Hi everyone,
New to the board and a novice and am hoping someone can help me with my Qbert.

Game will play well for awhile and will screen will then go blank. I can leave off for a day or so  and it will turn on and play for hours and then same thing. I inherited this machine and when I got it the Switch on the top was not connected. I reconnected it and it seems to turn on and off properly so not sure why it was disconnected. I have read it is notorious for power supply problems.

Where do I start?