outputs, two more broken tracks from pins 7 and 14 were located between some unpopulated ROM sockets which form the track path. All fixed :) Happy about this one as I like the game and had written this PCB off as dead. |
| Vasara | Lost sync, blocks of colour only | I could hear the game running when coined up, so immediately suspected possible SMT join failures. Sure enough, under a large heatsink lives the main SETA graphics CPU. Lots of high density pins, several of which had broken joints. Took a long time to fix, but it works now (suspected damaged due to inadequate packaging). |
| Vendetta | Half of the control inputs failed | This arrived "working", but obviously hadn't been tested properly. All the left/rights and all the credit buttons were dead. Tracing the control inputs, all the problem controls came down to two 74LS253s in 9A and 11A. These encode the control inputs and send them to a Konami custom chip. Oddly, they appeared to be outputting correctly, but probing the output pin on either made the inputs go berzerk. Suspect internal damage to the chips had occurred, replaced both, board now fine. |
| Volfied | Dead (physical damage) | Taito love their nasty resin covered daughtercards. They especially love using very thin, fragile pins to hold them on, and this one snapped off. Use a stanley knife/craft knife to cut away some resin covering and expose a bit more leg. Clean all the solder holes out, then fill with solder one at each end. Carefully hold daughtercard in place and melt the solder in the end holes to anchor it. Fill remaining holes. This is how to replace resin card parts the legs have snapped off from. |
| Vulcan Venture | Missing backgrounds, corrupt gfx | The missing backgrounds were easy to sort - one of the roms had the GND leg hanging out of the socket. This left me with the corruption issue. Test mode reported "P18" bad, which is F18 in reality. Most VV boards are 3 layer types, the smallest board having 32 character roms on it. The problem is, the sets in mame are all with 4mb mask rom images from the 2 board version, F15->F18. On the split rom version, F15 reports as F16, F16 as F17, F17 as F15. and F18 as F18. Yeah, thanks Konami. There are 8x 27512s for each of the 4mb rom images, labelled with the F number, and A->H. To get the right segment out of the 4mb image you must treat them as 4 sets of 16bit split pairs. A = set 1 lower bit range, B = set 1 higher bit range, and so on. The only exception to this was F18 for some reason, which has the two middle sets switched. None of the others do. Thanks again, Konami. After spending some time working this out, all the ROMs checked out as being OK. Testing the sockets of that bank showed part of the F18 bank had a broken address line track. Repaired it, corruption gone. |
| Vulgus | Garbled background gfx, no sound, faulty inputs | Doesn't even make a 'pip' from the speaker on boot. Amp was quietly cooking itself and was replaced with a new one, which fixed the sound. Garbled tiles were down to a faulty ribbon cable connect between the boards. Inputs (coin and p1 up stuck) came down to two 74LS367s which sit next to the edge connector, which had shorted the relevant pins to ground. All fixed now! |
| Wardner (1) | CRAM ERROR | Initially reported CRAM ERROR, then by the time I got it upstairs to the repair bench, it turned into total death. With the code ROM in place, the board would just hang on boot, with it removed various parts would come to life and start resetting. I started checking the CPU RAM address lines, and found address A8 was dead on one of the RAMs - a track must have been either cracked or about to, under the RAM. Wire jumper has fixed this, back to CRAM ERROR. I started checking the RAM I suspected to be for colour (had a good idea after diagnosing a Flying Shark), and found a pair of RAMs, one of which has nearly all dead IO lines, while the one next to it looks healthy. Piggybacked a good 6116 with the data legs lifted, and sure enough they pulsed away. Either the RAM installed is dead or something is holding the lines down, I'll have to snip a leg to find out. |
| Wardner (2) | I/O ERROR, no sprites | I/O ERROR can happen when coin inputs are jammed. Checking on the JAMMA connector, coin 1 was stuck low but the supporting resistors/etc all looked good. Replaced 74LS240 in N20 which fixed this. Missing sprites were very obvious - all the sprite RAM was physically broken. Replaced all 6 and sprites came back to life. |
| Wonder Boy | No sound (tone) | The sound CPU looked absolutely dead. Swapping it for a good one resulted in the same sound, but at least the address lines started pulsing. Checked the sound EPROM (matched the one in the System 2 set) and found it could not be read. Replaced to fix. |
| World Cup '90 (bootleg) | Title screen graphics missing, pitch drawn incorrectly. | This is a board flex issue - it works fine when it's warmed up, but I haven't found the problem despite many hours of reflowing and checking. Going to give it one last check when I have some freeze spray, after that it's joining the parts pile. Now used for parts. |
| WWF Superstars | Everything turned Cyan and Yellow! | I traced this by nonscientifically poking around, to a pair of very badly replaced and socketed rams (IC19/IC20, top board). I refitted these and made the hack a little more robust - and it works now. |
| X-Multiply | Small amounts of background corruption | This was sold to me as perfectly working - it was a shame to find out it was a conversion kit type, but more of a shame to see blocks of score readout appear in very specific places throughout the game. The tile engine is on the bottom PCB, so I switched this with the one from Air Duel (known working) and the problem went away. I then tried this with another known working baseboard, and it failed again. For some reason, this mainboard (an ex Ninja Spirit) only likes one baseboard (also from a Ninja Spirit). Why this should be is anyones guess - it makes no sense since all three work and are identical except for make and speed of RAM. Air Duel is happy with all three of the bases... |
| Xtom 3D | Hideous noise from board cage, freezing | Xtom 3D is a PC in a box. buried under the layers of ISA expansion cards, is a Voodoo Banshee graphics chip. DO NOT let this fan expire completely. Renewed all fans, noise gone. |