On Sun, 30 May 2004 17:03:58 -0700, "ynotssor"
wrote:

A borrowed machine was being placed in a new environment for the first time.

The power cable was not fully seated into the power supply on the back of
the machine, and when power was supplied, there was a flash and a pop. Power
was removed from that machine, the cable was checked for damage, the power
inlet appeared normal (although there was the distinct electrical odor for a
while).

The power supply was removed and examined, with no visible signs of damage
or gross electrical odor. A small apparent fuse within the ILSSAN ISP 120S
Rev. C-2 appeared normal, as the small copper strip was continuous and no
discoloration of the glass wall was evident.

After re-assembly, the power indication light on the front of the box does
not light when the main switch is pressed on, nor is there any other type of
system activity.

The question is, please: Is it likely that a simple power supply replacement
will solve the problem, or is it possible that the main switch has been
damaged? I can't find a pinout diagram for the power supply, so don't know
which connectors to test for continuity to the main switch etc. where it
connects to the backplane

A replacement power supply is about US $25, but I wanted to check with the
wealth of knowledge here about what to do or consider before possibly
wasting the money. I'm well aware of the general eMachine opinions and agree
with them, but this box is borrowed.

Thank you.

"Main switch"? If you mean the switch on the front of the case, no,
that's extremely unlikely and impossible given only the problem you
described. I am assuming this is an ATX, not AT, power supply. Ignore
following paragraph if it's an AT.

Take out the power supply, disconnected entirely from system then attach
to it a load (old hard drive) on 5V rail (just plug in the hard drive if
that's what is used) then attempt to power-on power supply by shorting the
PS-On (usually green wire, pin 14) to any ground (black) wire.
http://69.36.189.159/usr_1034/atx_on.gif

If it's an AT, no shorting of the PS-On wire is needed, instead just flip
main front switch.

With either type, after shorting PS-On or flipping swithch the power
supply should turn on, it's fan spinning, and hard drive spinning. If you
have a multimeter then take measurements of voltage at connector.

If power supply won't turn on, consider it dead and try another one. Only
after you have a known working power supply can the rest of the system be
tested to determine if it was ONLY a power supply failure. After a system
has been moved there are other potential problems that might've shorted
out power supply, like a dislodged heatsink, loose wires, a misplaced
motherboard standoff, etc, so examine system interior for any signs of
trouble, double-check all cards, cables, etc. One everything appears
correct, THEN try connecting new power supply with only minimal parts
installed or connected to power and motherboard, that is - CPU, 1 memory
module (or two if RIMMs), video card, heatsink fan.