Dead CPU or dead motherboard

[myrgjorf]

Expert help needed

My daugther's pc (which used to be mine) has stopped working. I have nailed the problem down to a dead CPU or a dead motherboard. If it's a dead CPU I'll buy a new. If it's a dead motherboard I need a new computer.
Specs: AMD3400+ S939, MSI 7075 MB (oem), DDR400 RAM, Geforce 7800GS AGP. I'd like to reuse the GeForce as it's quite powerfull for her gaming.
Symptoms:
- All connected: fans starts running for ½ second, then PSU cuts off
- No CPU, all else connected: fans keep running
- CPU, 4 pin PSU connector to MB removed, fans keep running.
- RAM removed: same pattern as above.
All peripherials disconnected, another AGP graphics adapter connected.
I can't find another S939 CPU and I don't wnat to buy one if it will not work.

I think it is a dead CPU. Agree? Is the MB damaged?
Should I go the half way with a ASUS P5VDC-X ?

Thanks
Bjarne

 

[benzene]

I think its perhaps more likely that you have a dead PSU, can you swap it out for another to test?

 

[dragonsprayer]

why not suspect the psu - did your hook another psu to the system?

 

[mike99]

Try PSU first. Only way to tell between CPU & motherboard is by swapping. Check if local computer shop can test for you. If it IS CPU, you can still get Opteron 144 for about 52GBP which is a drop-in replacement, or look on Ebay.

Mike.

 

[myrgjorf]

Thanks all. I forgot to tell that I did try another PSU with exactly the same results. So I'm down to CPU or MB.

 

[Mendoza]

Sounds more like a PSU unit or Motherboard Issue.

CPUs that aren't overclocked by either Intel or AMD run for about 8-10+ years if not more as long as the fan on the cpu is spinning ( lets say dust and pet hair can clog up a fan easily). SO I'd almost 100% rule out the CPU.

Most likely either the PSU capicitors are dead/dying or your motherboards capicitors are dead/dying.

To identify if you motherboard is bad. Go look at the 4 pictures on the right of this page.
http://www.badcaps.net/pages.php?vid=5
The page has a few pictures to identify what bad capicitors look like.


If any of your motherboards capicitors are buldging or leaking fluid. Then its your board. But on a side note you can still find 939 boards (although very limited selection from newegg, tiger direct or zipzoomfly.....and last but not least ebay)

The PSU you can try hooking up a different one and see if the problem persists. But unless you know what you are doing I don't recommend opening up the PSU to look inside to see if its capicitors are dead, only because a PSU can still hold a charge for sometime even after being shut off and unplugged. Gettings zapped by a unhooked up PSU can sux ( i knowz)

 

[timaahhh]

I would take it to a tech shop and ask em if they can do a post test. 1/2 seconds might not be long enough however to run a post test. A post tester is a little PCI card that can run quick diagnositics and tell a tech the problem. If they try to charge ya I wouldn't pay more then 15 bucks, the post tester is sorta expensive for good ones, but really requires no work from techicians.

That may tell ya where the problem lies.

 

[Mendoza]

AH just read your post about using a different PSU.

Ya def you board then.

 

[Smoked Turkey]

99% sure it is not the CPU. The only time I have seen them go bad is Apples G5 chips that would cook themselves.

 

[superbigsoft]

Hi myrgjorf, could you solve your problem ? Can you share it with me ? Is it a dead CPU ?

 

[myrgjorf]

Hi superbigsoft

We decided by buy a gameable laptop for my daughter instead of trying to repair the old one. So I don't know if it was the m/b or the CPU.