PC Randomly Shuts Down

My PC randomly shuts down.

I have removed everything but the PSU, mobo, CPU and RAM. I am testing it by booting Ubuntu via a flash drive.

It is not overheating because I have checked this in both BIOS and using a program called GKrellM which monitors the temps. The dual CPUs are at 28 and 35 degrees celsius. I've never seen them go above 45, and it has often crashed when the temps are low, i.e. around 30 +/- 5).

It crashed anything from straight away (i.e. before BIOS has even had a chance to kick in), to a few days. It's most common uptime before a crash is 2-3 days with it running all the time.

I have remove all dust from PSU fan, CPU fan, and all heatsinks (overheating isn't the cause anyway).

I have tried three power supplies (ranging from 250W to 300W). It used to crash the same with all of these.

It used to crash with Windows Vista as well as Ubuntu, so it's not operating system specific (the crash before BIOS even loads is an indication of this fact also).

I have run memtest on both sticks of RAM. I have tried both sticks separately and in different slots and memtest is happy. Changing the RAM doesn't avoid the shutdown issue.

I have visually checked the capacitors and they are not bulging or bubbling (not that this proves beyond doubt that they are ok).

I checked the thermal paste and it seems ok, but again there is no heating issue according to stats, so I don't think that is the problem.

On removing the mobo, there was a metal clip underneath the mobo, so I wonder if this shorted it out and damaged it?

I am guessing that 250-300W PSU is powerful enough for running just the mobo without a graphics card or other peripherals?

It used to crash more often when there were more peripherals which initially made me think that the wattage of the PSUs was too low.


My primary hunch is that the mobo has an intermittent fault, or that the PSU is not powerful enough for my CPU, however I have been told it should be ok.

I have also checked whether the power button is faulty, as I heard that a faulty switch can act as if you have pushed it. However I remove the power button connector from the mobo and it still crashed even then, so this is also not the issue.


Here's the spec:

AMD X2 Athlon 6000+ Dual Core CPU
ATX-3000TF (FSP) 300W PSU (the others were of similar spec).
2GB PC2-5300U 667
Mobo is NF-MCP61 (Phoenix Technologies)

Detailed output from 'sudo lshw':

ubuntu
description: Desktop Computer
width: 32 bits
capabilities: smbios-2.2 dmi-2.2 smp-1.4 smp
configuration: boot=normal chassis=desktop cpus=2
*-core
description: Motherboard
product: NF-MCP61
physical id: 0
*-firmware
description: BIOS
vendor: Phoenix Technologies, LTD
physical id: 0
version: 6.00 PG
date: 09/06/2007
size: 128KiB
capacity: 448KiB
capabilities: isa pci pnp apm upgrade shadowing cdboot bootselect socketedrom edd int13floppy360 int13floppy1200 int13floppy720 int13floppy2880 int5printscreen int9keyboard

 

Xtreme PSU calculator puts you around a minimum of 200W with a recommended 240W. If the PSU's that you tried were of low quality then you could be at the borderline. I see you use *nix, try to find a burn-in app that stresses all your components at the same time for maximum power draw. If you dual-boot with Windows then try OCCT.

You've done everything else that I would have, either it's the PSU or the dreaded intermittent issue.

 

Thanks for your post augiedoggie

I did run a stress test on HDD (when it was connected), RAM and CPUs. It thrashed all of those for 36 hours with no problem. I should have mentioned that. I didn't thrash the GFX when it was plugged in (GeForce 8400GS 256Mb), but everything else was thrashed.

Because this worked for that length of time I am guessing in hindsight that it is not a PSU issue. I have never had a problem with the other PSUs in other machines so it is highly likely to be the mobo I guess. The PSUs previously ran other systems that never shut down, and these systems although having lower powered CPU did have all the peripherals running. A lower powered CPU with all peripherals can't be more power that just a mobo with no peripherals with a higher powered CPU. But I could be mistaken.

I believe it to be an intermittent fault with the mobo which could be anything. I doubt it's the CPU because I've trashed that for 36 hours.

Do people think my diagnosis is correct? I'm trying to save money by only buying the replacement parts I need.

It's been a painful journey with diagnosing this one, but I've learnt a lot so a hug bonus really.

 

You have to include the 8400 as that adds some 30W power draw, have everything hooked up when you next 'thrash your machine', it's the only way to get realistic performance data for your PSU.

I hear that you don't want to put good money into a bad machine but there's no other way to test except at max power draw.

 

Although it is true that the PSU can't be tested to it's full extent without the graphics card attached, it is invalid to say that we need to test it's capability at maximum power draw.

We have ruled out the PSU shutting down due to things sucking too much current because the system can crash even when it is idling without ANY peripherals attached (i.e. the problem occurs when there is not much current being drawn, and it sometimes doesn't shutdown when lots of current IS being drawn, i.e. the 36 hour stress test when it didn't shutdown). That proves that it is NOT a 'power draw', problem... therefore the test you mention does not need performing because it is not the issue of the shutdown.

Not that your test wouldn't be useful, but it is redundant in finding out about this issue.

Note also that I have tested THREE different PSUs all of which didn't have a problem when drawing higher currents in other systems that the system I am currently testing. There is ONE motherboard though, so probability is definitely pointing to that although I could be wrong.

Thanks for your help again though.

 

I'm no expert--I'm just curious what the make and model of the motherboard is I believe NF-MCP61 is a chipset. I'm just curious if there have been any BIOS updates in the last few years that might be applicable.

Most likely it is hardware fault but I'd just like to take a look.

 

Well spotted. I was mislead by the output of 'sudo lshw'.

The mobo is actually:
GeForce6100SM-M2 (V1.0A)

See:
http://www.ecs.com.tw/ECSWebSite/Pr...goryID=1&DetailName=Feature&MenuID=21&LanID=0

The BIOS seems to be out of date. As according to 'sudo lshw' my BIOS is dated 09/06/2007 whereas the latest available download is 13/06/2008 (UK date format).

Could this fix the problem? Is it worth flashing the new version of the BIOS? Do I need to install Windows to do so? (I'm guessing I do... darn).

 

Lots of people seem to get the shutdown problem with this motherboard:
http://www.fixya.com/support/t372407-ecs_geforce6100sm_m_powers_off_without

The most common fix seems to be the BIOS update (http://www.ecs.com.tw/ECSWebSite/Pr...ilID=685&DetailName=Feature&MenuID=24&LanID=9)

I am going to try that and see if the problem goes away. Thanks to everyone who gave input. If this is not the problem then I'll add another note letting people know so that future readers of this post can get help.
:-D

 

You don't have to have Windows to flash the BIOS you have to put the flash files on CD. If you need help let us know.

 

Just to confirm that updating the BIOS did not fix the problem for me. A lot of people have had problems with random shutdowns with this motherboard. The best fix is to return it if it's still under warranty or bin it and buy a new motherboard.

The only thing to do now is replace the capacitors but I'm not going to do that. I just think the mobo is a door stop

 

Thanks for posting back. Yes, I didn't see anything specific in the BIOS update that related to your issue so it was just a throw of the dice.

Sorry, I can't give any other suggestion. It appears you have done a thorough job of troubleshooting and are still having the problem which looks like an intermittent hardware fault. If anything jumps to mind, I'll post back.