Teaser re power supply or motherboard

Archived from groups: comp.sys.ibm.pc.hardware.chips (More info?)

I am trying to sort out a powering problem with a
friends Fujitsu-Siemens computer. The machine would not power up at all. I e
ventually got it running by using a paperclip between green and one of the b
lacks on the 20pin connector going to mother board, have also replaced main
switch to mb.

Where do I go from here - is it down to a mb problem ?
Is it safe to leave paperclip in 20pin connector when connected to mb ?
Does the paperclip test guarantee that the power supply is not the problem ?

Archived from groups: comp.sys.ibm.pc.hardware.chips (More info?)

On Mon, 11 Oct 2004 11:33:40 +0100, "tph" <tphiggins@broadcap.com> wrote:

>I am trying to sort out a powering problem with a
>friends Fujitsu-Siemens computer. The machine would not power up at all. I e
>ventually got it running by using a paperclip between green and one of the b
>lacks on the 20pin connector going to mother board, have also replaced main
>switch to mb.
>
>Where do I go from here - is it down to a mb problem ?
>Is it safe to leave paperclip in 20pin connector when connected to mb ?
>Does the paperclip test guarantee that the power supply is not the problem ?

If shorting the pins on the mbrd header for the case switch doesn't bring
it up and shorting at the P/S connector does, then there is obviously a
mbrd problem. Check the solder joints at the header and check for voltage
there too... otherwise it's likely deep in the mbrd traces.

I'm pretty sure the paper clip test is confirmation that the P/S is good
but I wouldn't leave a short on the P/S connector - the power switch on ATX
is supposed to be an instant on and off deal.

How old is the system and what chipset is this? There was a problem way
back with VIA chipsets having trouble with some flakey power supplies;
there were also some power-supply/mbrd combos which were extremely
sensitive to temperature - they would not come up if the ambient temp was
below ~67F... try a hairdryer on it to see.:-)

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??