Used a logic probe, found 3I had a pin that was stuck low, so that's the one I swapped out. The blank 4k high scores were at least staying... Before they were a mess and changed with every boot. I've reset everything, and it looks normal now. We'll see if they revert to chaos before Brad's adapter shows up tomorrow.you have to manually do Restore Factory Settings, Clear Bookkeeping Totals, and High Score Table Reset and see if the blank 4000 point scores go away. if they keep coming back then the switcher is probably messing it up.
what was your procedure for replacing the shift register? how did you decipher that particular one was bad?

Another thing, however... once again, if I leave the back off the glitchy graphics aren't happening. Anyway, progress was made today. Thanks again for the help!

