Old desktop not POST-ing(no beep when turned on and no display)

[xxepicboy75xx]

My old desktop didn't POST today. There was no display output and the HDD activity light remained off. It worked fine a couple of days ago, any suggestions on what to do?

Asus M2NPV Motherboard
AMD Athlon CPU
4GB RAM
Video card w/sound card installed in 2 PCI slots.
Thanks in advance

UPDATE: After much struggle I decided to pull out the CMOS battery and wait 30 seconds....and it worked! Everything is great now. Thanks for ur support.

 

[King_V]

If nothing at all powered up (optical drive, didn't hear the HDD spin up, no fans going), then my first instinct would be to check if the power cord didn't come loose, if the 120v/220v switch is still in the correct position, or maybe if there's a fuse in the PSU that has blown.

 

[xxepicboy75xx]

The Mobo LED light is glowing green, so it has to have power. All the CD drives/periferals are getting power. I tried unplugging the 2 CD drives but to no avail. The power supply is set to 110. It was working fine 2 days ago so have no clue.