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PC Shuts Down, waits, then Starts 6

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May 21, 2004
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I have a client's PC which apparently randomly shuts down completely, sits there for various times, some minutes, then starts up all on its own, without being touched at all.

The PC is just over a year old - just out of warranty! It is an Advent 3316 with a P4 3.06 533 processor. It ran fine for the first year. Then suddenly started this behaviour a week ago.

I have wiped its hard drive and reset the hard drive back to its original "as new" setup. I have replaced the PSU.

Can anyone think of any explanation other than the motherboard doing its own thing?
 
Thanks to Lemon13. Yes - I have checked the box, had it open, looked around while it was running. It is clean and appears normal. I replaced the PSU and had it open running for a couple of hours. Then I returned it to the client and asked him to check it out. The next day he said it had stopped again.

I plan to ask him to try using a different mains power cable and a different mains power wall socket. But these are long shots and unlikely to prove useful. They just provide cover while I do some more investigation - like this!

More ideas very welcome!
 
You may be on the right track concerning loss of main power. Most BIOS' now have a setting for action after AC power loss, such as STAY OFF or LAST STATE. If the BIOS in the PC in question has this, and it's set for last state, then if AC power is lost and sometime later restored, the PC will be powered back on.
 
Hook up a lamp to the same line, if it blinks, or goes dim, when the pc goes down, your user will see it, therefore your issue would be power.
If not, there could be tons of things happening....power supply relay, faulty motherboard core components, issues with an add-in pci card, or agp, etc...
Look to the board manufaturers troubleshooting FAQS first.
I seem to remember a board that had a faulty(leaking) component that caused this...a capacitor...
Look to see one on the board that is leaking, or is swelled, or both...use a magnifying glass and a flashlight...

I hear and I forget. I see and I remember. I do and I understand.
Confucius
 
Thanks for last 3 helpful suggestions! Any of these could be a solution. I have looked for viruses, and made sure that the AVG antivirus software - which I find very effective and cheap - is fully up to date.

The idea about a lamp is very practical and could be the sort of thing that the client would like to try.

The other hardware issues could be a sudden cause, but the PC has been running for a year without a problem. I would have to guess the motherboard as the most likely cause.
 
I also have an Advent 3517 which has just started a similar behaviour (shutting down completely at random after about 5-10 minutes operartion). The machine has not restarted automatically but after a short time it can start again without problem. Any thoughts?
 
Suddenly i start thinking about power save.....have you made ABSOLUTELY sure that power save is disabled both in the bios and windows?
The reason ask is because I get a ton of work orders for this type of issue and its mostly power save....like the newer dells need to have the button pressed to wake, not the keyboard or mouse, and users freak on that one......and the hibernation thing can really suck....I disable them all...

I hear and I forget. I see and I remember. I do and I understand.
Confucius
 
Thank you. I cannot recall checking this feature is disabled.

I may be able to suggest this possibility to the client. He has not contacted me for some weeks, so the PC may be OK now, or not...
 
Check it's not a 'wake on LAN' or 'wake on Modem' type setting causing it to sleep and wake seemingly randomly.
 
Keeping in mind that you have already changed the PSU.
1) a sticking or faulty reset/power button
2) power surge caused by:
poor connection (making and breaking) in the main power plugs, mains lead, wall socket etc.
3) lastly faulty motherboard

Martin

We like members to GIVE and not just TAKE.
Participate and help others.
 
I have now passed on these recent suggestions to our client and I await a progress report!
 
I've been bitten by a floating ground - Electricians love to grab a conduit ground or a water pipe. One of the laughs in the CDW "Fred in IT" book was one that an electrician grabbed ground on a drainpipe, and when someone flushed the wrong commode in the restroom, the server crashed. It may be time to have an electrician check that the mains and the grounds are all tight.

If you know or can find someone that has a Dranetz recording power line monitor, plug it in and leave it for a week or so and see if it's the power line.

Howard

 
2 months ago I had a brand new Dell Optiplex GX270 that was doing the same thing. It did not start this behavior until about a month after use. It would run a while, then shut down or reboot itself. It turned out to be bad memory. I replaced the memory and the pc has been fine ever since.
 
Are you sure it's not a heat issue? It was running fine with the covers off, but the problem returned when you put it back together and returned it to the customer. I would check your airflow and inspect the heatsink on the CPU.

Hope this helps.
 
Similar problem on Advent 3316. It just cuts out dead without warning, but can be rebooted after a few minutes rest. To add interest to life, it frequently whirrs to life from Standby without being asked. Could this be a wake on lan issue? The advanced BIOS controls came password-locked out of the box, so i can't tweak them.
Happy new year to one and all. John
 
There seems to be 100 ways to test the powersupply. Both in the wall socket and in the PC. The easy and obvious way to test this is to connect a different PC to the wall at the same socket that is used for the difficult PC. Connecting a lamp to the wall socket is not going to tell you anything. The glitch is likely to be to short to notice.

But if you have clients buying PCs from you, it can't be a big deal for you to get hold of a UPS. To my knowledge a UPS is a box that you can charge and that will provide great sinus waves even 5 mins after power is terminated.

Btw, have you been to your clients location? I had a PC that acted a bit like this once. At first we thought it had some connection with the tram lines outside in the street creating interference on the power grid. But it turned out to be a faulty soldering on the hard disc. Problems like these nearly always are related to soldering. Have you tried replacing the motherboard and discs?

It seems to puzzle you that it worked for a year before problems appeared. It does not puzzle me. It can be caused by many factors. Lightning (VERY COMMON), sudden glitches in power supply, dust between the processors fan and colling ribs, a weak soldering combined with any of the above can cause probs like this. I Norway where I live we have a law that says you can go back with stuff to the shop for 2 full years with anything electrical. It has proved quite efective cause many appliances have a tendency to break down after just over a years use.

Heres a quick run down of what I would have tried:
Connect a UPS between the PC and the wall.
Get hold of a new power cable.
Rip out all extension cards.
Put in a hard drive you know work.

IF need be: test all components in a controlled environment
Try the motherboard in a different cabinet.

I assume you have done al this, so when you are sure everything works theres only incompatibility issues and soldering issues left. Now, incompatibility does in general not take a year to show up, so its likely tyo be the latter. But remember, putting the motherboard into another cabinet is not going to tell you anything if you just leave it there. You'll have to find some way to stress it. Try some extensive benchmarking.... Btw, have you asked what your client was doing at the exact time of the crashes.

Furthermore I am not too surprised by the fact that it turns it self back on again. If its a faulty soldering, this is quite normal. Think about it.... as it gets warm it looses connection... whats to say it can't regain that conn after it gets cold again? Most my computers boot when I turn the power on....

Suggestions for further inquiries:
Move the PC around the house to make sure theres no interference problems.
Try a different house with different powergrid.
Find out what PC is used for when it crashes.

If this is a one year old PC it should have temperature section in the bios. If this is ok, you can assume that processor heat is not the cause. But thats not to say the problem is not in the processor.
 
sixstrings said:
Are you sure it's not a heat issue? It was running fine with the covers off, but the problem returned when you put it back together and returned it to the customer. I would check your airflow and inspect the heatsink on the CPU.

I would suggest you check that one out first as its a common situation for a pc to work fine with the cover off and then heat up with the cover on. YOu didnt mention anything about fannage inside the case. At least you could pinpoint the problem or eliminate the heat issue as the prob.
After the heat issue, i would suggest that the bios holds the clue. There is some setting in the bios that the system is using to shut down. These settings have been discussed by others so i wont go there except that some mobos have a feature that turns the pc off if the temp gets too high, seen most often with amd cpu's but still a possibility.

Windows will shut down on some errors if it is set up to do so, but i dont know if that is the cause as the pc in question boots up again later.







Good advice + great people = tek-tips
 
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