Ok, this one is perplexing the hell out of me. I am about to give up.
I repaired this space invaders board that has a slight crack in it. It works 100% on the bench but not in my cabinet. I have jumpered the traces impacted by the crack and can flex the board pretty good on bench w/o causing any strange behavior.
Symptom 1: At first, I had the braze kit plugged in and it would constantly reset in the cabinet but not on the bench.
Notes:
PoR from PS is working fine as I have two other boards sets that work great in cabinet. However, I did swap power supplies, test voltages at board and all that jazz to be certain.
Reset/Watchdog ckt on daughter board (eg counters at D2 and E2) is fine as daughter board works fine on other main boards and behavior is same on this main board with different daughter boards.
Either the braze kit has a bit less activity on the sample line at boot up when game is in cabinet or the 60hz signal is not 100% and is causing D2pin15 to issue reset. It is watchdogging from D2pin15 but it has to be a timing issue.
I did measure the 60hz circuit at bench and it is @58.87 vs 59.xx hz.
Symptom2: I removed braze kit and put regular SI roms in. Game boots fine (no reset) but I get graphics issues. Again, game plays 100% on bench.
I am out of ideas and have spent way too much time on this board.