Custom build won't POST

[Guest]

Hi, i've just assembled my new PC and when turning it on, the PC itself has power but nothing shows up on the screen, I just get a 'no signal' message from my monitor.

Specs:
Galaxy 3 chasis
AMD FX6100 CPU
ASUS HD 7770 GPU
Gigabyte GA 990 FXA UD3 motherboard
Corsair Vengeance 2x4GB RAM
OCZ ZS 750W PSU
Hitachi 500GB HDD

Everything powers on OK, all fans work etc, and the screen itself (It's a TV with VGA/HDMI ports) which shows whether or not there's a connection to a certain thing actually shows a little symbol saying there's a HDMI connection so I know it's not the cable itself.

I've also tried using a VGA cable but get the same issue. I've got a system speaker coming in the post so I can do a beep test, but i'm wanting ideas before then.

I've tried rebuilding it outside of the case but nothing changes.

I took a 12 sec video of the GPU, as every so often the fan will increase in speed as if it's trying to boot up or something.:

http://youtu.be/Tscl6WC6yDs

Any suggestions appreciated.

 

[scorpinock2]

Your computer could be stuck in a boot loop due to a flaw in the motherboard. The only other issue I could see is it being an issue with the graphics card. Have you tried very type of connection available on the card? Are all the power connectors snuggly in the card?