No Video Output on Boot

[bytecut]

Hello,
I am unable to get my computer to display video. When I turn it on, all the fans spin up, and I can feel the hard drive spinning, but my keyboard's lights don't light up and the HDD activity LED doesn't appear to show activity.

The computer was working perfectly fine until yesterday I went to replace the stock cooler with an aftermarket one (which required me to remove the motherboard to mount bottom bracket) and add an additional stick of RAM.

I have tried re-seating everything, booting with 1 stick of RAM, removing MB battery for 30+ minutes to reset the BIOS, and I am just at a loss. All parts are still in warranty since I just built this system in January, but I would hate to have to RMA a lot of parts and not be able to use my normal system for a while.

Any suggestions are much appreciated!

Specs of the Computer:
AMD Phenom II x4 955
G.SKILL Ripjaws Series 2x4GB @1333MHz
HIS Radeon 6870
Gigabyte GA-770T-USB3 Motherboard
640GB Western Digital HDD

 

[festerovic]

couple things...I know you may have tried some, but maybe you haven't:

1)double check the CPU coolers fan lead and make sure it is plugged in. PCs wont boot without the lead plugged in.
2) what PSU do you have? For the listed system you need a quality 400watt or greater.
3) you mentioned you added a stick. Was it from a matched package with 2 chips and you just now added the second chip, or you bought another just like the first and added it? Your new RAM may be bad.
4) Things that directly access the power supply from the motherboard, like USB, 1394 and maybe others, if the port gets bent or there is a bent or shorted plug plugged in, the mobo may trip some protection circuit.
5) even though you reseated everything, try one more thing - reseat the CPU again, but also assemble the minimum amount of parts - mobo, video card, PSU, and etc outside of the case, and try again.

 

[bytecut]

Sorry, I didn't completely list everything. I have a 750w PSU, I have ensured everything is plugged in correctly, the RAM is the exact same RAM as the first stick I have, I've tried bare minimum setups. I think the only thing left for me to do is RMAthe motherboard and hope I get a working one back.

 

[kilo_17]

Have you tried breadboarding? Link's in one of the stickies

 

[bytecut]

I think I will this evening. Thanks for the suggestion.

 

[bytecut]

Reseat the cpu. Make sure its in the socket correctly. No display at boot with no post beeps is a sign of the cpu either damaged or not in the socket correctly.

I have reseated the CPU to no avail. I actually noticed the reply you gave me as I was preparing to fill out an RMA form for my motherboard!

Would I be better off attempting to RMA the CPU or both CPU and motherboard at the same time? I'm at a loss for what to do, I just wish I had my computer.

 

[bytecut]

Best answer selected by desolatemuffin.