Computer almost dead. What could have gone wrong?

[Serge]

When I push the power-on button only the fans and neon fan lights go on for
a second and then everything is dead. A little bulb near the memory modules
stays lit, though. Nothing happens then when I push the on button again
until I push and hold it for about 5 sec. This makes the "memory light" go
off. I guess at this point the power is completely off. Pushing the on
button again repeats the whole process.
After numerous ons and offs and disconnections of power cord and hard
drives, etc the power may suddenly turn on and everything starts spinning
(all the fans and drives) but the machine wouldn't boot at all. The screen
is blank and there's no indication of power going to any of the peripherals.
The impression is that only fans and the drives work (spin).
Well, I did have some hardware changes (added a new sata drive) and I also
flushed my bios 2 times. First one was unsuccessful (wrong bios file), but I
didn't have a problem because I have dual bios. Second time (with the right
bios file) the flush was OK and the system booted nicely a few times. So I
don't think the bios is at fault here.
I do think something might be wrong with the power supply ( FORTRON SOURCE
FSP530watt-60GNA).
Even before the hardware changes I remember on couple of occasions not being
able to turn my computer on. It took then a few flips with the power switch
in the back to turn it on.
One more thing to mention. We have frequent power outages in the
neighborhood and my computer stays on at all times. Could those power
outages eventually have damaged the power supply. Unfortunately, I don't
have an APS unit, only a surge protector.

Thanks a lot in advance for any help.

 

[Frankster]

Probably one of two things. Power supply or electrical short on a component
(Switch, HD and/or Motherboard). I'd say the power supply is the most
likely. Since you can buy a new power supply at your local computer store
for around $30, I'd say try that first. You should be able to set the power
supply up, even if you don't bolt it all the way into the case for testing,
and find out real quick.

-Frank

 

[Mike Hall \(MS-MVP\)]

Serge

The best way to determine if the power supply is at fault is to put one in
that you know works well.. if the computer doesn't boot up, and I suspect
that it won't, you are looking at replacing your mainboard..

 

[Richard in AZ]

When you turn the computer on (front switch) a signal is sent to the PS to
start. The PS has an internal test circuit that checks for a stable 12 V
and 5 V output. If valid, it send a signal to the MB and the MB continues
to request power. If this "power valid" signal is not received by the MB,
the power supply is turned off.

Hence the problem could be either the PS or on the MB. Easiest check is to
try another PS. If a known good PS does not work, try removing all cards
except the video card and try again. If no go, you have to replace the MB.
If it starts without the modem, etc. Replace one card at a time until you
find the one that is shorting down the power bus.