Boots fine (mostly), then dies

[CEJ]

Hi:

I have a weird problem with my laptop. It's a 3-4 year old Dell Inspiron 8500. Basically, when I turn it on, it boots fine, loads up XP pro, I can login and work on it for 1-2 minutes. After 1-2 minutes, the display slowly starts to decay (these colored dots start appearing on the screen, the screen starts flashing every few seconds, and then it just basically freezes). This also happens if I boot into the bios menu and let it sit for a couple of minutes (so it's not a hard drive problem). If I try to restart it immediately after this, I just get a screen with a flashing cursor (sometimes this screen has these very odd lines running from top to bottom and left to right on it) and nothing happens. I have to let it sit for at least 15 minutes before trying again, after which it boots fine as before and the problem starts all over again.
I'm thinking either motherboard, or graphics card, maybe the lcd screen. It's out of warranty, so I'm probably not going to pay to replace parts on such an old computer, but I thought I'd see if anyone has any other ideas.

Thanks in advance,
-CEJ

[briansmall]

Very possibly a bad fan or cooling system. circuity is warming up and causing the failure. You will have (or have someone) get into the insides to find this problem.

[CEJ]

I opened it up, there was a lot of dust around the fans, but I didn't see much else wrong. Anything special to look for?

-CEJ

[jimbojone]

it would be best to take the laptop apart, (just the bottom) and blow the crap out of the heatsync, and fans. also ensure that all the fans are functioning. i've seen this problem alot, because laptops tend to have very poor ventilation, and the heatsync's get gummed up pretty good with dust, gunk, etc. etc.

[briansmall]

I opened it up, there was a lot of dust around the fans, but I didn't see much else wrong. Anything special to look for?

-CEJ

Well, it's open, so blow out the dust.

Listening for the fan, or feeling where the air exits is the way to tell that it is working. Also, placing your hand on the case in the general area of the cpu will tell you a lot. If it's pretty darned hot it probably has a problem. Then again, the case won't get all that hot if the machine isn't on long enough. But the cpu can overheat in as little as a few seconds, or take as long as a few minutes depending on the heat sink.

If you hear the fan and feel its flow, then that's probably not your problem.

It could also be a bad memory chip heating up and failing. If you have two of them in the machine, try them one at a time (being aware that if you use one chip it probably needs to be in the "A" slot) .. If you do not have a second chip, it would be good if you could find a known-good one to swap out with yours in order to test it. Any size would be okay, but it has to be of the same family and at least as fast as the one you now have. (Faster is generally okay, slower generally is not.)