Mystery Boot Problem (PSU?)

[flakjack]

I've had quite some experience building computers over the years and this one has got me stumped.

My current rig had an unexpected death last week. On booting, the power lights were illuminated, the fans were spinning up but i'm getting no output and there was no PC speaker beep. I tried another display just to rule the monitor out and concluded that the mobo had gone.

I've since replaced the mobo and got a package deal from Maplin with a new processor, chip and 4GB DDR. I've installed the new components (doubled checked everything) and am still getting no output and no boot beep, however the motherboard lights are showing green and I've double checked the PSU leads are plugged in correctly.

The problem did seem to arise the day after i'd turned the PC off at the power supply for the first time in a good 2 years so i'm wondering if for some reason the PSU is only partially working as I'm stumped what else it can be.

PC:

MOBO: ASUS F1A55-M LE
PROCESSOR: AMD APU A4 3300 DUALCORE
RAM: 4GB 1333MHZ DD3
HDD: 500 GB Seagate SATA II HDD
500W ATX COOLERMASTER PSU

I've always found that sharing problems is the best way to solve them, so anyone who can share some knowledge will be todays hero.

Cheers!

 

[flakjack]

Scratch the above, checked the PSU out on a friend's PC and boots no problem. Must've been a Mobo DOA. Back to Maplins it goes.

 

[OhSnapWord]

Test it with a known working PSU. Some boards will not post if they detect a surge from the PSU.

I've seen this same exact issue before. The lights and fans would come to life but no post. Replaced the PSU and problem solved.