Hi All, Hope somebody can help me out here
 
I've had a system running solid for about a year now.  But recently i started having some issues where the system would freeze.  So i reloaded Windows XP Pro and ran fine for a day before it froze again and i couldn't boot anymore.  I can't even get into BIOS.  All signs pointed to MOBO so i RMA'd it and just installed it again but i get the same thing.  I've tried bare bones system, different RAM, different graphics card.  So i guess the only thing that is left is the CPU or PSU???  I have read that if one of the PSU wires is bad (gray i think) the system will stay in reset mode.  And i believe that even if the CPU was bad I should still be able to get into the BIOS.  Any other ideas?  I can't see or hear what the POST codes are since i have the 680i LT...Specs below
 
When i start the system power to the MOBO is supplied, fans running and HD spinning but nothing happens
 
eVGA 680i LT
Intel e6600
eVGA 8800 GTX
2gb  Corsair DDR2
Corsair HX620 PSU
2 x WD Raptors (Raid 0)

Usually it seems that it's very very rare for a cpu to go bad.  Can you test the PSU in some way?  Or do you have a spare around anywhere?

don't take this as gospel,,but,,when my 350w enermax started to fail everything got slooower,until i installed a new psu,plus you say that it has run fine for a year,?, do check all your connections,make sure that your video card is properly seated etc,etc...

Clear cmos. Try each stick of ram in each of the slots. Try w/o the 4/8 pin cpu power cable. Try with only 20-pin mobo power cable, if the other 4 pin can be removed.
 
Bring it to a store before you waste any more money.

Make sure cmos is cleared. Make sure the cpu is well fitted. The Psu should be turning a light on the motherboard and see if power is being sent to the board. After that check to see that all the cords are plugged in properly.  
 
Another thing could be make sure you put each pin correctly for the reset and power button.