<p>since this morning, my computer quasi- shuts off after it’s turned on for 5-20 minutes. by quasi, i mean that the harddrive still seems to be running, the CPU light stays on (without blinking), and the CPU fan stops dead. nothing responds so I am forced to shut it off.</p>
<p>i have ruled out virus, because i have anti-virus programs, and because I just formatted my harddrive, but when i re-install winXP the same problem occur in the middle of the installation.</p>
<p>right now i am suspecting the motherboard to be at fault. anyone has a clue to what is going on? thanks in advance.</p>
<p>Need the following information about your system:</p>
<ul>
<li>How old is it?</li>
<li>Does the monitor suddenly goes blank after 5-20 minutes?</li>
<li>Is your power switch light still on?</li>
<li>Does your hard drive access light flash occasionally?</li>
<li>How do you know if the CPU fan has stopped?</li>
<li>Have you added any new video or sound cards to your system?</li>
<li>When your system shuts down, can you re-start your system immediately or do you have to wait for some period of time before everything starts working again?</li>
<li>When your system goes dark, reach behind your desktop and see if you can feel the power supply exhaust fan working. If the fan isn’t working, you need a new power supply.</li>
<li>If the power supply fan is still running, it might be your processor or the motherboard. If the CPU cooling fan stopped, your processor may have reached a pre-determined temperature which forces the system to shut down.</li>
</ul>
<ul>
<li>How old is it?
2 years</li>
<li>Does the monitor suddenly goes blank after 5-20 minutes?
yes. basically the computer is shut off, except that somethings are still running</li>
<li>Is your power switch light still on?
yes</li>
<li>Does your hard drive access light flash occasionally?
nope. it stays lighted</li>
<li>How do you know if the CPU fan has stopped?
we opened up the computer :)</li>
<li>Have you added any new video or sound cards to your system?
yes, but the video card has been working fine for about 6 months now.</li>
<li>When your system shuts down, can you re-start your system immediately or do you have to wait for some period of time before everything starts working again?
yes, i can restart immediately</li>
<li>When your system goes dark, reach behind your desktop and see if you can feel the power supply exhaust fan working. If the fan isn’t working, you need a new power supply.
the exhaust fan is working</li>
<li>If the power supply fan is still running, it might be your processor or the motherboard. If the CPU cooling fan stopped, your processor may have reached a pre-determined temperature which forces the system to shut down.
i think it has nothing to do with temperature, because the fan shuts down simultaneously with the computer, and when i checked the interior of the computer doesn’t seem to be hot at all (also no funny smell either)</li>
</ul>
<p>hmm, should i just toss out the motherboard? thanks a lot for your time</p>
<p>If your machine completely locks up, it might possibly be a ram chip. Doubtful, but it might be worth checking out.</p>
<p>Probably a good call to try a different motherboard though - might shut down all cpu and expansion slots if the cpu fan speed suddenly drops to 0.</p>
<p>Is this a Dell computer? I’ve known them to do things like that. If it is a Dell, I’d make a guess that the warranty expired within the past month or so?</p>
<ul>
<li> RAM.<br></li>
<li> Monitor</li>
<li> CPU cooling fan</li>
<li> Power supply</li>
</ul>
<p>You can rule out a total power supply failure, as the drive light would go out, but one or more rails (the term used for seperate voltages put out by the PS) could be failing.</p>
<p>In general, failures like this are almost always due to a component heating up. They don’t need to overheat, just heat enough to act up (think of expansion with heat that opens up a tiny crack in an electrical joint…) so you would normally not smell anything. Indeed if it did smell, you’d have an easier time troubleshooting.</p>
<p>Unfortunately, the best way to check these things is by substitution.</p>
<p>It is very unlikely to be the BIOS. I would not spend time on a BIOS upgrade. Rather, I’d use those precious minutes before lockup to back up critical files. Remember that you are at great risk of a trashed HDD if the lockup occurs during a critical disk operation. BTW, if lockup occurred during a BIOS upgrade, you then made an expensive wall decoration - your motherboard would be useless (OK, a few manufacturers have protections from this but not most, and few retail…)</p>
<p>Could be the video card. Mine did the same thing. I added a fan to cool off the video, and no more problems. Also, are you running something graphics heavy when this happens?</p>
<p>Your comment about tossing out the motherboard makes me think that this may be a home built system.</p>
<p>I need to know the following:</p>
<ul>
<li>Is this a home brew system?</li>
<li>What kind of processor did you install?</li>
<li>Did the processor come already installed with a CPU cooling fan or did you install the fan separately?</li>
<li>Reading from the Power Supply label, who manufactured the PS and what is its wattage rating?</li>
<li>What kind of video card did you install?</li>
<li>As a test, remove the video card from your system and plug your monitor into the video connection on your motherboard. Does the computer still shut down?</li>
</ul>
<p>thanks for all your help. but i think it’s probably easier to just go buy a new computer. here is one more “noob” question, though: how would the release of windows Vista affect the price of high end computers? maybe more people would need to update their hardware in order to install vista, thereby increasing the demand and cost of the already expensive high-end PCs?</p>
<p>For Vista ready computers, you need to have a good video card and enough memory to run most Vista features. </p>
<p>Frankly, your two year old machine should be good enough to run it. Spending money on a new computer seems wasteful until you determine what is causing you problems on your current machine. It could be a failing power supply or a bad CPU fan…</p>
<p>Eh, actually, you don’t need a great graphics card. A integrated GMA 950 will run vista with areo no problems. 512MB of ram will be a must, though.</p>
<p>High end computers are currently more than capable of running vista, as are most consumer systems. It won’t change anything.</p>
<p>Also, the problem still sounds like power supply to me. Usually cooked motherboards are pretty obvious. And a new power supply is what, $70 at compusa…way cheaper than $700 for a new dell desktop (gag). </p>
<p>What is it about macs you don’t like? I’m just curious as I use both.</p>
<p>well, my friend has seven mac laptops. each one of them freezes about once per hour. also, the mouse just isn’t a mouse with one button to click</p>
<p>my strong guess is that it’s the cpu fan - a very cheap and easy repair. All you need is a screwdriver and a new fan - can be bought for a few bucks at CompUsa or Radio Shack. If fan isn’t working properly, sensor tells computer that chip is overheating and computer shuts down to preserve chip. You wouldn’t feel the heat in the box - it’s the chip that overheats. Also, if you smelled something, the chip would already be fried - that’s why the machine shuts down, to prevent this.</p>