I'm in the throws of trying to diagnose a nagging issue with my Totem machine starting (game starting) intermittently. It boots up fine. Been going through the PinRepair page looking for things to check. I'm pretty sure the switch signal is getting to the CPU board. I've checked the diodes on the bottom board and they're within tolerance. Ground mods and caps have been done/replaced. I checked the input voltages to the CPU board and they also look OK. Cleaned all the edge connectors.

Right now I'm taking a look at the transistors on the driver board. I removed the board and I'm doing the checks described on the PinRepair page. I'm able to get good readings on the right leg of the transistors (I'm testing Q1 - Q4) but the left leg on all of these registers nothing. I'm guessing I must be doing something wrong in testing them, as when my game does start...everything works fine.

I guess my general question is what should I check/test? I'm wondering if something in the game PROM controls the game start and I might need to flash a new PROM (I did have to put a heat sink on it to stem some scoring oddities). Is there any way to attach a logic probe to the machine and find out where the start signal dies? I'm guessing the signal goes to the CPU board (J6), then driver board then eventually energizes the game over relay to start the game. Is this correct? Grasping at straws here. Any words of wisdom?

Thanks Rooster. Your ideas are putting me in the right direction. Story goes that I bought the machine from someone who did all the requisite upgrades (caps, grounds, etc). I undid the diode coupling for the free play just to eliminate variables. It coins up EVERY time. But it has issues with the start button intermittently. By that I mean it won't start a game most of the time but will on occasion. Maybe it's the other end of the Start switch that is causing the problem. Over.

Tried to start the game without J7 connected. Still won't start a game.

The diode in line with the start button seems to read fine (around .21). Is there any chance that it could still be what's causing the issue -- should I just replace it to eliminate variables?

I used a pencil eraser to clean the edge connector. But I just used my continuity test with the J6 connected to the board and I'm able to get continuity from the traces on the board to (a) the other side of the start button diode, (b) the blue/black wire on the other side of the switch. I would seem to think this indicates a good connection to J6.

I'm pretty much convinced the issue is NOT a bad connection but instead some component that is acting up. When I power the machine on cold the start button does not fire. Once left running for a given amount of time (maybe 10 mins to 1/2 hour) the start button begins working. And it seems to continue to work. Does anyone know which chips play a role in sending the start signal and how I could go about testing them?