ASUS Sabertooth P67 VGA Light on + No Video

Hi Everyone,

When I first built the pc, the video card wasn't detected.The vga and boot light came on and the video card fan was going flat out. So I updated the bios to 1802, the latest non beta release. It seemed to fix the issue and was working fine, then it went into standby and wouldn't start up. I managed to get it start eventually by leaving for awhile or reboot a few times. Now even that doesn't work. The vga light just lights up and have a blank screen. However I have another video card a EN8600GT, which when I swap it over works perfectly every time, except for the standby issue.

Here what I have tried:

Disabled pll over voltage
Checked the power supply - checked out ok
Reseated video card and ram
Checked all power connections (Motherboard 24 and 8pin and Pci Express)
Cleaned the pci express slot and the video card slot
Reset CMOS - Caused boot failure
Checked current video card in another pc - checked out ok
Installed MSE Standby Tool - Didn't show anything in the logfile

The only things I can think of to do is get a motherboard speaker, which is on it way and to breadboard the computer to check for shorts, which I really don't want to do. I have sent a inquiry to asus and am waiting for there reply.

Here are my computer details:

MOTHERBOARD: ASUS Sabertooth P67 B3
CPU: Intel i7 2600 3.4Ghz
CPU COOLER: Noctua NH-U12P SE2
RAM: Corsair Vengence 1600 Low Profile 16GB (CML16GX3M4A1600C9)
HARD DISK: 2 x WD Caviar Black SATA3 2TB RAID 1 (WD2002FAEX)
PSU: Corsair HX-850
VIDEO CARD: Sapphire HD 4850 Vapor-X
CASE: Corsair 600TM
------------------------------ Andrew