my Data General Nova 4/X, disk woes continue

[Eric Smith]

Tony wrote:
> I am never in favour of shotgun replacements. It's the brother of
> board-swapping in that you don't know what the fault was, you don't know
> you've found it, so you can't know it's fixed.

I'm not a fan of shotgun replacements.  Board-swapping can be a useful
diagnostic measure, in that if you swap a board out and the machine
starts working, you have most likely isolated the fault to that board,
making it easier to focus your efforts to track down the actual failed
component.

I've found this technique to be especially useful when the symptom is
sporadic flakyness.

Of course, if you're not careful, it's possible that there was some
fault that damaged that board and will damage the one you swap into
its place.  At the very least the power supply voltages should be
checked before board swapping.

Eric