hardware issue

[Alma J Wetzker]

dep wrote:
> this is strange.
> 
> this morning my desktop machine just stopped. shut down.
> 
> it's an athlon 2.3; i thought that maybe the chip fan had died and 
> had therefore shut everything down, but the fan certainly moves 
> freely. i can't tell more than that because the switch, which is one 
> of those non-switch switches, has no effect in bringing power to the 
> machine.
> 
> my thought is that i popped a fuse in the power supply, but i can 
> find no external fuse socket.
> 
> i'm utterly at a loss. informed adice, ill-informed suggestions, and 
> anything else would be welcome.

There is often a fuse inside the PSU.  It is not meant to be user serviced (if 
at all).  The ATX PSU's provide a 5V line to parts of the MB to get the 
"instant on" feature.  There is also a power good line that needs to be 
dropped to ground (I think a green wire) before the unit produces general 
power.  I am assuming that you are using a UPS so I am not thinking power 
fluctuations.  A short in the case can cause those symptoms.  If you have a 
spare PSU, try it.  If not, you can short the green wire (I think) to ground 
(a black wire) to see if the PSU fan spins.

Are you still getting juice from the UPS?

     -- Alma