All PC specifications are in signature and I want to say that i tried all suggestions from other topics and they aren't working.

Hello, my setup was working almost 3 years without problems.
Two days ago i tried to power up my PC, and got 5 beeps. so I checked Dr. debug and it shows "d6" error.

Things that i do/checked:
-Power supply is in very good condition
-CPU is working
-RAM is working
-HDD is working
-clearing CMOS with: button, jumper, taking battery
-All cords are connected correctly

And now the tricky part:
-I borrowed VGA from my friend mounted it in my ASRock and its working OK.

-Went to friend and put my VGA into his motherboard and its Working!

So if motherboard and VGA working I put VGA into my motherboard and it isn't working.

and my question is: What the hell?? If everything is working why my PC isn't?