On Apr 14, 0:40, David Williams wrote:
> Subject: AT&T 6300 PSU Question
> I went to power up my AT&T 6300, which hasn't been up for about 4
> years, and noticed that the PSU fan was coming on but the drives and
> motherboard didn't seem to be getting power. I opened up the system
> and was surprised to find the power supply was corroding.
> You can see pictures of it on my web site on the AT&T 6300 page
Jason's comment about liquid sounds about right. It looks more like something
was spilt onto it, than as if something self-destructed. Anyway, it's usually
electrolytic capacitors that self-destruct in that way, and that normally
happens when there's a voltage there.
> Any ideas? Also, anyone have a spare PSU? I don't really want to go
> buy another AT&T 6300 just for this but suspect the PSU won't be easy
> to obtain otherwise.
I'd attempt a repair, or at least some further investigation.
The case looks pretty yucky but from the pictures, the physical damage might
not be that great. I'd take it apart and attack the case with a wire brush or
steel wool, and a very light touch of oil or WD40. The terminals don't look
too bad at all, a little brushing (stiff toothbrush preferred, or a brass wire
brush or fine steel wool) and a little WD40 should work wonders. Make sure you
wipe off any excess WD40, though.
Depending on how bad it is inside, it might be worth washing, but do make sure
that (1) any capacitors are discharged before you get it wet, and (2)
everything is *completely* dry before you try applying power! Again, a
toothbrush is a useful tool.
In many similar PSUs, the fan is driven from the 12V line. If that's the case
here, it implies that at least part of the circuitry is working, which is very
encouraging. Perhaps only the 5V line is dead. It's hard to suggest much more
without more information, and without seeing the inside.
If you do try anything, apart from the obvious precautions, be aware that there
are some very high voltages inside switch mode PSUs, as high as 300V. Also,
many PSUs won't operate correctly without a load on at least the 5V line; at
best, they won't regulate properly, at worst, they can be damaged.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
Received on Tue Apr 14 1998 - 09:01:14 BST