I may have realise that the enclosure SCSI ID selection is not working at all. So the drive is always at SCSI ID 0. I tried switching the selector elsewhere on the drive jumpers, no luck there either.

So, if at least I could get the jumper settings for SCSI ID (even if I had to fixed it for its life) that would be great. Internet in this case looks useless! And no real indication on the drive itself...