Ramdom Computer crash - Confused

[Reggie12]

A friend of mine asked me to fix his pc. It randomly stops all input and output and can only be shut down by unplugging the power; sometimes when it is booting up, sometimes when it is idle and sometimes and when playing any game. Ive tried updating every driver i can, ive re-installed XP and ive tested the GFX card, RAM and CPU in a different system and no crashes. There is no visible damage on the mobo and nothing in the event log and i cant figure out what is causing this.

Does any one have any idea what it could be and if it is fixable; or should i just tell him to buy a new mobo?

[Lucio]

First thing I'd do is replace the hard drive cables, they're not that expensive and whilst it's an uncommon fault you've covered most of the basics. Whilst you're at it, try using Speedfan or similar to check for the S.M.A.R.T. data on the HDD, see if any errors are being reported there.

After that, consider testing the PSU (not in another machine!), there's some fairly inexpensive PSU testers around.

[peterb]

After that, consider testing the PSU (not in another machine!), there's some fairly inexpensive PSU testers around.

I would certainly consider the PSU as the cause of the problem, but those inexpensive PSU testers are just a waste of money. They don't apply any meaningful load to the PSU and so don't test it in any useful way at all. All they tell you is if one of the voltage rails is missing, but tells nothing about the capability of the rails that are present.

In the absence of a proper dummy load test rig, the only effective way to eliminate the PSU as the cause of the problem is by substitution.

[Splash]

When you say you have tested the other components in another machine how long did you test for? Did you load them at all?

I'd be looking at Memtest86++ for a good 8-12 hours on the RAM personally, though the PSU is equally possible.

[Dingo]

As a matter of interest what is the airflow like in the case and have you used any temp monitoring at all as excess heat is a symptom of what you describe. Also does the pc have a hdd activity light as a visual to any activity when it freezes?

[HSK]

bios upgrade? might be worth a shot.

[peterb]

TBH, a BIOS update would be one of the last things to try. If the system has been previously working correctly, the BIOS is unlikely to suddenly start giving problems. (The only exception might be if an application making a lot of low level BIOS calls has been recently installed.)

BIOS upgrades are potentially one of the riskiest things that you can do to the PC, because although not difficult to do, if anything goes wrong during the process (particularly a powerfailure) or the BIOS image is corrupted, you stand a good chance of leaving your mobo in an unuseable condition, from which recovery may be difficult or impossible. (Although most BIOS upgrade programs do check for image corruption)

[HSK]

^ good advice. yes i forgot to add that be real careful in doing that (if u do as a last resort) and make sure u have a back up of the orginal bios (or the one u were using) incase a newer one give u more probs.

[Reggie12]

Thanks for the advice, Im sure the airflow is alright, he has a zalman GT900. Ive tested it with my PSU which i have no problems with and it still crashes. I tried replacing the HDD cable and no luck.
He did tell me he used a hoover to get rid of all the dust and it started crashing after that; my first thought was static.

Everything except the mobo and PSU are in a different system and have been working fine for 2 days so im pretty sure its one of them.

[Big.Wayne]

Does any one have any idea what it could be and if it is fixable; or should i just tell him to buy a new mobo?

Hi Reggie,

it always help if you include full system specs when making posts like this, its not clear at all what hardware you are using. ALso worth noting the age of the hardware (new/used) and if any new kit has been recently installed.

[Reggie12]

Its alright now; he got a new mobo and PSU and its running fine

[ianc1990]

Yeh, the mobo was probably the most likely cause!

Could have been due to static but i doubt it would have had such a bad affect!

I hoover my computer our weekly without worrying and it costs £2000

Even shorted my mobo and seen sparks and smoke before but still working fine :S

I must just be lucky eh