Help diagnosing why PC freezes intermittently?

[Logickle]

Hi all. I know this kind of problem is tricky since it's intermittent, but so far has always occurred some time after a reboot. But there are particular symptoms I'm hoping someone else has seen. (By "freeze" I mean the images on the monitors freeze and the power stays on, but the keyboard and mouse have no effect, and the HD light shows no activity)

My config:

Antec case w/500W Earthwatts power supply
Biostar TA760 M2+ motherboard
4GB DDR2 800Mhz RAM
ATI Radeon 3400 fanless PCI-Express vid card

Set up for 3 monitors, one connected to the onboard ATI 3200 Radeon's DVI out, the other two to the two DVI outs on the 3400. Using onboard Ethernet via a wireless-N "gaming" adapter for internet access.

I've tried re-seating everything but the problem persists.

PC originally had Win7 32b w/a Samsung 1GB drive when it started exhibiting the problem.
Now has newly-installed Win7 64b on a different 1 gig HD (Seagate), still exhibits the problem.

Unfortunately I don't have any other known-good parts to replace with.

Doesn't seem to depend on what I'm doing, either.

Peculiar symptoms:

- The two monitors connected to the 3400 just "freeze", but the one connected to the onboard 3200 goes to sleep, saying "no signal".

- Clicking the button on my MS wireless mouse+keyboard base station, plugged in to USB, has no effect - normally it would start flashing while looking for devices to talk to. So it looks like it's not getting power over USB, even though the PS is still on.

- Neither the reboot nor main power switches on the front works, even though the PS is running, and when the PC is working those switches do work. Once the system freezes I have to reboot via the PS power switch in the back of the PC. This points to a hardware problem, since whether those switches work should be outside any software problems, as I see it.

Any ideas? Thanks!

 

[cdogg]

Video is definitely suspect. See if the same issue occurs when the 3400 card is not installed. Also try it with the 3400 installed but with the 3200 disabled (or left unused if you can't disable it in the BIOS). Perhaps one is faulty or they're not playing well together. Also check the driver making sure Device Manager shows that they are both using a WDDM v1.1 driver version.

-Carl
"The glass is neither half-full nor half-empty: it's twice as big as it needs to be."

[tab][navy]For this site's posting policies, click [/navy]here.

 

[DrB0b]

Not an overheating issue is it? Do you have something monitoring temps?

"You don't know what you got, till its gone..
80's hair band Cinderella or ode to data backups???

 

[vacunita]

I second the heat possibility. Make sure no dust is cloging fans and CPU dissipators.

Memory perhaps? Try removing all but one stick see if it happens again. Rotate memory sticks until issue re-surfaces.

Or run a memtest on all sticks.

----------------------------------
Phil AKA Vacunita
----------------------------------
Ignorance is not necessarily Bliss, case in point:
Unknown has caused an Unknown Error on Unknown and must be shutdown to prevent damage to Unknown.

Web & Tech

 

[FredWagner]

I second the Heat possibility. Are you running this with the case on or off ? Best results normally with the case ON, so the fans can give proper ventilation. Give particular attention to airspace above and below your hard drives. Also the 'fanless' video card - it may not have a fan, but unless it has a good amount of air circulating over it, it may be wishing it had one!

Fred Wagner

 

[rclarke250]

While looking for a heat issue, check the system for bulging leaking capacitors.

 

[Logickle]

Thanks to everyone, I'll pursue these different suggestions and report back. Right now running w/only off-board vid card, so far so good.

 

[cdogg]

Duh! Of course!!
I should have suggested checking for heat issues first! For some reason, I thought you had already mentioned checking that but apparently that's not the case!

-Carl
"The glass is neither half-full nor half-empty: it's twice as big as it needs to be."

[tab][navy]For this site's posting policies, click [/navy]here.

 

[BadBigBen]

Check your HDD and back up your data, ASAP!!!!

a lot of issues, like the freezing are an indication that not all is well with the hard drive that holds the system files, go to the respected HDD manufacturers site and DL their testing tool, e.g. SeaGate = SeaTools, Western Digital = Data Life Guard, etc...



Ben
"If it works don't fix it! If it doesn't use a sledgehammer..."
How to ask a question, when posting them to a professional forum.
Only ask questions with yes/no answers if you want "yes" or "no"

 

[FredWagner]

OP has had the problem with two different drives in the same machine. The hard drive problems can be real, and be caused (and cured) by the heat leavel they reach. Some years back, we had a "special" high performance machine spec'd for an important project manager. Instead of an IDE drive, it had a SCSI drive. And it exhibited problems like the OP describes here. When the regular techs couldn't solve it, I was called in. The drive was in a bracket in such a way that when the case was on, the case side of the drive had no airflow - it was snug against the bracket, and that was against the side lid of the tower. With the case open, it worked fine! I moved the drive away from the side of the case (used a different set of mounting holes) and the problem disappeared with the lid on, and stayed gone.
Similar issue one time with a musician friend who had multiple CD drives for burning CD's of his band. No airflow over the HD. Rearranging the drives to allow airflow over both sides of the HD cured the problem.

Fred Wagner

 

[Logickle]

Ok, some more data points:

memtest86 + (built in to the MB BIOS): 4GB - passed all tests
With only off-board vid card -> same freeze
With only on-board -> same freeze

I tried SpeedFan to get temps. I think that unfortunately SF didn't recognize my set up, since most temps and fan rpm's were only numbered (Temp0, Fan1,...), so I didn't know what each was measuring. The highest reported temp was 49C, which from what I found around the we isn't extreme. SF did apparently recognize the two HDs, both of which were running in the 36-38C range.

To the point about temps, I moved my PC out of its (ventilated) cabinet in my desk to ensure airflow was not blocked by anything external, same behavior.

I think I'll tear everything down again, including removing the CPU fan and re-greasing and re-installing. We'll see after that.

Some specs of my rig:

http://www.newegg.com/Product/Product.aspx?Item=N82E16819103989&Tpk=regor 2.9ghz

http://www.newegg.com/Product/Product.aspx?Item=N82E16811129024

http://www.newegg.com/Product/Product.aspx?Item=N82E16813138137

 

[Logickle]

Something else, I noticed a couple capacitors are bulging. Ie most are flat-topped aluminum-color w/a cross pattern, but a couple look just like the others but w/little domes.

 

[rclarke250]

Those bulging caps are bad, and most likely the cause of the issues. Check here

http://badcaps.net/

for more info.

 

[Logickle]

Thanks, found badcaps.net after reading your earlier suggestion to take a look at the capacitors while looking into heat. Thanks so much, I might never have looked at them otherwise.

So I sent an e-mail to Biostar support requesting a replacement mb, they tout this board as having solid capacitors for exceptionally long life, but apparently that only applies to some of the mb capacitors. If I can't shame them into replacing a board I've only had for 3 years I may dust off my soldering iron, or buy a (non-Biostar) replacement.

Strictly speaking we don't *know* the capacitors are the cause, but my first priority now is eliminating them as a cause if they aren't.

Thanks to everyone who's offered suggestions!

 

[FredWagner]

Have the problems started since the winter has arrived and the building heating systems have started to kick in? The winter/heated environment can also result in very low humidity, which provides a perfect environment for static buildup. Static discharge can zap a computer, sometimes causing permanent damage (I destroyed a keyboard once that way, felt like Thor!) and other times it can just cause a system to freeze. Wearing clothes of anything but cotton, scuffing shoes on the rug, can build up big charges in dry heated environment. It got so bad in one of my jobs, we kept a spray bottle of Fabric Softener for folks to spray on their clothes when they got clingy, indicating the static buildup. If this could be the situation, consider an anti-static chairmat, and cotton clothes, perhaps a humidifier, and see if the problem happens less often.

Fred Wagner

 

[Logickle]

Hi again. So I replaced the two bulging capacitors, and so far so good. The machine's been running now for a couple days straight, which it wouldn't have done before. I'll post another update in a few days, I want to try it now with my new vid card which takes a lot more power and runs hotter. If that works out then I think I'm in the clear. Thanks again for everyone's help!