1 beep on motherboard fix?

That chart isn't for your MOBO and BIOS, a single beep is: NORMAL.

1 Beep: VGA Detected, or Quick Boot is Disabled, or No Keyboard detected.

Q - What problem(s), if any, are you having now?

the screen is on, but its showing nothing on screen just backlit

Agreed with Jaquith, one beep is what is supposed to happen. It generally means that the processor got responses from all the hardware.

Are you sure that the video cable is plugged in right?

There is a built in graphics port on the motherboard, if you have the video card installed it will be disabled by the computer so if you have the video plugged into the motherboard port while the video card is installed you will get nothing. You would have to change the cable to plug into one of the ports on the video card.

If its already in one of the ports on the video card, then you can try taking out the video card and plugging the cable into the motherboard port and see what happens.

Also, your monitor may not auto-detect which input stream to use between digital and analog. if it is set to receive analog and you have digital plugged in then it will show nothing (and vice versa). You can play with these settings by using the buttons on the monitor which are usually located in the lower right.

I would agree to try both the onboard graphics (iGPU) and your HD 6790, and if both fail then sure try (1) stick of RAM failure the other (1) stick of RAM.

If needed then Clear CMOS - unplug the PSU for 5 minutes, move the Jumper for 5+ seconds and back gain, plug the PSU (power supply) and try to boot to the BIOS. Once in the BIOS press (F5) 'Load Optimized Defaults' and Save (F10) Yes and boot again.

Video - http://www.youtube.com/watch?v=rdHH9KrceR0

still only have the back lit screen

i have used 3 different ram sticks
changed the graphics card and tried on board graphics
re-seated the CPU
reset the CMOS
and still getting the same results

does this mean i have to replace my motherboard?

Is there any possibility you can use a different monitor or to at least test using a non-monitor (like a TV) temporarily as a monitor?

I would hate to see you replace the motherboard and the problem doesn't go away.

As far as I am concerned everything external to the case hasn't been ruled out. I would really like to do more to rule that out before I recommend replacing any components, if possible.

I agree again. Typically even a bad MOBO including BIOS and errors you'll see something on the screen, and if the MOBO were totally 'dead' then you wouldn't be hearing any beep(s).

I agree to check your monitor especially, as most do, have multiple inputs. There should be an input selection so I'd cycle through all of them.

I remember when I half ass connected a DVI and for a couple minutes I wondered what was wrong, but quickly realized I didn't have the cable properly connected -- guess what happened when it was connected properly -- duh me.

phew! you were right jaquith, i plugged my 3 monitors plus my tv like Raiddinn said, and the display was shown on the display port and hdmi monitors, im guessing the 2 DVI outputs wont give out a display. appreciate the help guys  

There (3) distinct DVI's Dual & Single link and DVI-A plus there's one with USB.

Typical DVI cabling: