I'm using a P4 system with an Intel chipset which worked fine for about 6yrs until recently it stopped to switch on.

The symptoms are that, when ever i power up my PC, the LED on the motherboard is glowing bright but the SMPS FAN and the fan on the processor are rotating for about 3 secs and then coming to a halt, the mouse, monitor, keyboard are getting their power but the monitor is blank all the time. I don't think tat neither of the HDD (IDE), the DVD drive, the floppy drive are being powered up. I'm not able to access the BIOS too. Also i hear a buzzing noise from the PC.

I would like to know how i can FIX this problem. I am not certain but it sounds like your PSU is on its way out.The buzzy noise is probably coming from your PSU, where something probably is wrong. If you got one, TAKE another PSU and TEST on your computer. If it solves the problem, you can either use it or purchase a new one.

Also, is your computer shutting down afterwards? or is it just turned on without any progress?Sometimes the pc's turning off immediately And sometimes it's not.. But as i said, the processor fan and smps fan stop rotating almost after 3secs after i hit the power button to start my pc.. And the led on the board's always glowing.. But the drives r not gettin their power..