Comment on 'boardswapping' as part of the computer culture.
teoz at neo.rr.com
Thu Oct 27 16:08:04 CDT 2005
----- Original Message -----
From: "Tony Duell" <ard at p850ug1.demon.co.uk>
To: <cctalk at classiccmp.org>
Sent: Thursday, October 27, 2005 3:43 PM
Subject: Re: Comment on 'boardswapping' as part of the computer culture.
> > 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.
I guess it would depend on how long the PS was functioning without a working
fan as to whether I would replace the fan or junk the PS and get a new one.
Was the PS under warranty? If so better to send it back then to void the
warranty and fiddle with the internals (depending on costs).
For commodity PC parts that will wear out I tend to just replace them as
needed and keep spares handy. On items that are hard to find I will swap the
item when I can scrounge another and mark the old one as bad and put it on
the shelf hoping someday I will get a chance to fix it once I get a clue
what's broken (this is what I did with a Mac Quadra 950 PS I have on the
The PS swap you did was not a total loss, atleast you learned about the
minimum load needed in the system you have.
I don't like blind board swapping (where you just keep replacing parts until
it sort of works fine again), but don't have a problem with tracing the
error down to exactly what is causing the problem and then swapping that
part/board/assembly out. There has to be some kind of structured approach to
the problem, especially in a work type environment.
More information about the cctech