check the jumper settings on the drive... It's been a while since i played with scsi stuff, but there might be more than just the scsi id jumpers? Maybe you need to terminate the scsi chain; I have an SE/30 who's internal drive is invisible until I hook up a terminator to the back of the case (literally, i'll turn it on and sit at the blinking question mark for X length of time; the second I attach the terminator to the back of the machine, I get the happy mac and it's up and running)