PC Shutdown Problem

[dyazdani]

I've got a strange issue - my wife brought a co-worker's PC home for me to fix. It runs fine (when it's running) but it randomly shuts down. The power doesn't just stop, it actually puts up the Windows shutdown/logoff screen and shuts down "normally." Sometimes it also shuts down on the Windows XP startup screen.

I turned off all of the power management stuff, but not sure what to do next. I feel like it's a hardware issue - power supply, something. Any ideas?

[Kevin P]

It could be something as simple as a sticky power button, or (more likely) the PC is infected with something. Try some online virus scans and see what they turn up. Also, Ad-Aware, Spybot S&D, CWShredder, and such stuff...

[RobP]

My wifes computer did that awhile back, it started out doing the same thing that you describe, but after awhile I started getting blue screens, I took out the RAM, blew out the socket and re-installed it, hasnt done it since.

[dyazdani]

It could be something as simple as a sticky power button, or (more likely) the PC is infected with something. Try some online virus scans and see what they turn up. Also, Ad-Aware, Spybot S&D, CWShredder, and such stuff...

Tried this last time I had it, didn't find anything - probably need to run another scan or two.

[dyazdani]

My wifes computer did that awhile back, it started out doing the same thing that you describe, but after awhile I started getting blue screens, I took out the RAM, blew out the socket and re-installed it, hasnt done it since.

I'll give this a shot too - I vacuumed it out last time IIRC, wouldn't hurt to reseat all the parts though.

[Kevin P]

To rule out a RAM problem, download Memtest86 (google for a link).

[dyazdani]

To rule out a RAM problem, download Memtest86 (google for a link).

Thanks, I'll try that too - I may have a few minutes at lunch, I'll let you know what happens.

[dyazdani]

I tried a spyware scan, darn thing shut down before the scan was completed...

Running Memtest right now, it is more involved than I had thought...

[dyazdani]

OK, now that sucks - as soon as I hit the "Post Quick Reply" button, the other PC (running Memtest) just shut down. No logoff sequence this time since memtest runs on boot.

I'll reseat the RAM and see what happens.

[dyazdani]

OK, I reseated every card on the mobo. One thing I noticed is that the way the power supply sits (in the middle of the case), its wires often restrict the CPU fan's movement. I'm going to try to pull them out of the way.

[dyazdani]

Nope, no difference. It won't hardly run 10 seconds now. It starts after you push the button, shuts off after a bit (usually around the BIOS screen), and tries to turn itself back on but fails.

Memtest made it about 40% through with no problems, but then she shut down.

[Arneson]

Look at the motherboard very closely.
Do you see where the larger capacitors around the CPU heat sink are bulging at the top?
If so the mainboard filter caps are failing and the power supply may also have leaking caps.
That's what I look for first now.

[dyazdani]

Look at the motherboard very closely.
Do you see where the larger capacitors around the CPU heat sink are bulging at the top?
If so the mainboard filter caps are failing and the power supply may also have leaking caps.
That's what I look for first now.

They don't look deformed in any way. I may try to find a spare PS at work and see if that fixes the problem.

[JustinSC]

Does the bios have a temperature reading for the CPU? Check the voltage levels through the bios(if it has that function) or with a multimeter. How many RAM sticks does it have? Does it have other cards?

[dyazdani]

Does the bios have a temperature reading for the CPU? Check the voltage levels through the bios(if it has that function) or with a multimeter. How many RAM sticks does it have? Does it have other cards?

I couldn't find a temp reading in the BIOS, I had looked into getting WinBond as a utilitiy to monitor things.

It's got 3 sticks of RAM, I pulled them and reseated them. It also has an AGP vid card and a modem and firewire cards in the PCI slots, I pulled and reseated them as well. I also reseated all power connections to the mobo.

[JustinSC]

You might want to take out everything but the videocard and one stick of RAM to see if that stablizes the system.

[dyazdani]

You might want to take out everything but the videocard and one stick of RAM to see if that stablizes the system.

That's a good idea, I'll try it out and post back. Thanks

[dyazdani]

You might want to take out everything but the videocard and one stick of RAM to see if that stablizes the system.

I took all the "extra" cards out of the machine - still no luck. I also put in the power supply from my machine and no luck.

I don't know what else to do. I hate to assume that it's the mobo without being able to check something, but my knowledge has reached the limit basically for this problem.

[Arneson]

I've found ocasionally a machine will recover from an inexplicable problem by pulling the battery out for a few minutes.
This resets all bios parameters to defaults.
It may help and it's easy.

[dyazdani]

I've found ocasionally a machine will recover from an inexplicable problem by pulling the battery out for a few minutes.
This resets all bios parameters to defaults.
It may help and it's easy.

I tried this already as well...no difference. Thanks though!

[Lex]

How many stories is your house? If 2 or more, you could try the bounce test. Drop from roof and see if it bounces. (Will require an extension cord to keep running for test. Be careful not to wrap around your ankle 2 times before dropping.

Drop the unit.

If it bounces, you know there is still life left in the old gal, if it splats, you will know it was a fatal issue anyway... Take the gold reclamation center, and do not pass go for 200.00. Go directly to Best Buy or Compusa for a new unit.

But seriously, this sounds like one of my problems. My PC has randomly rebooted at times. Typically, it's been related to either power supply or heat build up issue. But mine would not give me a windows shutdown screen, it would just reboot!

Replacing power supply, and restoring fan flow has fixed my issues.

The only other thing you could do in this case to eliminate possibilities is start offloading parts to another "good computer", and see if the "good computer" inherits the bad traits of bad computer. This is involving of course, as you can only replace 1 part at a time and do a full test to eliminate part as possibility. Very problematic way of doing things, but "could" isolate issue.


Since it is for someone else, you may want to just say hey, I've tried everything I know, and recommend you buy a new Apple. lol.

[dyazdani]

Yeah, that's where I'm at too, but I don't want to "infect" my PC with a bad part just in case something goes bad. Of course, that would be a way for me to get a new one!

The only thing I might do is take the RAM from my PC and try it, other than that, there's not much else I can do except switch the video card. I've already done the PS.

I would have already dropped it, but it isn't mine...

[JustinSC]

So this is what you've figured out from your tests:

1) It is not a windows problem (Can shutdown before it gets to windows)
2) It is not a Powersupply problem (tested with another PS)
3) Is not due to additional devices (tested with minimum RAM, CPU, etc.)

So that leaves the problem of CPU or motherboard. Do you have a way to test the temperature? You might want to try blowing an external fan (normal house fan) into the case while it is running.

I'm not sure how to test the motherboard besides trying another one with the same components.

[JustinSC]

Another thing you might want to try is taking the Motherboard out of the case and run it on a cardboard box (the M/B may be shorting on the case?).

[dyazdani]

So this is what you've figured out from your tests:

1) It is not a windows problem (Can shutdown before it gets to windows)
2) It is not a Powersupply problem (tested with another PS)
3) Is not due to additional devices (tested with minimum RAM, CPU, etc.)

So that leaves the problem of CPU or motherboard. Do you have a way to test the temperature? You might want to try blowing an external fan (normal house fan) into the case while it is running.

I'm not sure how to test the motherboard besides trying another one with the same components.

I don't think it's a temperature issue simply because it quits sometimes after only running 5-10 seconds, and all the cooling fans are working, plus I have the case open.

The CPU might be damaged though. I don't have another mobo to test and I don't really want to take my PC apart. I may give the cardboard a try.

[JustinSC]

I don't think it's a temperature issue simply because it quits sometimes after only running 5-10 seconds, and all the cooling fans are working, plus I have the case open.

The CPU might be damaged though. I don't have another mobo to test and I don't really want to take my PC apart. I may give the cardboard a try.

It is highly unlikely it is an overheating issue but it's still possible. Also the CPU can heat up extremely fast (burning temperatures in a second). Might make sure the heatsink fan has thermal paste and such.