Namco system 12 - resetting but occasionally boots

[rememberizer]

I have a Tekken Tag board that just keeps resetting itself. The cpu board works, but I recapped it anyway. Bottom board was also recapped and reflowed. Occasionally, the amount of time between resets will change, and sometimes the game will actually boot up, but it's so rare that it's just frustrating to use.

Anyone know how to fix this?

 

[Franco23444]

There’s definitely something wrong with the cpu board, probably some bridged or loose pins on the Sony chips? Probably when taking off the top board, some flexing may have happened that caused some pins to come loose on those Sony chips.
Do you have another system 12 cpu pcb to test out? I had a similar issue with a soul calibur that I recapped and the cpu board was originally working before the recap.

 

[rememberizer]

Yes, I swapped the cpu board to another system 12 and it works.

 

[Franco23444]

Yes, I swapped the cpu board to another system 12 and it works.

Just out of curiosity, do you have a video of what the pcb is doing?

 

[rememberizer]

Didn't take a video because nothing shows up on screen. I can just hear the CRT picking up sync and losing sync over and over.