CPU or Mobo?

[Luxzar]

I'm hoping for a cheap answer but dread the worse already.

Foxconn P35A
Quad Core Q6600
Antec 650Watt PSU

Having newly built my first PC all was going well, loading on some software. Software stops loading so i escape and shutdown the system (Vista). No reboot happens just a quick start and stop of the fans, so i removed all components except for the PSU, Mobo and CPU. The PSU fan only comes on after i remove the CPU from the MOBO. I have not attempted to overclock any component and the CPU fan looked firm and was running. I don't have any spare CPU's to try or Mobos. Kind of hoping one of you clever people can tell me its something other than the CPU being fried. My other concern is if i get another CPU how do i make sure it doesn't happen again.

Any help much appreciated.

 

[kimsland]

BenchTest your system

Motherboard removal required

 

[Luxzar]

Ok i've taken the board out of the case and taken a good look for any kind of damage to the underside of the board, loose items that may course a short and see absolutely nothing. No improvement the power supply just turns itself on and off repeatedly. I'm at a loss as to where to go forward with this now?

 

[kimsland]

I'd start with Power Supply

 

[Luxzar]

Further experimentation and i find that if i disconnect the CPU power cord then the PSU runs fine and the CPU fan runs fine as well. I have taken a close look at the CPU power connector and see nothing untoward. Is it possible to pin point the problem knowing this information as well. I don't think the CPU could have overheated as i was able to shutdown the OS prior to the problem arising, i didn't touch anything in the case either between shutting down and starting it back up again, the only thing that changed was me relocating the Keyboard wireless stick from a case USB to the Mobo USB.

 

[kimsland]

Unplug all externals
Disconnect the front USB (on the motherboard)
Unplug any PCI card including video (even if no onboard video)
Disconect the 20 Pin Power Adaptor
Disperse the voltage again (ON button in for 30 secs)

Put the pci video card back in
Put the 20 pin plug (and 4 pin CPU plug) back in
Leave the front USB out

Plug in the power and video external cords only (forget mouse and keyboard)

Turn on

 

[Luxzar]

Thnaks for sticking with me through this Kimsland

I tried your suggestion and still the same as before, the only way to get the other fans going is by disconnecting the CPU Power cord.

Where now, RMA a component back if so which one?

 

[kimsland]

Power Supply
Possibly Motherboard