Second graphics card suddenly making computer not work

[HartleyC]

I have two graphics cards in my computer, a radeon r9 200, and a radeon 7900, and whenever I have the 7900 plugged in, the computer won't boot, or display on either graphics card, but then, when I unplug the 7900 from the power supply, the R9 works fine, and I don't have any shops or friends around me that have a graphics card that I can test with. Could this be a problem with the power supply, or drivers, or would it be a dead graphics card? If I unplug the R9, and leave the 7900 connected, the computer will boot, but wont display anything.

[Zuexs]

I have a few theories based on my expeirence with cross-generational multi-GPU configs, but I'd have to know your PC specs before making any assessments. 

Could you supply your CPU, Motherboard vendor (and chipset/model number if possible), and any other PCI/PCIe cards you have connected?

If you can post that info I'll see what I can do for ya

[HartleyC]

On 5/8/2020 at 8:20 PM, Zuexs said:

I have a few theories based on my expeirence with cross-generational multi-GPU configs, but I'd have to know your PC specs before making any assessments. 

Could you supply your CPU, Motherboard vendor (and chipset/model number if possible), and any other PCI/PCIe cards you have connected?

If you can post that info I'll see what I can do for ya

I just noticed you responded, its a Sabertooth 990fx motherboard, amd fx-8350 processor, 16 gigs of ddr3 vengeance ram, the radeon r9 200 and radeon 7900. And its all watercooled. I'd have to check the powe rsupply sometime, but i think its a corsair 500 watt.

[Haro]

On 5/9/2020 at 5:15 AM, HartleyC said:

I have two graphics cards in my computer, a radeon r9 200, and a radeon 7900, and whenever I have the 7900 plugged in, the computer won't boot, or display on either graphics card, but then, when I unplug the 7900 from the power supply, the R9 works fine, and I don't have any shops or friends around me that have a graphics card that I can test with. Could this be a problem with the power supply, or drivers, or would it be a dead graphics card? If I unplug the R9, and leave the 7900 connected, the computer will boot, but wont display anything.

I think it's the gpu that is dead 

Power delivery gets worse over time and this is a pretty old GPU So I havey doubts that I'd will be able to display an image 

[HartleyC]

3 hours ago, TofuHaroto said:

I think it's the gpu that is dead 

Power delivery gets worse over time and this is a pretty old GPU So I havey doubts that I'd will be able to display an image 

Alright. I'm gonna bring it to someone to test, and if it is bad, I'll probably just replace till I can build a new system. 

[Haro]

Just now, HartleyC said:

Alright. I'm gonna bring it to someone to test, and if it is bad, I'll probably just replace till I can build a new system. 

Good luck