New GA-P55-UD5 motherboard won't boot

[Nicholas Lee]

I am installing a new GA-P55-UD5 motherboard and it will not boot up properly.
I have a Zalman ZM750-HP power supply connected to this motherboard.

When power is applied, the blue power switch LED lights up, as does the red led for the s4/s5 power state.

On pressing the power button, the cpu fan starts, the s4/s5 led goes out, the leds for all the 6 power phases light, as does the blue led for the cpu and the group of 4 leds near the memory. Then the power cycles on and off every few seconds as the system tries and fails to boot properly.
NB: I can even remove the two CORSAIR TW3X4G1333C9A (4Gx2) DDR3 simms from memory sockets 1 & 3 and I still get the same pattern of LEDs.

Can anyone help me diagnose the problem?

[Mark]

I was not able to boot my system (P55-UD6) until I installed a graphics card.

Mark

[Beekeeper]

Nicholas, what is your CPU and VGA ?
do you hear any beeps from PC speaker connected to the MB?
tried with one stick of RAM ? or different vendor RAM ?
is power connected to ATX_12V_2X ?
open cpu socket and re-seat the cpu once again

[Freakapotamus]

without extra 8 pin power plug (EPS) and a the power to your graphics card ( if it has one)  the pc wont boot.

[davewh]

I  am having the same problem, the power button lights as does the red ACPI light, when I attempt to power up the red light goes out and appears to change to green, the fan starts for a few revolutions and then stops.
This happens with or without any components fitted to the motherboard.
The board is a P55 -UD5
Corsair Dominator GT memory
XFX GT 260 Video Card
i7 LGA 1156 2.8 Quad Core
From What it appears I have the same problem, being the PSU which is a 700w EZ-Cool.
Has any body got any sugestions I would be most grateful.
And also could someone suggest a PSU with an enough power and the correct 8 pin connector
Many thanks in advance

[Pottypete]

Hi,
A very good psu for your needs, And will give you lots of headroom,
Corsair 650W HX http://www.ebuyer.com/product/173104 - £90
regards

[davewh]

Hi, many thanks for the quick response, can I confirm that this PSU has that damn 8-pin and 24 pin sockets ?

[Pottypete]

Hi,
It's modular,
And should have Just about any connectors you may require,
Additional cables and conectors can be ordered if you require more than supplied,more than you can shake a stick at,
Regards