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View Full Version : Computer Shuts down Randomly


terryriv
09-21-2009, 08:36 PM
I'm having an issue with a clients computer. We have tried a couple of power supplies, have looked at all of the fans. Tested the Hard Drive, and checked voltages.

This person has Windows Vista running on a non-Brand Name Tower. It will randomly just shut down. You can immediately turn it back on and it may run for mins, hours, or days before doing it again. There is nothing in the eventlog other than the previous shutdown was unexpected, and it doesn't blue screen.


This has me stumped.. any input would be appreciated..

Doctor Micro
09-21-2009, 08:58 PM
If this is at the customers's location, I'd immediatly suspect voltage instability and fluctuations, possibly caused by poor service from the utility company, faulty wiring, heavy loads on the same circuit or a combination of the aforementioned. You can buy a cheap outlet tester that can check for wiring faults. Check to see if window air conditioners or other appliances are on the same circuit. You can also have the utility company come out to check service to the location, though they probably won't do anything unless they find an obvious easily-fixable fault on their end.

terryriv
09-21-2009, 11:42 PM
If this is at the customers's location, I'd immediatly suspect voltage instability and fluctuations, possibly caused by poor service from the utility company, faulty wiring, heavy loads on the same circuit or a combination of the aforementioned. You can buy a cheap outlet tester that can check for wiring faults. Check to see if window air conditioners or other appliances are on the same circuit. You can also have the utility company come out to check service to the location, though they probably won't do anything unless they find an obvious easily-fixable fault on their end.

I was thinking in that direction. I did use an outlet tester to make sure the wiring was ok, but I was thinking next of taking over a UPS and see if that helps.

Strange part is that there is another computer that is just around the corner on the same circuit and that one stays on.

Doctor Micro
09-22-2009, 02:04 AM
I was thinking in that direction. I did use an outlet tester to make sure the wiring was ok, but I was thinking next of taking over a UPS and see if that helps.

Strange part is that there is another computer that is just around the corner on the same circuit and that one stays on.

Unless the other computer is identical in composition, construct, components and age to the one that randomly reboots, it's really not a fair comparison.

You haven't really done a proper diagnostic, or at least you haven't mentioned other, more obvious steps you should have taken.

Have you tested the memory? How about a heat issues with the CPU, perhaps thermal paste that has gone bad? What about faulty cards, like video, audio, usb, etc etc?

Sure, any of those issues could be present also and they're certainly worth checking, but it was the unpredictability and wide variability in run times with the reported randomness of the reboots that sounded a whole lot more like power problems to me. At any rate, I'll be interested to see what happens when he plugs it into a UPS. Betcha a beer. :)

terryriv
09-22-2009, 07:17 AM
You haven't really done a proper diagnostic, or at least you haven't mentioned other, more obvious steps you should have taken.

Have you tested the memory? How about a heat issues with the CPU, perhaps thermal paste that has gone bad? What about faulty cards, like video, audio, usb, etc etc?

Memory has been tested, but didn't see that as an issue as the computer doesn't restart it just turns off. I did check all the fans, and I ran speedfan with a log to check the temps and power changes, and all seems to be within tolerances.

Wed. I have to go back over there and connect the UPS, I will post my results. The strange part is that it may shut off several times a day, or it may go for a week without doing it, and this PC is on 24/7.

studiot
09-22-2009, 09:25 AM
This thread is classic.

Instead of each post narrowing down possibilities, each one greatly widens their scope.

That is because, despite older and more experienced heads imploring OPs to include full (relevant) details, this information is arriving in dribs and drabs.

I did use an outlet tester

Have you, for instance, taken the even more elementary step of changing the power lead?

If you simply plug a UPS into a dodgy lead and then a new temporary one into the pc you will be no further forward.

Is it not possible to temporarily relocate the pc, preferably to your workshop?

DanF
09-22-2009, 09:32 AM
I had a similar issue some weeks ago, and it ended up being a dodgy power cable. Fortunately enough it was easy for me to notice this as the client told me it happens when they move something... which results in moving the cabling and disconnects the system from power.

I'm not saying it's the same for you or that you suck at diagnosing (non of this)... but my 2c :)

JAY
09-22-2009, 12:56 PM
I had a simliar problem with an acer laptop, sometimes it would run all day, other times it would last seconds, all the obvious tests came back with no clues. I decided to reseat the RAM and ever since it's been fine!

terryriv
09-22-2009, 02:27 PM
Have you, for instance, taken the even more elementary step of changing the power lead?


Is it not possible to temporarily relocate the pc, preferably to your workshop?

The cable was changed when I first started looking at the machine, and it fits nice and tight.

Also it is not possible to move the machine to my shop as they use it on a daily basis, and the last time I was there and tried stuff on it the computer didn't shut off once for 10 days.

Cue
09-22-2009, 03:18 PM
As this is a custom made computer, can it be that the motherboard has bean badly or some how wrongly sheeted in the tower?
Perhaps there is some part of the motherboards contact touching the towers metal body and the fluctuations are when the tower gets static?

I know this is a very long shot, but I thing it has come to that :)
Good luck with your problem!

Doctor Micro
09-22-2009, 05:17 PM
Dang... sometimes it runs for as long as ten days? That being the case, how long will you wait after you put it on the UPS before you deem it fixed? (obviously, if it still shuts down unexpectedly before then even with the UPS, we're going to hear about it in here, I'm assuming).

Just as an afterthought (brainstorming here), is there any remote admin or monitoring software installed on this machine? Does the NIC support Wake on Lan and is that feature implemented? Is there a possibility of a remote shutdown script being executed from another machine on the network... maybe something left behind by another tech and one of the end users clicks on it once in a while just to see what the icon does? Are Automatic Updates on or off? Lastly, have you checked the event logs to see what happened right before the shutdown?

Don't forget, ACG and I have a beer riding on this one... :)

studiot
09-22-2009, 06:38 PM
OK so it's not the cable.

You didn't fully describe the shutdown mode, but apparently Windows has time to write something in the log?

This is important as the pc cannot be subject to sudden power disconnection of more than about 200 milliseconds.

Are there any times of day or night (you said 24/7) that it does or does not shut down. And can you tie this in with external events?

K007
09-22-2009, 08:04 PM
You haven't really done a proper diagnostic, or at least you haven't mentioned other, more obvious steps you should have taken.

Have you tested the memory? How about a heat issues with the CPU, perhaps thermal paste that has gone bad? What about faulty cards, like video, audio, usb, etc etc?

+1 Faulty cards.
I wish there was a betting option on this forum.
I would put down 50 dollars is one of the resons ACG mentioned.

tigertoes
09-22-2009, 10:15 PM
I say faulty card also, I have in the past had faulty graphics card of alll things causing the issue. Good Luck :)

terryriv
09-22-2009, 10:20 PM
OK so it's not the cable.

You didn't fully describe the shutdown mode, but apparently Windows has time to write something in the log?

This is important as the pc cannot be subject to sudden power disconnection of more than about 200 milliseconds.

Are there any times of day or night (you said 24/7) that it does or does not shut down. And can you tie this in with external events?

It's really not that the computer shuts down, it more that it just shuts off or drops power. One moment the user is working on the computer and all of the sudden black screen and the computer is off. She just reaches down hits the power button and it starts booting up.

It happens mostly in working hours although a couple of times it has happened in the middle of the night. So I have tried to tie with something going on in the office, but no such luck.

As for the previous post by Doctor Micro, I am already hearing about it. :eek:

The logs before it goes out doesn't really show any warning or errors, and the wake on Lan and all of that are turned off.

The 10 day period is the longest it has went, but usually the machine does this about every couple of days. When it does happen it usually with happen about 2 - 3 times that day, and then skip a couple of days and do it again.

Doctor Micro
09-22-2009, 10:26 PM
All those hard shutdowns can't be doing it any good...

studiot
09-23-2009, 01:03 AM
At this point I would be suggesting a temporary replacement pc (I keep some courtesy pcs) to take the offender away for interrogation in the workshop.

It must be worth it to the owner.

Larry Sabo
09-23-2009, 01:04 AM
At this point, I usually throw it against the wall a few times until there's something I can point to as definitely broken (and uneconomic to fix). :D

terryriv
09-25-2009, 01:08 PM
The Score is Bad computer 1 Tech 0...

Put the UPS on the system, and did a extended memory test with Goldmem. Memory came out good, but the following day the computer shutdown.

I guess it's time to grab the machine as the only thing left is the board and CPU.

Doctor Micro
09-25-2009, 01:59 PM
Beer: ACG 1, Doc 0 :)

Galdorf
09-25-2009, 02:26 PM
I see this problem all the time it is one of 5 things:

Bad capacitor they don't need to be leaking or puffed up at the top they can also blow out the bottom ,it's rare but it can happen or even on verge of drying out can cause intermittent power loss.

On some motherboards there are caps under the stock heatsink if you do not remove you cannot see them at all.

Cpu/heatsink contact sometimes pulling off the fan/heatsink and removing the cpu cleaning off the heatsink pads and putting on arctic silver will do the trick.

Failing chipset or chipset overheating most techs overlook the chipset heatsink i have seen machines hit by power surges from lightning storms that damage the chipset through the lan port.

Overheating/bad video card caps can blow on video cards as well it can cause all sorts of problems as well as seized cooling fans.

Windows software problem/ bad drivers bad drivers or mismatched versions of dll's can do this also sometimes the machine shutsdown or restarts disable restart on error and you will see a blue screen, i use blue screenview to track down the problem system files.

studiot
09-25-2009, 02:39 PM
Windows software problem/ bad drivers

Yes we haven't discussed this possibility.

It is certainly worth soak testing to see if it still happens in safe mode, linux and bios.

Doctor Micro
09-25-2009, 02:43 PM
@Galdorf: Do you also see other symptoms besides just a shutdown with nothing showing up in the event logs?

Galdorf
09-25-2009, 03:18 PM
With cap problems yes , i just replaced a customers mb everything else was from original build it had a bad cap that was dried out, the machine would just randomly shut off with no errors or blue screens nothing in logs.

terryriv
09-29-2009, 03:20 AM
No. Check the video card, network card(if any), and check the other devices. Unplug them one by one and test. Also, as mentioned, test it with linux or in the bios. Just let it run, and see what the deal is.

The network and video are onboard, and there are no other devices plugged in. It's an AM2 motherboard, so I figure I will grab the computer Friday morning and try to stress it out in our shop.

terryriv
10-17-2009, 03:01 AM
Well it has been 2 weeks since I changed the motherboard out on this machine for a new one with the same CPU and haven't had any random shutdowns.

Thanks all for the help..

ComputerClinic
10-17-2009, 07:22 PM
This might not do anything but it might be a good idea to completely disassemble the computer and reassemble it, re-applying thermal paste and everything. Also, if possible, replace all add-on cards with known working ones. If it goes a couple weeks without shutting down, replace a card with the old one. Do this until all cards are back to normal and its working or until it stops working and you know what card is causing the problem.

PcTestCard.com
10-22-2009, 07:22 AM
Check the CPU temperature, the RAM and if there is any damaged capacitors on the mainboard.

Hope this helps!
Bill

basic
10-22-2009, 09:26 AM
He's already fixed the problem.