Hello, I have a Windows XP desktop. One day I came home to find that the moniter was black, but the tower was still on and the fans were going top speed. After waiting a very long time I unplugged the computer and tried to reboot it. It loaded up normally, but within a few minutes it just shut itself off again. When I tried to turn it on it just starts spinning the fans, and then something clicks and it retrys. It keeps this up for a few minutes and then just stops. I have tried over and over and a few times the fans have kept going, but the moniter stays black and the computer responds to nothing.
I know this was long, but I am at a loss on what to do.
-- Accumulated dust can cause the CPU to overheat, which would shut down the computer. Solution: Open the case side panel and visually inspect. If you find a lot of dust, you could use canned air to blow it out. Especially clear dust from around the fans and the CPU heatsink.
-- The power supply may be failing - not supplying the required current to the motherboard. Solution: Put the power supply on a multimeter to check voltages or replace with a new (or known to be working) power supply.
-- The monitor or the rear panel video output may be failing. Solution: Try a known to be working monitor.