by going to this page and checking the "Troubleshooting Steps" listed for your computer:
There is good info here and Dell has good customer support. After following their troubleshooting guide, if you still cannot find the problem, come back for more help.
I have a Dell Dimension 8400 PC. I recently had some trouble with some spyware and viruses, but with the help of a great forum, I was able to clean it up and it has been running literally like it did when it was new for a couple of months since. A couple of nights ago, it just quit, all of the sudden. Just shut down like the plug had been pulled. I noticed the power button was flashing yellow. I pushed the power button, but nothing happened. I HELD the power button and the yellow light stopped flashing. I was then able to reboot normally.
After a few minutes it quit again. Once again, I held the power button until the yellow light stopped flashing and again was able to reboot normally. This time it ran fine the rest of the evening.
Then, last night, it had been on uninterupted since the night before, but after trying to watch a DVD, it quit again. This time when it rebooted, it quit after a few minutes, and then after another reboot it ran less time, and then finally, it wouldn't even completely boot up before quitting.
I let it sit overnight and tonight I booted it up again and it ran fine for about 5 minutes but once again quit and with each reboot ran less and less time.
Is the power unit in the cabinett going bad? What could be causing this? When it does boot up fully, everything seems completely normal until without warning it just QUITS, like you unplugged it.
Any help would be appreciated.