Usually when a game just resets after start up or during gameplay once or twice its the silver 5 volt reg.
After u reseat all cables everywhere, and if it still does restarts and weird stuff, email Beaky about replacing the 5 volt reg, get a price to have it replaced, very very easy fix and not that expensive to do at all....one of the first things i do to alot of my machines if they ever do exactly what you have mentioned....
Brett, you're as bad as the posters on KLOV - any issue with a monitor and they all scream "fit a cap kit" - hahahah
The power feed connectors are a very common problem on these games - the 5V reg doesn't give any where near as much trouble as it gets blamed for - do the resistor mod as per Clays (ex) site and you will fix most of the 5V reg issues WITHOUT replacing it.
The 5V reg design was VERY poor engineering at the time and it always should have had a pot or at the very least a resistor to adjust the 5V rail.
This procedure is even covered in the datasheet for the LM323K:
Who knows why this was never implemented from the factory - cost? - maybe, to prevent boofheads twiddling the 5V rail, more likely IMO.
For the original designers to think that there would be ZERO resistance in all of the PCB tracks, connectors, crimps and cables between the 5V reg and the micro reset circuit was madness! I'm surprised they don't give a LOT more trouble.