New Motherboard Problem?(I Think

[chang35baht]

Hi all. Got back to LOS 7 weeks ago and wife tells me she had to put the desktop PC into shop for repair. Seems they've fitted a new motherboard, AsusM2N68-AM plus. Now after 20-30 mins the pc shuts down on its own. The power button is still illuminated but the comp has shut down or has gone into sleep mode or something.

When I restart IE asks me if I want to restart to the last browsing pages as my comp. shut down unexpectedly.

Been back to the shop 3 times ( most well known shop in Chiang Rai) and 3 times they have told me they have fixed the problem. But no, problem still exists.

First time the Young kid in the shop told me there was a problem with the HDD.Which I thought wasn't correct. 2nd time he told me he opened the comp. all day and it never shut down, but I don't think he worked the comp. So when I took it back I left it with a couple of programmes running an a video running. Went back an hour later and yes, he said it shut down. Wife and kid picked it up last time. never got an expalanation as to the problem. But same scenario. Shuts down after 20-30 mins. This is variable not exact so no scheduled shut downs I think.

I'm usually using the comp. when it shuts down so not going to sleep I think also.

Taking this info from DXDIAG:Running XP pro,AMD Athlon 64x2 Dual processor, 4600+,MMX, 3Dnow (2 CPU's). Display Nvidia Gforce 8400 GS

THis problem has only manifested itself since the fitting of the new motherboard, which I don't know was a necassary refit or not as I wasn't here at the time.

The PC is only just over 2 years old and to be honest doesn' get a lot of use as I mainly use my laptop and the kids are at school in BKK so only use it when they come home on holidays.

My wife only uses the PC to talk to me on Skype when I'm away working.

Any suggestions as to the problem(s) would be greatly appreciated.

Thanks in advance,

Chang35baht.

[lomatopo]

Bad (failing) PSU, overheating CPU, caps failed(ing) on MB, general overheating (PSU/chassis/CPU cooler fans failing) are things I might look at.

[garyh]

Agree with above but also could be due to installing new mother board and issues with drivers installed over existing install. Can you do a clean install of windows and drivers?

Try turning off all power saving and see if there is any change.

Installing speed fan may help to identify any overheating issues.

Edited January 11, 2011 by garyh

[pjclark1]

To check for overheating

Run with the case off and a big room fan blowing onto the mobo.

Does it still shut down?

[chang35baht]

Will check these suggestions out guys.

Thanks for your help.

C35B

[Supernova]

Use CoreTemp to monitor temperatures. You may also want to check power supply voltages -- use HWMonitor or Everest (AIDA) for this. Play close attention to the +12V rail. Readings should not exceed +/- 5 percent (high: 12.60V / low: 11.40V). Anything outside this range may indicate a problem with the PSU.

Edited January 11, 2011 by Supernova

[barryw52]

Also worth Checking that the CPU heat sink/Fan is correctly seatedon the CPU this will show up if when you monitor the CPU temperature there okat start up but rise very rapidly to the point which it shuts down to protectitself. Agree it could also be power supply. The original diagnosis ofmotherboard may have been incorrect.

[mamypoko]

If temp. checks don't pan out, try your memory.

Remove all memory chips. Boot and run the computer with one chip only (this might take a while to identify a faulty chip).

Gook luck!

[Supernova]

Common symptoms of bad memory: distorted graphics, program failures, and system freezes/lock-ups. I've experienced all these just recently on my Core 2 Duo. As it turns out, a 512MB module was the culprit. That said, I doubt RAM is the problem here.

Random shutdowns are usually caused by overheating or faulty PSU.

Edited January 11, 2011 by Supernova

[prism]

Use CoreTemp to monitor temperatures. You may also want to check power supply voltages -- use HWMonitor or Everest (AIDA) for this. Play close attention to the +12V rail. Readings should not exceed +/- 5 percent (high: 12.60V / low: 11.40V). Anything outside this range may indicate a problem with the PSU.

You can also get some voltage and temp readings in your Bios start up program. Start up in the Bios program, navigate to Power and then to Hardware Monitor. It does sound like your PSU is at fault.

Edited January 11, 2011 by prism

[IBoldnewguy]

I would check control panel- power options - c/b settings are set to turn off after very short time - set to never.

[chang35baht]

Update.

Downloaded core temp and HW monitor. All seems fine except that the +12V colomn shows that the average voltage stays pretty steady at 12.74V. With a high of 12.80V and a low of 12.60V.

Have checked 3/4 times and always same.

Tempertures for core 1 and 2 remain pretty constant at 32-34 deg. respectively with highs and lows of 37 and 36 deg. respectively.

Checked inside case and all seems fine with fans etc.

I'm at a loss at the moment as to what to do next apart from take it to someone else to check it out.

Seems like that will have to be my next move.

Thanks for your help guys. Neat programs for monitoring your system.

Chang35baht

P.S. Sods law is in effect here as When I'm using the PC now it is fine, but if I Leave it downloading on vuze and I go out leaving it downloading with the monitor switched off. When I come home it has turned itself off.

How do I do a screenshot? I'll show the HW monitor screen.

Sh@t. Its just switched itself off. Lucky I posted 1 second before.

Edited January 16, 2011 by chang35baht

[lomatopo]

I'd try a different, known-good PSU as that 12V measurement is indicating a possible issue with the PSU and it is shutting itself off.