Computer boot up to Windows, but no display (monitor "no signal")

[Maxime506]

Hi,

I was playing Rise of the Tomb Raider when all of a sudden the screen went completely dark ("no signal"), no warnings displayed, and rebooted. After this, the monitor continued to display"no signal", but I can hear Windows welcome/boot up sound.

The motherboard has no Integrated graphics, but when I book the monitor to the card, the system can boot, but there's no signal on monitor. Not even the bios screen, or blank screen of death.

If I plug in my old HD 7950 GPU in primary PCIe port, with the 7990 on second port, the second card cannot be detected, using GPU Z, device manager, or even atiflash (do's and Windows mode)

The GPU in question is HD 7990 (essentially two 7970 on one PCB). it's underclocked to 925 MHz core, and voltage is lowered to 1100mv for each GPU during gameplay, and the GPU temperature, both of them didn't go above 76c, according to rivatuner on screen display in the game. The game ran almost three hours and no signs of warnings (such as game crashed, DirectX errors or bsod)

What can be the cause and how do I fix it?

Rig specs:

AMD FX 8300 runner at 3.6 GHz

Gigabyte 970a-ds3p motherboard

16gb crucial memory

Corsair CX 750M PSU

Sapphire HD 7990 GPU

 

[rgd1101]

can you boot into safe mode with the HD 7990?

 

[Maxime506]

@rgd1101 unfortunately, there's no display output from HD 7990, so no I cannot boot to safe mode with that. I can boot to safe mode with HD 7950 as primary adapter, but even so, the 7990 never showed up at all.

And very strange, HD 7990 by itself can boot into Windows even there's no Integrated graphics on my board, and produce no display. I can let my rig run 30 minutes or something, press the power button and the rig can shut itself down normally (by observing the HDD led activity)

Flipping the bios switch makes no difference, although I never ever flashed the 7990.

 

[rgd1101]

safe mode should use the basic generic vga driver. if it can't even do that, it failed.

 

[Maxime506]

But I wonder how it can still boot into Windows 7 even though the system cannot see the card. I've seen lots of cases in forums and the other cards cannot Post. That's why I have hope that the card is still working somewhat. Otherwise the rig won't even boot.