?CPU of MOBO failure - Advice please

[jon.brewerton]

Symptoms - Switch computer on - Fans spin and MOBO lights on for 1 second  - switches off for 2 seconds - Fans spin and MOBO lights on for 1 second - in a continuous loop. No beeps, nothing on screen.
Things I have tried
1. Clearing CMOS - No change
2. Removing all cards other than graphics aand all USB cables - No change
3. Removing all but one, then leaving just 2, then swapping around all sticks of RAM - No change
4. Replace Power supply - No change
5. Remove and replace CPU (with same one - not a new one) - No change
6. Take out 2x 4 12v connector from MOBO - Fans spin and MOBO lights stay on - but nothing on screen and no beeps.

2 days before this happened, I had a prolonged gaming session interrupted by one hang during the game.
1 day before this happened, Windows unexpectedly restarted leaving message on screen saying 'Windows has recovered from an unexpected restart' with the reference BSOD SomthethingOrOther.

Is there any way I can tell if this is a MOBO or CPU failure?

I'd really appreciate your advice

Jon

Gigabyte GA-EX58 MOBO, Core i7 920 Processor, Zalman CNPS Extreme cooling, Corsair 6Gb DDR3, Windows 7 nVidia 880 Graphics

[R_N_B]

Please try this if you have not yet.

Disconnect everything - all PSU connectors, all hardware including the ram, graphic card and anything else you might have connected to your mobo.

Remove the battery and then clear the CMOS using the jumpers. Leave the board for an hour or so. Use one stick of ram, your graphic card a HDD and boot into BIOS if you can. If you can then problem should be sorted. If not report back here and we will try the next step in the process to find the fault.

[jon.brewerton]

Yes - I did all that - I definitely had power supply disconnected from MOBO when I cleared the CMOS and I have tried with just one HD, graphics card and one stick of RAM. (I cleared CMOS as per the manual - shorting the battery terminals rather than a jumper) - No change. Could you help me with the enxt step. Thanks
Jon

[R_N_B]

Right next step is getting hold of a mate and getting him to let you pop your CPU in his system. If you have a spare board or system at home that you can use then do so. What we are trying to do is eliminate components as being problematic. 

Since you can not run memtest (need to get into the cycle for that) we will start with the CPU. However if you are going to a mates house - take all your kit with you. I would like you to actually test your graphic card please. You never know what can pop on PC tech.

[jon.brewerton]

Thanks. I've come to the same conclusion. I did try a different graphics card - No Change.
I'm afraid no mates with a CPU - but I've come to the same conclusion and have ordered a new CPU (£200+!). I hope I'm right!
If not, I suppose I could sell it on EBay for quite a lot.
I'll keep you informed. Delivery tomorrow
Jon

[R_N_B]

Bloody hell - if it is your old CPU that is toast then RMA the thing and sell the replacement I guess.  You could end up with two 920's mate if it is the board that is faulty. Good luck and keep us informed yeah.

[jon.brewerton]

An update.
I decided that the most likely cause was a failed processor.
I ordered a new one from DABS.
Package arrived today - NO PROCESSOR IN THE BOX!!! - Just the fan
Imagine my disappointment.
Currently trying to RMA to DABS.

[jon.brewerton]

I've just had a thought.
What SHOULD happen if you run the computer without a CPU in the socket?
When I try this, I get the same result. Should I get an error message if the motherboard is OK?
I'd appreciate anyone's advice.

[ETNiES]

It is really unlikely that you have broken your processor, unless you've been doing crazy benchmarks with your pc. I'd get a refund from dabs for time being and test all other parts on another machine, ram, graphics, everything!

[jon.brewerton]

Conclusion
It turned out to be the Motherboard.
I initially ordered a new processor from DABS. Box arrived containing only the fan and no processor! - Unbelievable but true. Ordered another from Overclockers but no change.
Replacement motherboard arrived today and all working OK. But had to reactivate Windows 7, even though it was exactly the same model of motherboard.
Put it all down to experience -ETNiES- you were correct!
Thanks to everyone

[ETNiES]

Glad you got it sorted anyway!