CPS1 B Board repair

This capcom CPS1 B board (middle board) was running but the video output would not sync, usually this would be a C or A board fault but I'd already ruled them out by swapping them.

I went around the board checking the connection between the A and B board was solid with a multi meter and found two pins not making contact near the C board. This part of the board had taken a nasty knock at some point and cracked the near by resistor array in half, but one problem at a time.

First I desoldered the connector that had the two missing connections.

Now I could clearly see the two broken pins.

Once I replaced the connector with one from a scrap board sync was restored but there was a graphics glitch, most sprites had vertical lines going through them.

I replaced the two resistor arrays next to the c board as one was broken in half and one had a leg broken off. This made no difference.

I was convinced the issue was in this area since I'd already found so many other issues there. Running the board without the C board means the game won't work but it's the only way to access that area and probe around while the board is running.

I checked every pin on the two resistor arrays and noticed one was high while the others were all toggling. A closer look I could see the through hole had come away from the trace and probing the trace it was toggling away.

A tiny piece of kynar wire to repair the trace and the repair was complete.