Stu.H

Ok PC isnt powering on at all, have checked the pinouts from the ATX power supply with it plugged in and a do get the 5v+ (VSB) where it looks for the switch on

PS_On is 3v, however NOT when plugged into motherboard, drops to 0v, and removing the case switch doesnt affect anything..

As the light does flicker for a split second, my guess is with CPU...

Only I dont want the chap spending £60+ on a new CPU as its an AMD 3400+

JjCoDeX75

Could be motherboard also - Have you tried a diff PSU to absolutely rule it out?

JJ

Rab

It's something to do with the dilithium crystals....

Jamz

try removing all the cards (pci/agp/pcie), hard disks, cd/dvd drives and memory modules one by one, could be one of those. My money is on blown motherboard, try another PSU first though. Unlikely it's the CPU unless it was really badly handled when it was installed.

nilrem

use a spare PSU to check it isnt on the blink, the motherboard could be switching it on, but then the main 12v supply is fucked so aint working properly!... if not, it could be the mother board... but to me it sounds liek hte PSU...

m4cK

Try resetting the bios by crossing the jumper pins.

JohnnyB

First port of call PSU

roybacer

deff try another psu and kettle lead before trying anything else