Hey thanks!  I will try that.  I have had the headboard open though with my very limited knowledge of the kinds of electronics that it runs on, didn't want to poke around too much.

The 3 batteries (that are mounted remotely off of the back circuit board) haven't been replaced.  Ever.  They're not in a neat housing; they're kind of soldered together.  Wondered if that had anything to do with it though someone told me they simply maintain supply so that high-scores, etc don't wipe if the machine is unplugged.