Windows 7: Graphic card doesn't display and some problems.

Hi. I have a little, weird problem.
Firstly my hardware:
CPU: Phenom x3 720
GPU: MSI Radeon 6850 OC (bought about week ago)
RAM: 2x Kingston HyperX DDR2 1066Mhz
MOBO: Ta790gx 128M
POWER: Seasonic Ss500et 500W
MONITOR: Old Daytek 17" (D-Sub slot)
Today everything worked fine, but after reboot my monitor didn't display anything. Diode was shining as in sleep mode. I tried to use second DVI port (with DVI->D-Sub adapter) but no difference and PC wasn't running well(no BIOS beep and PC was stopped i think). I unplugged my Radeon card and connected monitor to integrated card and then it was working perfectly. But... I have DVI and D-Sub integrated, first one doesn't work with adapter, D-Sub works... Weird... I decided to plug again my Radeon and check again, but the same as before. I am confused, don't know now that card is broken or maybe this adapter? Ah, Radeon's fan is running when i turn on PC and i feel warm temp so it seems that it is working. Please help you gentlemen.

Considering your monitor size, it probably cannot handle the resolution and frequency range sent by your video card. If it is the case then try checking it by booting from safe mode (hit F8 after POST). And see if the card works.

Kevin.

So when i plug Radeon PC won't start, when i start all fans are enabling but PC stops and there is no characteristic beep. After unplug and connect monitor to integrated device, everything works well again...

I feel a bit hard to conclude.
You were saying it was working before reboot, did you mean the vid card had already installed? Did you connect through DVI adapter or to D-Sub port?

Radeon was bought 6 days ago and worked perfectly and wasn't stressed so much(max temp as i had was 60 degrees C), this card was connected by adapter, because there are two DVI ports and my monitor has D-Sub connector only.

Ah and one more fact. If Radeon is unplugged from PCIE but with power supply 6 pin connected then PC is starting normally, but if card is inside of PCIE port then pc stops on booting now(but several times runned but still with no display). I have 2 these ports and the same thing on both.

Based on the latter explanation I might suspect the card might be the cause of the problem as also you mentioned that it all work when the PC runs without it.
If it still possible, you may have to return the Vid card for replacement. I do not reconmmend you exercising more attempt to insert it again to PCIe slot as probably it will cause more serious problem to the Mobo.

OK i will go to shop tomorow and we'll see... Thanx for help, beer for you.
But if someone have any other ideas please sugest.

Sorry for not having more accurate assistant in solving the problem, but avoiding further problem still a good choice to make.
Wish you luck for the replacement.