I've put together a new build and have been troubleshooting this problem for the past week. I'd be grateful for your comments as I'm losing the plot here:)
These are main components:
Asus P5KPL/1600 S775 G31 ATX
Intel Core 2 Duo (E7400) 2.8GHz
Trust PW-5250 420W Low Noise Big Fan
Kingston 1GB HyperX DDR2-800 x 2
After putting it all together, I hit the power button and it kept on beeping. All of the fans were turning. So I turned it off. Then there was a slight burning smell. Next time I tried, nothing would turn on.
Now, only the motherboard light remains on. When I hit the power switch, the chassis fan spins for literally 1 second and then turns off. Nothing else comes on or turns.
I troubleshooted using Multimeter:
Took the PSU unit out. I put a paper clip between the green wire on the ATX and the black wire. Powered it up and the fan was spinning.
Connected it back up to the board. Used the multimeter to measure the red, yellow and orange wire readings whilst I pressed the power button and the voltage readings go up to their expected numbers and then go right back down to zero (they would because the PSU doesn't stay on I guess).
Could this be the s---ty PSU I bought or could it be motherboard shorting?