Thanks for your comments. I wanted to take the risk and try another board, because the failure was during a storm. There was a slight chance that the damage was there even if nothing appeared as burned. You are right in that I did not detect the exact symptom, which now looks more like stuck heads. Anyway, I got back to corner 0 as I have restored the original ROM chip and board to the drive and it is not showing the flash boot checksum error and boot prompt anymore, just as it was before. The motor spins up and the drive makes like 12 kick noises and then the motor stops, but there is no output to the serial terminal and it does not respond to Ctrl-Z. That was the original symptom. I notice that if I isolate the hda and or motor pins, even the good drives with Firmware CC1H and CC1J do not work, do not respond to Ctrl-Z or anything. Do you know if this method of entering Diagnostic mode has been modified on recent firmware versions? I have read many of the pages in this forum now and it looks like for my drive, apart from sending it to DR places, which would cost a lot for having messed with the ROM, I will only have the crude freezing or tapping methods. Do you have a way to search within the topics or the forum? Thanks again.