CPS1 C-board failure

[TMF68k]

The C-board failure is confirmed, but is it still the B-21?
I tried to replace the PAL.
But it didn't change.
I replaced it with a different C-board and it showed up fine.
Please let me know if anyone can help me.

 

[MegaMan]

This might be what you need. I’m not very experienced with arcade board repairs but this chip may fix your issue without having to replace the entire C board.

http://www.ukvac.com/forum/capcom-cps1-cboard-fix_topic369210.html

 

[TMF68k]

This might be what you need. I’m not very experienced with arcade board repairs but this chip may fix your issue without having to replace the entire C board.

http://www.ukvac.com/forum/capcom-cps1-cboard-fix_topic369210.html

Thank you for the information.
What I'm saying is exactly what I need to replace this B-21.
I hope that is not the cause of the failure, but I want to know if the B-21 is the likely cause.

 

[TMF68k]

In the end, the B-21 was confirmed to have failed, so I stripped it.
I'm going to rebuild it into a 92631C-5.
It's okay to pattern cut the blue wire, but are the resistors and diodes in the red circle necessary?

 

[Nebula]

Yes, you need to populate all those elements to make that model C-board (92631C-6) to have the capabilities of key-programming and storing then using battery power. But you also need to make some missing traces in order to send the signals to B-21 when programming keys.

We compiled more info about that in this thread: https://www.arcade-projects.com/thr...a-90631c-5-battery-backed-b-21-c-board.13116/

 

[TMF68k]

I understand that 42 and 44 are connected to CN19 and CN20 respectively.
Is there any other difference in the circuitry?

OK, I was going to restore it properly, but I'll leave the battery stuff in place.
I'll do the minimum amount of wiring and make it a multi-donor.

 

[Darksoft]

I've got a 2-3 units of B-21 here, if you need any, PM me.