exxos's Atari, Amiga & retro forum

Yeah diag cart gives ROM CRC error normally, because it's based off a different TOS ROM to the one you are running.

If you’ve reseated the IC I would suggest taking them out one more time and check that no pin is bent. Depending how you remove them or if you mistakenly insert them with a slight angle you might bend the pins. Once bent you end up with a short which is not visible when inserted in a socket. (I’m talking about the PLCC chips)