cpu - Computer starts for just a second and shuts down immediately

I have gathered all parts of my new PC and assembled them together. However, when I turn it on, the computer becomes alive for only a second or so, then shuts down. The lights flash, the fans start - but then stop almost immediately.

I'm not sure where to start from. The thing I'm thinking of right now is the lack of power, but the power block is 460W, should be more than enough...

I'm very confused, so any suggestions will be highly appreciated.

My configuration is:

1. CPU Intel s1155 Core i7-2600K BOX


2. MB s1155 Gigabyte GA-P67A-UD3-B3 P67 rev. B3


3. DDR3 8192Mb(2*4096Mb Kit) PC16000 (2000MHz) Crucial Ballistix (BL2KIT51264FN2001) (9-10-9-24)


4. HDD SATA 1000Gb Hitachi Deskstar 7K1000.C 32Mb (HDS721010CLA332)


5. PCI-E GF GTS450 1024Mb 128bit MSI (N450GTS CYCLONE 1GD5/OC)


6. Case CoolerMaster Elite 335 (RC-335-KKPK-GP) (120mm fan) Black 460W

Answer

Silly me, I haven't plugged ATX_12V_2X4 connector. I wasn't aware that it must be plugged as well as main 2X12 connector. This topic revealed the situation for me.