Riptor
Well-known member
Im in the process of repairing a few Op Wolf boardsets and figured I would throw some notes up for the archives.
Main board #1
Symptom: Board booted and played 100 percent but would fail after a few minutes. A black screen would appear with "C chip no response" error. Occasionally "tilt" would flash just prior to the c chip error. This error was consistent and would happen after around 3-5 minutes. Rebooting the board just brought the error back. Only after a cool down period of about 10 minutes would the board reboot.
Solution: Searched the web for any info on the C chip error but came up empty. I assumed it refers to a custom chip. Since I knew it was a thermal problem I started hitting all the customs, one at a time with freeze spray. When I hit the TC0070 RGB module the game went from the error screen to fully operating. Ok, yanked one off a thrashed parts board and swapped it out. Same deal! So I figured it was something in the area was also getting cooled. I was right but was really surprised what it was. The problem was a bad 12.00mhz crystal. The board has run several hours rock solid. I have seen bad crystals a couple times before but never one that would work until it warmed up.
Main board #2
Symptom: Board boots and plays but screen only displays a turquois color and white.
Solution: I immediatly started inspecting the area around the RGB module and noticed some dark spots on some traces. Yep, acid damage and this board does not have a battery. Probably was caused by soda spilled down the control panel or was stored on a shelf next to a board with a leaky battery. I see this occasionally on pac boards.
I start ohming out the pins using my parts board to compare and I found that almost half of the traces to the module are open. About an hour later I finished jumping all the traces and colors are now back to normal. Ok, so the board is still not fixed entirely. I coin up and it starts a game on its own. Great, stuck start input. I traced the signal all the way back to the custom which controls I/O and thats as far as I got. This might be a tough one to track down because of the custom but I do know the custom is good so its something before it. Probably some more ate up traces.....back on the shelf for another day.
Sound board #1
Symptom: Zero sound output from sound board.
Solution: Checked the reset and clock on Z80, cpu is running. Sound rom was active as well. Probed the ram chip and found some noisy lines. Replaced the ram and the board was back 100 percent.
Sound board #2
Ummm, I forget. I really need to start writing this stuff down! Anyways it was broke and now its not
Sound board repair / diagnose tip:
Got a bad amp or suspect you might? The sound board has two channels that output the same thing on both sides. The game only uses one channel. You can remove the 5 pin speaker connector from the sound board and move the wires to the other two pins. You will now be running off the unused channel.
Main board #1
Symptom: Board booted and played 100 percent but would fail after a few minutes. A black screen would appear with "C chip no response" error. Occasionally "tilt" would flash just prior to the c chip error. This error was consistent and would happen after around 3-5 minutes. Rebooting the board just brought the error back. Only after a cool down period of about 10 minutes would the board reboot.
Solution: Searched the web for any info on the C chip error but came up empty. I assumed it refers to a custom chip. Since I knew it was a thermal problem I started hitting all the customs, one at a time with freeze spray. When I hit the TC0070 RGB module the game went from the error screen to fully operating. Ok, yanked one off a thrashed parts board and swapped it out. Same deal! So I figured it was something in the area was also getting cooled. I was right but was really surprised what it was. The problem was a bad 12.00mhz crystal. The board has run several hours rock solid. I have seen bad crystals a couple times before but never one that would work until it warmed up.
Main board #2
Symptom: Board boots and plays but screen only displays a turquois color and white.
Solution: I immediatly started inspecting the area around the RGB module and noticed some dark spots on some traces. Yep, acid damage and this board does not have a battery. Probably was caused by soda spilled down the control panel or was stored on a shelf next to a board with a leaky battery. I see this occasionally on pac boards.
I start ohming out the pins using my parts board to compare and I found that almost half of the traces to the module are open. About an hour later I finished jumping all the traces and colors are now back to normal. Ok, so the board is still not fixed entirely. I coin up and it starts a game on its own. Great, stuck start input. I traced the signal all the way back to the custom which controls I/O and thats as far as I got. This might be a tough one to track down because of the custom but I do know the custom is good so its something before it. Probably some more ate up traces.....back on the shelf for another day.
Sound board #1
Symptom: Zero sound output from sound board.
Solution: Checked the reset and clock on Z80, cpu is running. Sound rom was active as well. Probed the ram chip and found some noisy lines. Replaced the ram and the board was back 100 percent.
Sound board #2
Ummm, I forget. I really need to start writing this stuff down! Anyways it was broke and now its not
Sound board repair / diagnose tip:
Got a bad amp or suspect you might? The sound board has two channels that output the same thing on both sides. The game only uses one channel. You can remove the 5 pin speaker connector from the sound board and move the wires to the other two pins. You will now be running off the unused channel.
