power failure

By NocRaz ·
Ok, this is dumb coming from someone who's been working on computers for over 10 years.

I am working on a system that keeps rebooting itself. It actually turns itself off as if someone were hitting the reset button on the front of it. It especially does it when it has a load on it. By load I mean downloading something from the internet, or moving files via network. Now, the guy who built the system (I will refrain from name calling here) swears its the video card and that it just needs to be taken out and cleaned. Now logically, that makes absolutely NO SENSE! But, just to please the boss, I took the stupid video card out and cleaned it and guess what... the computer's little ghost friend is still rebooting it! So my natural reaction to the problem was, power supply.

My question is, is there any other possible cause of this computer rebooting itself other than the power supply (I don't wanna replace it.)

I'm not sure about this system anyways becuase of the way it was supposedly built. I have no idea if all of these are used parts out of here. so I have no idea if any of this is reliable. God I hate fixing **** after other people have screwed it up.

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Safe mode with Networking

by sgt_shultz In reply to power failure

sounds like a reproducible problem. which means it is fixable. my first test would be get the thing to reboot (you say while downloading big files, for example) then try to reproduce the failure in Safe Mode with Networking. That'll tell you whether you have a hardware or software problem. i would also turn off system restore and scan the thing with updated antivirus and spyware cleaner. i love fixing stuff others have worked on. it is how i make my living...

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Things that go wrong.....

by JamesRL In reply to power failure

Not trying to rub anything in, but this is why some companies like mine spend more money and buy good servers like IBMs. If I had the same scenario with an IBM server the bios would be monitoring these events and I would get a warning light inside the box showing me what component failed.

Having said that, there are a number of reasons for periodic reboots, especially under load.

A flaky PS could generate excess heat or fail to provide enough power at peak demand, causing a failure.

It could be a dead fan, either on the case or the CPU (or in the PSU). Try running it with the case open to see if the fans turn properly. Also see if they speed up under load - most modern motherboards have a temperature sensitive fan controller.

I've had reboots because of Video cards, but you usually get some warning first - some artifacts on the screen.

A good first step would be to take the server apart and clean out all the fans, get the dust off all the components (dust traps heat) and put it back together again.

You could try swapping out a new power supply if that helps. You might also want to see how much power it can handle versus the load - how many disks it drives etc.

Replacing power supplies on most computers is fairly easy, and power supplies are not that expensive, compared to the time it takes to diagnose a problem. I would rather spend $50 to eliminate one potential source of problems than to spend another hour wondering if its the power supply.


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by NocRaz In reply to Things that go wrong.....

I just wanted to say thanks to all of you. Hopefully one of these solutions will work versus me replacing the power supply! I have to work around my boss and the secretary considering there are things on this computer they need, and won't let me put the other hdd in the new computer that works just fine... I have to keep this computer running until they get done... highly irritating.

And James, this is such a small company that buying all new stuff would be out of the question, but using old and used parts should be also..... thats also against my better judgement.

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Load implies heat.

by TonytheTiger In reply to power failure

In addition to failed fans mentioned, look at the capacitors on the motherboard. Especially the larger ones near the CPU and memory sockets. I have seen a lot of these lately (a lot means literally in the dozens!), in different brands of computers. You may be replacing a motherboard. But even then, it could have been the power supply that caused the problem, so if you end up replacing the motherboard, replace the power supply too.

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Right assumption.

by fungus-among-us In reply to power failure

I too would look to the Power Supply first. Random reboot and shutdowns without error messages are commonly power regulation issues. I'd load some sort of system monitoring program (mbm or speedfan) and keep an eye on the 3.3, 5 and 12v rails. Also keep an close watch on the CPU Vcore voltage as well as the voltage applied to the videocard. Go ahead and stress test the system and look for out of range fluctuations, also keep a watchful eye on all of your temps.

Good Luck

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looking closer at CPU

by jdclyde In reply to Right assumption.

Look in your BIOS for what the temp setting is to protect the CPU. Most BIOS have a selectable temperature that your system will shut down at. Change this and give it a run. Depending on they type of processor you have, will depend on what the "safe zone" is.

Also **** out the system to make sure all fans are clean and running. dust on the motherboard will hold heat in.

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after power failure

by johnav In reply to power failure

I am having the same problem. The first time it happened, I booted from a Win XP cd. I went into the "Repair" mode and ran CHKDSK. This found an error with one of the system files. I don't remember if i had to copy the "bad" file from the XP CD or if the scan repaired it. Afterwards the PC would reboot normally.

It happened again, but the second time, running CHKDSK indicated that there were multiple errors and CHKDSK could not run. I ended up re-formatting the disk and I am going to re-install windows etc tonight.

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Examine the motherboard.

by 1bn0 In reply to power failure

The symptom you describe can also be cause by failed capacitors on the mother board.

Check the top of the larger capacitors for bulging or splitting. They should be flat not convex.

And yes, some machines will boot with this problem and then once the load increases they reboot just like someone had hit the reset button.

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I had this before, was bad firmware on mobo

by Slayer_ In reply to power failure

Basically my mobo wasn't providing enough power to my CPU, causing it to restart. The firmware also interestingly wouldn't allow to be updated, so the board was faulty.

With a new board I was fine.

The video card failures also caused it to reboot endlessly, it might get going, it could sit for days, or just randomly shut off, even if I wasn't doing anything CPU intensive.

nVidia cards seem to have a high defective rate when I was trying to get my system rebuilt, was really anouying.

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