[P5Q Deluxe] Power On --> 5 seconds --> Power Off --> Sad Face

Hi Guys / Gals,

I'm hoping you can help, I've just bought some rather expensive PC components to build a new PC and it isn't booting! The behaviour is as follows:

(1) Press the motherboard power switch
(2) You hear everything start to power up (disk / GPU / DVD / CPU)
(3) 5 seconds passes
(4) Motherboard cuts out
(5) 5 seconds passes
(6) Everything powers up but nothing displayed on screen.

What's frustrating is the case doesn't have a PC speaker so I have no means to troubleshoot, but the specification is as follows:

Motherboard: P5Q Deluxe
PSU: PC Power & Cooling -- Turbo-Cool 1KW-SR
CPU: Intel Core 2 Duo e8600 (Wolfdale @3.13)
GPN: HIS ATI 4870 x2
RAM: Corsair 8Gb (4 x 2 Gb sticks)
Hard Disk: Western Digital SATA 500Gb

Troubleshooting steps taken:

(1) Removed all parts except CPU --> same behaviour
(2) Added a couple of sticks of RAM & GPU --> same behaviour.

I'm in the process of ordering a speaker, but in the meantime any ideas on what the problem is? PC Power & Cooling are meant to have a pretty rigorous testing regime for their PSU's so I suspect it's a motherboard fault....?

I have the same problem. My case has a speaker but it does not help, no beeps, nothing.

The motherboard is P5Q. The PSU is the one that comes with Antec Sonata III.

The motherboard has EATX12V 8-pin connector but unfortunately the PSU has only one 4pin 12V connector. I tried the following for the CPU power:
- 8pin power connector (dunno what it is)
- 4pin 12V connector

The result is the same. I suspect this has something to do with PSU and power connectors. If anyone knows why the motherboard would behave as described above, please tell! Thanks.