27 Oct
2005
27 Oct
'05
12:43 p.m.
You know, that always surprises me - I'd expect board swapping to rarely
cause problems for reasonably modular systems (I can believe it with
such as DEC hardware though, where you so much as cough near it and
something breaks ;)
OK, one that bit me (it's not a board-swap, it's a module swap, but...).
The fan in this PC's PSU decided to fail (bad bearings). I didn't have a
fan in stock, so foolishly, I grabbed a 'spare' IBM-brnaded PC/AT PSU
from the shelf amd swapped it in. It would be quicker,
I thought, than
extracting the fan from that PSU and popping it into the existing
PSU.
Result : the machine didn't power up at all. It turned out that the 2
PSUs were of different makes (although both IBM labelled), and both met
the IBM spec _which specifies a minimum load on some of the outputs). The
'old' supply had been happy with less load than that, then 'new' one
wasn't. And of course my modern hard drive didn't put much load on the
12V line. It would have been quicker, and a lot less hassle, to just swap
out the fan.
-tony