Red Boot Device LED when tryin to start up my computer!?!

[Dislocation]

I have recently taken my Graphics Card (EVGA Nvidia GTX 680 4GB) out to in order to remove some dust from it I made sure I had safely removed it as and have not damaged it in any way it was simply a quick clean like I usually do however now that I have put the GPU back in I just either get a Red Solid LED behind the GPU or a RED Solid LED below it which Reads Boot Device LED I have tried taking the BIOS Battery out for 5mins and putting it back in a couple of times I would get press del to enter the UEFI Bios Setting and others I would just either get my screen turning on but nothing appearing or Searching for Drives Please Wait I left this for around 2 hours then decided it wasn't going to find any drives please can someone help me here are my PC Specs:

Asus M5A99X EVO
AMD Phenom II X4 980
EVGA Nvidia GTX 680 4GB
4x 4GB Corsair Vengeance
1X 500GB Western Digital Scorpio Black
1x 120gb OCZ Agility 3 SSD
Corsair AX 850 PSU

If anyone could help me fix this I would be greatly appreciative and would also include a £10 Gift Voucher for Steam thanks!

 

[Dislocation]

A quick Update I have just tried to boot up and now on some occasions I don't get any red lights appearing.

 

[alexoiu]

Try reconnecting all SATA cables.

 

[Dislocation]

Try reconnecting all SATA cables.

Tried this but still no change its weird how the red lights vary however because sometimes I will get the one above my GPU and sometimes I will get the DEVICE LED Its so confusing

 

[alexoiu]

I would uninstall all components, but CPU and CPU cooler, make sure there's no screw or wire shorting the board, then reconnect them.

 

[Dislocation]

ok I shall try this tomorrow when I have a little bit more time thanks once again and I'll let you know if it fixes it!