PC stopped booting. Help!

[zulk]

Hi,
Mobo: Asus P8P67
GPU: XFX 6870
PSU: Zalman 750w (ZM750-HP)
RAM: 3 x 2GB AVEXIR DDR3 1600C9
CPU: i5 2400 @ stock

Thursday morning tried booting up. Mobo gave me solid red DRAM light, tried to do MEMTEST on it, light flashed for a few minutes then went solid again. No POST. Unplugged everything and tried again, same result (only had PSU, CPU and HSF connected).

Was confident it was the mobo so went and got a new one (can claim it back on tax), Gigabyte Z77-D3H. Installed CPU with HSF on to that. Booted, CPU fan spins up for a couple of seconds, stops, PSU and system fans keep spinning for a little longer then whole thing shuts down. Repeats until power is turned off.

Went and grabbed a new Corsair CX600 PSU. Same results.

Don't have a system speaker on the case (Antec 300) so don't get any beeps.

I have tried breadboarding the mobo to rule out any shorts. Have been shorting the PWR SW in order to start it to rule out a short in the power button circuit too.

The only thing I haven't changed is the CPU and HSF. It's not likely that the CPU would have randomly died over night on the P8P67, is it? Could the HSF be causing dramas?

Summary: P8P67 board gives me solid DRAM LED and the MEMTEST doesn't do anything helpful.
Gigabyte board, CPU spins for a couple of seconds then stops, all other case fans continue spinning for a little longer then shut for a few seconds then it all happens again. Have tried new PSU, pulled out all RAM and GPU and anything else connected in.

Is there a way I can get the system to beep without a system speaker? (a way to hook desktop speakers up to it?)

Any ideas on the problem? Could the HSF cause something like this?

 

[smorizio]

on the asus mb did you try one stick of ram in the mb at a time and did you move the ram to another slot. the problem with newer mb is the memory controllers are built into the cpu and not the mb. sometime if a stick of ram goes bad it can hang up these new mb. with the new mb the ram may not be spec for the intel cpu..most of these new mb are looking for 1.5v ram. some of the older 1.6-1.65 ram wont post in the new mb but will run if another stick is added and the bios ram and voltage is changed first then the ram is added. i would on the new mb look at the ram guild and pick up some ram that on in. any good ram that would on the z77 should work for the other mb too. if it not the ram then your left with a cpu that the memory controller inside of it went bad. o on the new mb check that the pins are fine on the cpu and mb..some time you can have a bent pin.