Just a shot in the dark. But have you tried another monitor? Since you seem to have swapped out every other part.
/Dan M
Now I have a problem that is baffling me! I replaced the mb in my brothers computer with a brand spanking new MB. It had seemed that the problem was the motherboard. The Power Supply seemed fine. It worked when hooked up to another Motherboard. Anyway, the problem is there's NO video! :-( Which it didn't work on the older MB, however, the video card worked in another computer. I even used another power supply with this one, just in case the installed power supply wasn't putting out enough power. Same thing.
Switch memory sticks, no go. Even replaced the CPU in case the old cpu was shot. Even that didn't work. Have totally run out of ideas. If anyone is burning the midnight oil and just so happen to be sitting in front of their computer, I'm open to any and all suggestions. :-O
I just knew installing the new MB went TOO smoothly!
TIA