The hard drive should not matter it should at least post bios regardless of hard drive configuration. The first thing I would do is make sure that both the power connector the processor (4 or 8 pin) is connected, and also the power to the motherboard (24 pin). Due to the fact that you tried using both onboard and dedicated graphics with no separate results, it seems to be an issue with the motherboard and something not properly connected with it, or there's the rare chance that you have defective hardware. One suggestion that I would give is try to locate the Bios chip on your motherboard, if it is one that is socketed to the motherboard (and not wired onto) I would suggest GENTLY pushing it down, in the past I have encountered motherboards where the bios chip was not making full contact and it would not post
EDIT: ignore the suggestion I made about gently pushing on your bios chip, i looked up your MOBO and it has a chip wired to it. Apparently other people have had the same issue you have, Asus answered one of their customers with the following advice:1. Clear CMOS. Turn off the computer. Turn the switch on the back of the power supply to OFF. On the lower right corner of the motherboard is a jumper marked "CLRTC", move the jumper from positions 1 and 2 to 2 and 3. Wait about 10 seconds, and move the jumper back to positions 1 and 2. Power on the computer.
2. Try to plugging a system speaker to the 4-pin speaker connector (lower right corner) and monitor if any beeps that occur when you turn on the computer.
1 short beep = keyboard issue
1 long beep and 2 short beeps = memory issue
1 long beep and 3 short beeps = VGA issue
1 long beep and 4 short beeps = hardware component issue
3. Try reseating the CPU, memory, and video card.
4. Please make sure to check the power connections, specifically the 24-pin and 8-pin/4-pin. Have you tried using another power supply?
Edited by SevenCipher, 29 July 2012 - 04:28 PM.