This is a great thread. My first game was Meteor, and at one point a 5101 died and I put in a new one, immediately triggering the f-ed up spinner noise problem. On occasion I've swapped in an MPU-200 from another game to aid in diagnosis, and again have on occasion gotten the spinner-noise problem. I run my boards as original as possible (though I do install a super-cap instead of a NiCad), so have never tried the NVRAM, so never ran into that issue. I do have EPROMs since I've updated to divide-by-10 ROMs from Oka Egi's site.

I was unaware there was a fairly significant revision on the early MPU-200 boards, and will inspect my (likely original) Meteor board to see if I have the fix or not. I was also completely unaware of the "bug fix" factory U1 ROM (and have absolutely experienced the bonus-countdown infinite-loop: Typically on a game where I was about to defeat my high-score!). I'm curious if anyone knows of divide-by-10 ROM images with this fix? I do like running 6-digit displays on Meteor, even if it is blasphemy to have no trailing always-zero digit!