Recently I pulled out a PCB to play and instead discovered I had a CV1000 with no signs of life, no flashing LED’s, nothing. I was quite distraught as these boards are pretty expensive. This worked perfectly in the past but had been stored away and unused for some time.

I was a bit lost at where to start but decided to start poking around anyway. After a while I noticed there was no 3.3v being generated for the logic IC’s, instead I was only reading 0.1v. The CV1000 runs on 3.3v logic, so obviously this was no good. After inspecting the board and looking up some of the IDs of the smaller chips on the PCB, I found there are two DC-DC converters (U29 and U31 - 2651MTC-ADJ) on the bottom left beneath the sound amp, that are used for converting the JAMMA 5v to 3.3v. I thought these were likely the culprit, but The circuitry is difficult to trace as this board has some inner layers that cant be followed by eye. Given these PCBs are quite expensive I was a bit hesitant to do anything as I didn’t want to do further damage.

I posted online and unfortunately didn’t have much of a response. After a few days of building up courage I sat down and compared the regulators with a working PCB, I was getting some irregular readings for U29. I decided to try a simple re-flow, and as luck would have it that sorted it out.

And with that I had a working CV1000 again.