I picked a nice Firepower a few months ago and it has played great, with an occasional lockup when playing. Lately it has been happening more often. I can now make it occur consistently just by pressing both flippers at the same time. The whole machine locks up and requires to be powered off to reset. Otherwise it plays great.

The previous owner put in a new sound board and power supply board. The MPU was also serviced before he sold it.

Any obvious things to look for? I'm not an electronics expert, but can poke around a little if needed.

Thanks!