New build problem - help"!

[Inquizitor]

This is the system I've just built:

Intel Core i7-2600K 3.40GHz (Sandybridge) Socket LGA1155 Processor with FREE Lost Planet 2 PC Game - Retail 1 £239.99

HIS ATI Radeon HD 6950 2048MB GDDR5 PCI-Express Graphics Card 1 £208.32

OCZ Vertex 2E 120GB 2.5" SATA-II Solid State Hard Drive (OCZSSD2-2VTXE120G) 1 £183.32

Asus P8P67 PRO Intel P67 (Socket 1155) DDR3 Motherboard - (Sandybridge) 1 £119.99

Corsair Vengeance 8GB (2x4GB) DDR3 PC3-15000C9 1866MHz Dual Channel Kit (CMZ8GX3M2A1866C9) 1 £116.66

Antec TruePower New Modular 750W Power Supply 1 £91.66
LiteOn iHBS112 12x BluRay-RW / 16 x DVDąRW Drive - Black (OEM) 1 £65.79

Coolermaster CM-690 II Advanced Dominator Case - Black 1 £64.16
Hitachi Deskstar 7K1000.C 1TB SATA-II 32MB Cache - OEM (0F10383) 1 £36.59

Akasa AK-CCX-4002HP Venom CPU Cooler (Socket LGA775/LGA1155/LGA1156/LGA1366/AM2/AM3) 1 £29.78



....on powering up, I get no output to the monitor. System fans, LEDs come on. After a few seconds, it powers down. Then a few seconds later it powers back up. It does not power back down again.

Does anyone know what the problem might be, something obvious with my setup (like being a dolt and buying incompatible RAM), before I do a detailed bit of detective work?



(fyi, PCI-e power cables are plugged in on the gfx card)

 

[Inquizitor]

4/8 cpu connection?

all standoffs in place?

you tried reseating ram?

did you apply TIM between cpu and cooler?

8pin CPU connection is in
RAM reseated
Thermal paste betwenn CPU and cooler

There's no keyboard response either.

Not sure why it's not an infinite cycle of power ups and downs, just the once....

 

[Inquizitor]

so it powers on then off and powers back on again as normal?

Yes.

Some progress - the memory was apparently slightly misplaced. Another reseat and I now get keyboard activity, indicating a BIOS at least.

I pressed a button to do a MemOK! test, which is now turning up alright.

Still no output to the monitor. It no longer reboots itself the once, either.