The PC doesn't power on

[danish.hanna]

I have a Dell precision T7400. It have a problem that some times works and when it turn on after some minutes the fans will rotates in maximum speed, display will gone, I need to power off it by remove the plug, now it doesn't turn on now, the LED on motherboard is lighted but no responds on power botton.

 

[dontlistentome]

No power? First, I'd look inside the computer, to see if anything has come loose. I once found a loose 24 pin ATX power cable in a computer that wouldn't boot up. I don't know if it worked itself loose or if someone simply didn't seat it correctly, but once I connected it properly it worked fine. Check the memory sticks too.

Second, I'd suspect the power supply is dead. Maybe you can test the power supply in another computer, or try another power supply in this computer.