Q*Bert freezes up after an hour of play?

[Coin-Op]

Long story short, I acquired a Q*bert in an incredible deal (more on that later). The game runs fine (playing or idle) for roughly an hour, then freezes up. It won't boot for several minutes after this happens, somewhere along the line of 30 - 60 minutes. What could be the problem here? I'm thinking either board problems or improper ventilation. What do you guys think?

[molton]

No experience with true arcade hardware, but it does sound like some kind of heating problem, maybe there are dead fans?  Or maybe the heatsinks need to be cleaned off and have some thermal compound reapplied to them.  Maybe somebody stole the heatsinks for copper?  Look for dirty looking ships for that I guess.

[boardjunkie]

I'd bet the board is not getting correct voltages due to either power supply problems/misadjustment, or connector issues.

http://arcarc.xmission.com/PDF_Arcade_Manuals_and_Schematics/Q-Bert_Instruction_Manual_(4-83).pdf

[Coin-Op]

The screen kind of flickers when playing it too. Could that also be a power or heating issue? I'll post results in a bit when i finish some scouting.