Hi guys, I'm having some trouble with my 1996 Indianapolis 500 machine. It has had an intermittent reset issue that has been going on for about a year now. It cleared up on it's own for quite a while and just came back. Just to be clear, this is a reset (machine cuts completely off and turns itself back on; not a tilt or anything like that).

I have some ideas and I'm looking for more advice. First off, if anyone has the wiring schematic for this game, that would be awesome. I had some other issues and had to chase wires down by hand.

I checked voltage at the wall and the auxiliary outlet inside the machine, getting a solid 120 VAC. Measuring TP1, I'm getting 5 VDC, which should be correct. On J101 though, the red wires are 5.3 VAC and the blue/white wires are 8.7 VAC. The other end of these wires (where they first come out of the transformer) are basically the same, maybe 0.1 V higher. I was under the impression these wires should be carrying 9 VAC and 13 VAC, which leads me to believe the transformer isn't working correctly.

The fact that I'm getting 5 VDC on TP2 seems odd to me but the only thing that I can think of is that the bridge rectifier is working correctly, but struggles with the low input voltage during high power draws. It's not consistent, but I have seen it reset after hitting both flippers at the same time. At other times, it does seem to reset whenever there is a lot of action on the playfield.

I'm new to pinball repair so I will mention this as well, just in case it means something. The reset issue seems worse when it first starts up and gets better the longer you play it. I read elsewhere online that this is typically caused by a thermistor issue, but I don't see one on this machine. Unless it's hidden inside the power box...

Any advice you guys can provide would be greatly appreciated!

Awesome, thanks for the help. When I get the time, I'm going to dive into this deeper. I'll post back if I find anything.

In case it helps anyone else, I wanted to post back and let everyone know that I had been checking the voltages incorrectly. On J101, I was checking the voltages against a ground braid / common DC ground. Being AC, you should check voltage from one red wire to the other red wire and likewise one blue/white to the other blue/white wire. Doing this, my voltages are reading correctly.