another computer problem

[cadpro]

Ok, I consider myself pretty computer savy, but this one has me miffed. Last week (on Thanksgiving of all days... ), my computer started acting psycho. Long-story-short, my computer (DELL) keeps shutting itself off, then restarting itself. Basically, you can use the computer for 15 minutes, and then it shuts itself down; once it does this, a few seconds go by, and then it turns itself back on, does its normal start up, and once it gets to the screen where you select the user, it shuts itself off again . It goes through this viscous cycle, each time, it going less and less in its start-up procedure. The only way I can prevent this is to unplug the computer from power.

Is this a fan/cooling issue on the CPU? or this is power supply (again, is it heat related?) issue? The fan on this computer is(was) so quite before, I can't say whether or not it is on.
Please help!

[TonyL]

You've got a bad mother board. this happend to us a week ago. at work.

Has it given you the "THERMAL EVENT" warning yet?

If not, prop a fan up near the intake on the back of the computer, and blow some air in there, then fire it up. If it stays on, it's a power supply/fan problem. If not you may have a cruddy motherboard. Try blowing it off with canned air.

If none of that helps, your mother board is screwed. (likely) and you need a new one. Hope you got the service plan!
good luck.

[BA.]

I mostly agree with TonyL here.

It does sound heat related to me. (thermal event)

Using a fan is the primary way to see if it's heat related. Usually, instead of placing it in front of an air intake, people will just take off the side of the computer and blow the fan directly on the entire motherboard.
The two chief culprits of heat-related issues are the video card and the CPU.


There are several neat and small temperature displaying programs out there.
One of the most common ones is "Motherboard Monitor 5". aka MBM5. Free download.

Depending upon the age and the system, your motherboard might still be just fine but the CPU's heatsink might just need new 'thermal grease' between it and the top of the CPU.
What CPU do you have?

Something else you really should do is BLOW THE DUST OUT OF THE CASE AND MOTHERBOARD. Personally, I use an air compressor. Systems that sit on the ground as opposed to the desk are more susceptible to collecting dust. Also, having pets creates hairs clogging up the fans and air flow.
Be sure to power the system off before blowing it out. And, hit the CPU heatsink and all fans, and the intake and exit of the Power supply really well.

[JoshStratton]

Just a thought. Are you running virus protection? There was a virus going around a few years back that would restart your machine. I highly doubt that is it, but worth a look before spending a couple hundred bucks on parts.

[cadpro]

Thanks for the tips. This is pretty new Dell (Feb 06), and its got a huge heat-sink enclosed in shroud, with a big fan. Took the cover off last night, there's a little bit of dust, but nothing major. Both fans are working as well. I put a high cfm fan blowing in on the unit (with cover off), and it seemed to help, but it still did the same thing.

Also, there is another good sized heat-sink on the mother board, that doesn't appear to be "over" anything; its just by itself. Its black, about 1.5" square, and it gets extremely warm to the touch when the computer is on. Any idea what this is? I'll try and take some photos later.

Thanks again!

[TonyL]

Sounds A LOT like our motherboard problem, only you aren't getting the "shutting down due to thermal event" message. I'd call dell. That heat sink you are describing sounds like the one for the video chip. It's supposed to be hot.

Have you tried running in safe mode?

[JoshStratton]

Also, there is another good sized heat-sink on the mother board, that doesn't appear to be "over" anything; its just by itself. Its black, about 1.5" square, and it gets extremely warm to the touch when the computer is on. Any idea what this is? I'll try and take some photos later.

Its been a while since I have built a PC, so I may be out of touch a bit, but that sounds like the fan that cools off the processor. I bet your processor is under/inside it.

[shep]

A blue screen in windows XP will do the same thing. If you can get into a desktop right click on my computer go to properties click the advanced tab click the start up and recovery button uncheck the automatically restart box, click apply and OK, close the properties window. If it is blue screening it will not reboot now and you will be able to see the error. I agree with the above suggestions, also you can hold a peice of paper behind the PC to see air flow. The power supply should be blowing out and the cooling fan for the heatsink should be sucking in.

[BA.]

good point Shep.

Also, agreed on the other heatsink. It's either for an on-board video GPU or it is the motherboard Northbridge. (if i remember correctly)

Since it's a newer unit, you can obviously disregard my comments above about the dust.


Have ya added or changed anything since it was new?

[cadpro]

Have ya added or changed anything since it was new?

nope... unlike all my other toys, she's bone stock!