Yet more on termination issues: Tim Conway writes: "I couldn't get a new external 4.3Gb drive with an IBM mechanism to work on my PowerPC 8500/132 unless it was the only device on the external SCSI bus. If any other device was also on the bus, none of those devices showed up on the desktop or could be seen by Norton, FWB or SCSIProbe. I tried the drive on a friend's 7200/90 and it worked OK. I sent it back to the supplier, who replaced the SCSI ID selector switch. He tested it and found no problems, but when I got it back again it still wouldn't work on my 8500 unless it was the only device. Eventually, I used FWB SCSI Configure to change the ID of one of my internal drives from 0 to 1. The IBM drive then worked with other devices, but only if it was the last physical device on the chain (and therefore terminated). My supplier says some IBM drives are very sensitive to termination."
Update: Several readers suggested that this problem does not sound like a termination issue. It is more likely a bad cable or some similar cause.