PC wont POST

[weaksauce]

Hey guys,

I was out of town for 3 days and after getting back home last night my computer would not POST upon powering it up. I usually never shut it down since I'd use it a few hours later - Only leave it on Standby and restart it.

This problem has happened once before but I got my computer to start up again after powering on and off, disconnecting all wires from the back, reconnecting, it mysteriously started up.

Symptons: After I hit the power button, it will just turn on and then off after a few seconds. It keeps rebooting itself in random intervals - as little as 5 seconds to 3 minutes. No beeps at all. There is no display signal going to my monitor. No power going to mouse or keyboard. CPU fan and case fans all have power. Video card fan spins. DVD drive has power.
I have not installed any new hardware recently.

System (about 3 years old, stress tested with Prime):
Intel E6750 clocked at 3.2ghz
Gigabyte P35C-DS3R (forgot which firmware)
Freezer 7 Pro CPU cooler
2 gb Crucial Ballistix
MSI Geforce 9600GT 512mb
Corsair HX620W PSU
WinXP Pro SP2

Appreciate any help. Let me know if you need more information.
Thanks!

 

[Twoboxer]

The way you worded it, have to ask - is your cpu fan spinning ? And while you were gone for 3 days, did you power off that time or use standby? Sorry.

Are mouse/kb USB?

Is CMOS battery dead?

 

[weaksauce]

The way you worded it, have to ask - is your cpu fan spinning ? And while you were gone for 3 days, did you power off that time or use standby? Sorry.

Are mouse/kb USB?

Is CMOS battery dead?

CPU fan spins
I actually just reseated the CPU and fan today, just in case.
AND replaced the CMOS battery.

While I was away the computer was shut down. The other 2 times this happened it was both when the computer was powered off. It never happens on standby which is why I usually use that option.

mouse and keyboard are USB

 

[rambo117]

it would least likely be the CMOS battery (they last almost forever). have you tried to reset BIOS?
also, check and see (it probably isnt but wouldnt hurt to check) if there are any screws or metal parts touching your mobo that could be shorting out your computer.

 

[Twoboxer]

After clearing CMOS and re-setting your BIOS, assuming the problem is still there, the last quick thing to check is to remove all USB cables from your mobo and boot the system as far as it will go. Then shut down, attach a PS2 kb only and try again to see what happens. If that works, or if you have no PS2 kb avail, install your usb kb and try for power. (The idea here is maybe there's a USB issue that can be cleared.)

If that doesn't locate or clear your problem, need to look for a short in some other device by trying to boot with minimal equipment installed. Nothing, add one stick memory, add keyboard, add HD, add vid card, etc.

 

[hundredislandsboy]

Sounds like it's not getting enough power to reach POST. Do you have spare PSU to troubleshoot?

 

[weaksauce]

it would least likely be the CMOS battery (they last almost forever). have you tried to reset BIOS?
also, check and see (it probably isnt but wouldnt hurt to check) if there are any screws or metal parts touching your mobo that could be shorting out your computer.

I doubt it is the CMOS battery as well. The same thing is happening with a new one.

I will try to reseat the mobo today.

 

[weaksauce]

After clearing CMOS and re-setting your BIOS, assuming the problem is still there, the last quick thing to check is to remove all USB cables from your mobo and boot the system as far as it will go. Then shut down, attach a PS2 kb only and try again to see what happens. If that works, or if you have no PS2 kb avail, install your usb kb and try for power. (The idea here is maybe there's a USB issue that can be cleared.)

If that doesn't locate or clear your problem, need to look for a short in some other device by trying to boot with minimal equipment installed. Nothing, add one stick memory, add keyboard, add HD, add vid card, etc.

The CMOS should have been cleared when I replaced the battery, correct? Currently the only thing connected to the system is the monitor. I can't get a display signal at all.

I'll try reseating the MOBO today.

 

[weaksauce]

Sounds like it's not getting enough power to reach POST. Do you have spare PSU to troubleshoot?

I'll be trying to narrow down the problem at a friend's house today.
I do have a feeling it's either the mobo or psu.