I have a Gottlieb System 80a 1982 Devil's Dare. I am having an issue with the speech/soundboard. When you boot the game up after it has been off for a while, everything works fine. Then at about 15 minutes later (every time like clockwork) the speach starts to play with inconsistant pitch. It slows down to a low incomprehendable growl sound. After a lot of trial and error to solve this issue, I decided to leave the head open and clip a small desk fan to the case blowing towards the soundboard. That fixed the problem. I played for an hour that way with no issues. However when I turned off the fan (leaving the case open) the voice chip issue started up five minutes later. Just to be sure, I turned the fan back on and the problem stopped within a minute or so.
I want to put a computer case fan in the head blowing out the vents. I need recomendations on fans that would work well and also how to tie them into the power of the game. I am looking for simple as possible answers please.