Quoted from Biffbar:

Your Hyperball is behaving as it should. As Theonlylilo mentions, there have been modified roms which would retain the high scores. I went back to the normal factory roms.
There was a bug in one or more modded roms, if your batteries ever went flat, or were replaced, the game would get stuck in audit mode (until original roms were installed again). My machine sat for years, while I occasionally tried different 5101 ram chips, or poked around with a logic probe, all to no avail. Turned out there was nothing wrong with the machine, except for a buggy custom rom.