Game Maker Won't Boot Up

[racer881]

FIXED - I replaced the MPU and now it is working great.  Thanks to all the members who helped with this!

Bally V7217 Game Maker will not boot up.  Continually resets with blue screen with some clutter. 

Battery and power supply module (not the entire power supply) replaced, wiring and all connectors checked and cleaned.  All green lights on the main board.  Does the same thing with game chip or clear chip installed. 

The monitor seems to work OK when the game is started with the main board not installed.  Any ideas on what I should try next? 

Thanks

[kcirrick]

A wild guess:

If you pull the monitor out you will see the connector it plugs into with a ribbon cable coming out of that.  Make sure that ribbon cable is securely connected to the backplane board.  Also, make sure that the monitors connector isn't loose in a way so that when you install your monitor it doesn't get a good connection - make sure the monitor is well seated. 

I just had a monitor issue on my Revenge From Mars pinball machine.  It wouldn't come on at all.  I disconnected the monitors cable from the computer and sprayed it and its connection on the computer with contact cleaner.  I also opened up the computer and disconnected and sprayed the relevant ribbon cable and it's connections.  I gave it a few minutes to dry up, reassembled and my monitor was working fine.

So, if just reseating cables and the monitor don't help, perhaps spray some electrical contact cleaner on those connections.  It may not help, but it won't hurt and often the simplest solution is the correct solution.