Dead PC

[lenos]

I recently built this PC and all was running fine. I had just installed a KWorld DVD Maker PCI card and was installing some of the software. All of a sudden the PC went dead as if power had been cut.

I've been following the troubleshooting guidelines from other similar posts and think I have a shorted motherboard. Here's what I've done so far:

Confirmed AC power to the ATX PS, and yes the switch is on
Confirmed switch (on front of computer) is working OK, to the connection on the MB, (just in case I tried shorting the pins at the MB with the same result)
I have 2 power supplies and checked the voltages on both (by hardwiring the appropriate pins ont he 20 pin connector and checking the others, they were OK) and swapped them back and forth with the same result

Here is what makes me suspect the MB is shorted. I disconnected all the drives and removed all cards except the video display card. I shorted the appropriate pins on the 20 pin ATX Power connector to start the PS and check the PS voltages with the MB connected, but the PS wouldn't start. Out of curiosity I unplugged the 4 pin 12v connector to the MB and the PS started fine. I suspect the MB is shorted here; any thoughts? How could the MB spontaneously short? Could my processor have suffered collateral damage?

Thanks for any help provided.

[azzey]

Nah... doubt it's the processor. Motherboard probably, could be shorted. No way to know really, unless you take the motherboard out of the case, set it on a non-conductive surface (like cardboard) and try to boot it with only the CPU, RAM, Video card, and nothing else. If it works, add back each devide one at a time until it refuses to boot.

Ensure that the CPU heatsink fan is plugged in. Also, try resetting the CMOS via the jumper, and replace the battery.

Please give us detailed specs on the system in question.

And also, welcome to http://www.pcguide.com/ubb/pcgubb.gif Discussion Forums!

Cheers!

[lenos]

Specs are:
ASUS P4GE-MX motherboard
P4 2GHz (I forgot exactly which) processor
512 MB memory
Seagate 100G HD (master) Memorex DVD recorder (slave) on primary
?? 20 G HD (master) generic CD (slave) on secondary
[Note this master slave configuration was chosen on purpose and was working fine]
Enermax Whisper EG365P-VE power supply ( This is what I put in orignially)
EZMedia 430W PS in there now
Windows XP Professional OS
Need any more info?

CPU fan is plugged in
I'll try the battery and CMOS jumper, and other tests and let you know what happens.

Thank you for your advice

[lenos]

OK I tried the CMOS reset and the battery, and taking the Motherboard out and setting it on cardboard, all to no avail, the result is the same. The only thing that will get the power supply to start is disconnecting the 4 pin 12V from the Motherboard. When I (foolishly) tried reconnecting the 4 pin connector with the PS running there were sparks at the connector, which would indicate a short there. So now my questions are:
Should the Motherboard be pronounced dead?
What else is likely to have been destroyed in the "Spark incident"?
Why would a motherboard spontaneously short? The whole system was running fine and just quit.
Thanks again.

[chrisling]

I guess the reason cause this fact is your area power supply. Try purchase a stablizer to stable the current flow into your computer. Sorry, can't help you much about your problem...

[david eaton]

Why would a motherboard spontaneously short?
had just installed a KWorld DVD Maker PCI card and was installing some of the software.
That could be the cause of the problem, if you flexed the mobo when plugging in the card.

[lenos]

That could be the cause of the problem, if you flexed the mobo when plugging in the card.

Even though it had run for 15 minutes or so after the installation?

[azzey]

Normally the short is present from the beginning, but David is right. Moving the motherboard around could have caused this (that's exactly what I was thinking reading the first time through). Also, you could have dropped a screw or something behind. Who knows.