Random Game Boards

Collection of some repairs I've made over the years on some random boards / systems. 

Crazy Climber Board Repair (Taito)

Sound Board, Climbing sound not right (8/23/23)

  1. Thought this was working, but during play testing I noticed the climbing sound was off, more of a beeping sound.
  2. Swapped AY8910 into working board, no change.
  3. Swapped sound roms into working board and found rom “12” was bad and causing the issue.
  4. Burned a new sound rom to fix the problem.

Video Board (Bottom board), Lines of video missing, dashes on screen (8/23/23)

  1. Board was working at one point, and didn't suspect anything like a damaged trace or bad rom.
  2. Probed around with a logic probe and logic comparator quickly, I didn't notice any bad ICs that I could check.
  3. Decided to actually look closer at the schematics and started checking the V and H signals. 
  4. Found a dead output at 74LS283 at 3R, pin 4. No activity at all. 
  5. Replaced 3R to fix the issue. 

Game Boots then locks up 001-007 (cycling through numbers) on screen – Swapped video board with a known working CPU board, determined video board has sprite issues, also swapped CPU board to find that it was causing the game to lock up in attract mode.  

Started with the CPU board, tested program roms, found one broken leg on a rom, but didn’t fix the problem.  Replaced ram at 2114 at 5A as I suspected the program rams might be the cause. This fixed the problem, the game now came and played, but was missing speech.  Checked the speech roms and AY-3-9810 but they were good. Noticed my other CPU board at the LM3900 replaced at some point and I know this op-amps go bad fairly often so I replaced it and the speech came back.

Video board still had a sprite issue with the main character (he was kind of outlined on the screen).  Again, I checked all the roms with rom burner, but they were all good.  Poked around the chips in the final part of the video section with no luck.  I started piggybacking the 2115 rams at 8J to 8P (with a 93425 ram, they are interchangeable).  Noticed when I piggybacked 8J the character would change to big block, but didn't see much changes when I piggybacked the other rams.  Replaced ram 8J and the crazy climber character was back.



Dragon’s Lair (Cinematronics)

  • Early revision boards have a socketed programmable chip (68705). I can’t program these, don’t have the original file, but there is a simple mod to eliminate this chip. I’ve done it before successfully. It is documented on Dragon’s Lair Project.   These early revision boards only support PR-8210 disc players. Make sure you have that setting correct when using Hi-Tech cards.
  • Later revision boards (no 68705 chip) support the LV-1000 disc player and are preferred for running the DLE roms footage (if you have that DLE disc)
  • Dragon’s Lair Enhanced roms (DLE) will work on both boards.  This rom set has different dip switch settings than the original rom sets (there are quite a few different rom sets).
  • Make sure settings are correct for the laserdisc player and then the conversion card you are using.
  • Be sure the ribbon cable connecting the Hi-Tech card to the main board is installed correctly.  The ribbon cable should be comin out the right side of the main board when the Hi-tech card is installed on the left side.

Beeps Twice, but doesn’t go further (1/31/24)  - Took a while on this one, board would beep twice, seem to work, but disc player wouldn’t play video.  Seemed close.  Test mode seemed to work as well when using dipswitch to test board

  1. Replaced all sockets as each one had a few tarnished legs. Not awful, but not great either. No change.
  2. Probing around board and everything looked good, ram seemed to be doing stuff, all socketed chips were checked twice. 
  3. Spent a bit of time checking jumper wires, thinking maybe something loose. No luck.
  4. Looking at schematics I suspected U20 or U21, these seem to interface with disc player. Didn’t notice anything odd with logic probe.
  5. Replaced U20 first (74LS244) for the heck of it, no change.
  6. Replaced U21 (74LS374) and board now works.  Bad U21 IC (both ICs were SA branded).

Board would boot to diagnostic tests (10/29/15) – tried switching dipswitch, but no changed. Swapped out AY-8910 chip (the test switch runs through this IC) and that solved the problem.

 

Exidy 440 Repair Notes (Cheyenne, Chiller, Crossbow, etc).

Few Basic Tips

  1. Check Reset (should be high) and clock signals on both pins 34 and 35 at 6809E as I have seen them going missing (seen one present and one missing).
  2. Use Fluke 9010a to test Program roms and rams.
  3. Self tests seems to test all of the other roms and the 6116 rams. I have seen one board with about 75% of the 6116 rams bad and cause basically a white screen, so you may have to pull these one at a time to test.
  4. Sprite issues are common and usually due to bad 2148/2149 ram at 15L and 16L.

CPU Boards

Cheyenne, sprites colors wrong, issues (10/20/14) – board was working but were off, colors were wrong and jumpy.  Replacing 2148/2149 ram at 14L fixed the problem.

Crossbow, sprites colors wrong (10/20/14) – board was working but sprites were off, colors were wrong.  Replacing 2148/2149 ram at 14L fixed the problem.

Crossbow, nothing on boot – (10/17/14) – clock and reset line looked good, used 9010a and found one program rom 5A was not matching 9010a checksum. Reseated the rom to fix the problem, but board had sprite issue (see below)

Crossbow, sprites mostly missing (10/17/14) – board was working but sprites were mostly missing with just one color.  Narrowed problem down to near 2149 at 14L as when I removed it sprites disappeared completely.  That ram was not the problem though, pins 12 and 13 were stuck low coming off of it, and replace 74lS173 at 13K fixed the problem.

Crossbow, sprites colors wrong lines in them (10/17/14) – board was working but sprites were a mix of colors, some lines, problem looked “ramish”. Ram at 16L (2149/2148) had already been replaced, replaced 14L but no change. Signals were pulsing on 15L, but I replaced anyway at that solved the problem.

Sound Boards

Cheyenne, no sound (10/20/14) – Touching sound pot caused sound to come back. Replaced 10K sound pot and sound was back for good.

Crossbow, no sound, “Audio Power Down” (10/20/14) – Came up with Audio Power Down message. Swapped out 6809P processor to fix that problem.  Board booted, but no sound.  Noticed 7812 voltage regulator was not outputting anything, replaced this to fix the board.

 

Super Off Road (Cinemat System)

Check 16Mhz crystal on top board, found at least three bad ones when working on these boards.

Bottom Boards

Graphic Issues, Sparkling (5/14/21)

  1. Started swapping socketed ICs (there are a lot of them), all tested fine.
  2. Retested board and it now works, guessing something wasn’t seated well.

Vertical Lines on Boot, no signs of life (5/14/21)

  1. Started swapping socketed ICs (there are a lot of them), all tested fine.
  2. Found a bad 4416 ram at U35. Grabbed another from a parts board and board now works.

Top Boards: boots to garbage (5/18/21)

  1. Swapping roms found a bad rom at U57, now boots but graphics aren’t right, white blocks on screen, cars move slow and are black to start race (but change back).
  2. Bad Rom at U6 fixed the white blocks on title screen, but cars still off and move slow.
  3. Bad Rom at U5 fixed the car color issue, they look normal, but still move slow.