External scsi tape drive disappears

[Bill Hassell]

> If we were to suppose that the issue was with the system board, wouldn't I also see issues with the network connection or usb ports which are also on the same bit of pcb?

Not at all. The system board is a bunch of components so unless a common failure such as a power supply was at fault, each component can fail intermittantly and independently. If a memory controller were to fail, everything would crash but a memory chip could fail and the OS may be able to deallocate the bad area of RAM.

So in your case, assuming that the cables and termination are OK, there's 50:50 chance that it's the drive or the SCSI controller on the system board. If this is happening on a replacement board, you may want to try another tape drive.