Why is my computer freezing?

August 4, 2004 5:24 AM

ComputerRepairFilter: I need some help tracking down the source of a computer problem. [More Inside]

I was playing a video game recently when my computer froze up. This has happened before, and there is never a quick fix to get the machine working (i.e. rebooting doesn't work right away). If I tear apart the machine, clean out any dust and rebuild it it generally starts working again. Last night it didn't respond to this treatment.

What I'd love is some help whittling down the problem area. To assist you offering suggestions, here is what I experienced last night:

1) Machine would boot up but freeze at various points before Windows splash screen
2) Machine would boot up, get to windows login screen, dvd player would spin up (it had a cd in it), and when it stopped spinning the cursor would freeze
3) Took cd out of dvd drive. Machine booted up, got past login screen, opened up a web broswer and then the machine froze.
4) Machine booted up, got past login screen, froze before I could open anything from the desktop
5) Machine woudn't turn on, Machine would turn on for a few seconds and then stop.

Should I be looking at the Motherboard, the power supply or possibly the video card? The mobo has some diagnostic LEDs that show where the problem might be. I recorded at least 5 different problems when the machine wouldn't boot up completely. When I took the video card out of it's slot, there was dust on the AGP slot, but only at 2 spots on the slot (I think it's dust from the video card's fan being blown onto the slot). I also dismantled the power supply and found a white silicone type goo that had melted inside (I'm pretty sure it was not put there on purpose by the manufacturer since it didn't look like it was applied to a specific spot). I removed that goo and reassembled the machine.

Any suggestions would be greatly appreciated!

posted by smcniven to computers & internet (17 comments total)

Swap out parts for known good, if you can. Start with the power supply, then try the RAM, Video Card, and even the CPU if possible. To me, it sounds like the PS.
posted by angry modem at 5:47 AM on August 4, 2004

IANACRS, but I had similar problems with my pc a while ago and it turned out to be bad RAM. As angry modem said, swap it out for parts known good.
posted by sebas at 5:55 AM on August 4, 2004

And now you've dismantled your power supply, you've voided it's warranty, so it's probably a good idea to replace it anyway. Those things are designed to blow up when they detect that they're out of warranty, in my experience. Heh.
posted by armoured-ant at 6:18 AM on August 4, 2004

I'm assuming that since you had the case open you verified that all fans are functioning and none are dead or dying. If that's not the case, just replace whatever the broken fan is attached to, PSU, CPU, mobo/chipset, or video card. Otherwise:

1. Replace the power supply. Now. Don't turn it on again until you've done so.
2. Yank everything from the IDE cables except the boot drive. Does it work yet? Add devices back until it fails.
3. If it's still giving you woes, suspect the RAM.
4. If known good RAM still doesn't let you boot, swap the video card.
posted by majick at 6:46 AM on August 4, 2004

There are plenty of cheap, new power supplies on Ebay.
posted by swift at 6:57 AM on August 4, 2004

Okay, sounds like I'll start by swaping out a new PS. But now I have a few more questions:

1) My current PS is a generic product, and is not shaped like a traditional boxed ps. Instead it starts out square shaped by the fan, but tapers downwards on one side. At the back of the unit, the height is about half of the front of the unit. Will swaping in a new uniform ps cause me problems? (I don't think it will touch the CPU/Fan but the current ps give the CPU/Fan extra space where it tapers off

2) I just started reading an article about choosing the right type of power supply. They talk about +3.3v rail, the +5v rail and the +12v rail. Does this refer to the 3 seperate bundles of wires coming from the power supply (not including the connection to the mobo)? I've noticed that one of them has 1 connector on the end, the other has 2 large connectors and 1 smaller connecter, and the 3rd bundle seems identical to the second but has never been use. Does it matter which connector gets plugged into each piece of hardware (i.e. should my HD get a specific wire)?
posted by smcniven at 7:43 AM on August 4, 2004

short answer: if the plugs fit, it's fine.
posted by jeb at 7:58 AM on August 4, 2004

jeb, unless it's a Dell, which uses the same connector as standard ATX, but with wires switched around. Bastards.
posted by zsazsa at 8:31 AM on August 4, 2004

I believe the latest Knoppix CD has a boot option for memtest86. This tests your memory, which is pretty handy if you don't have spare RAM to swap in.

Also, you should check out the processor temperature. I know there are Windows programs that will ask your motherboard what its various sensors are reading, but I've never tried any. After running your computer for a while, you can reboot and access the BIOS and find out there.

If your RAM and CPU temperature are fine, it's almost certainly a bad piece of hardware... probably your power supply. Good luck!
posted by Eamon at 8:59 AM on August 4, 2004

I second Eamon's advice if there's no spare RAM to test (ask a friend to borrow their RAM for an hour if you have to).

But, this really sounds like a memory issue to me. Try swapping RAM into opposite slots if there is more than one stick. Make sure they are properly seated. If there are two, try just one.

Finally, if you do replace the RAM and find that there is still trouble. Check the BIOS settings for SDRAM timings and such tweaks against your motherboard makers default settings. Here's a decent BIOS optimization guide.

Good diagnostics methods are helpful. Remove all cards and devices, one at a time, until you isolate the problem. If you've got your PC down to video card, RAM, KB and mouse and are still having problems... then you can start to look into those things by swapping stuff.

Finally, that white "goo" that you found in your power supply is most likely white thermal grease (silicone or lithium) that is supposed to be there on the heat sink. You should probably leave that alone or, go to a computer store/radio shack, get a tube ($2.00) and put it back :)
posted by Dean_Paxton at 10:31 AM on August 4, 2004

wow - that dell thing appears to be true. amazing. don't buy dell.

thermal grease is only going to do any good if it's squashed between two components - it typically helps heat transfer from chips to cooling fins. if you cleaned it off an "exposed" surface then there's no need to replace it.
posted by andrew cooke at 10:40 AM on August 4, 2004

andrew cooke, fortunately you can buy an adaptor for Dells. They're still bastards, though.
posted by zsazsa at 1:44 PM on August 4, 2004

Just to follow up Eamon's answer: If you want memtest86, you might be better off just downloading it from their homepage--they have bootable floppy and CD images available, and it's something like 2mb versus a few hundred mb for Knoppix.
posted by arto at 2:54 PM on August 4, 2004

agreed. my opinion is that it's a heat problem. Either one of your fans isn't working properly, or you might just need another fan. You have a fan on the CPU, the PS, maybe the video card, maybe on the front of the case. Also, if you can boot it up and have enough time to check the temp in the BIOS and verify with the manual where the temp should be at. my 2p. Isn't there an online repository for stuff like this?
posted by escher at 4:44 PM on August 4, 2004

Well, I did a whole slew of things last night, to no avail. I think the problem is greater then the PS or the RAM. I swapped in a different ps, video card, brought some extra RAM in etc... I then ran memtest each time.

The problem is that after a minute or so memtest would freeze (generally around Test #3 or #4). I tried this with 4 different sticks of RAM, including one I borrowed from my pc at work and each time the same thing happened.

One final clue: each time the computer froze, it seemed as if the CPU fan changed speeds ever so slightly. Just enough to detect a change in the sound. Also, the pc speaker sometimes made a clicking sound.

That's it for me. I'm probably going to take it to a repair shop today. Unless someone thinks its a CPU or Mobo problem.
posted by smcniven at 5:46 AM on August 5, 2004

you don't happen to have a mobo with an extra little fan somewhere do you (not on the cpu)? if so, check is spins easily with your finger. if it's difficult to move and doesn't spin when the power is on, replace it.
posted by andrew cooke at 1:06 PM on August 7, 2004

(replace the fan - you can buy them separately. i had a similar problem with a fairly high-end AOpen mobo and finally tracked i down to the small fan on the chipset).
posted by andrew cooke at 1:07 PM on August 7, 2004