Fault finding GPU or motherboard issue

michty_me · 2026-03-28T09:25:04+0000

I've had my Sapphire Nitro 9070XT for around a year now. It's been flawless until now.
Today I fired up the PC as usual but fans sounded louder, no display on the screen and a VGA light on the motherboard. Stripped it down, inspected the 12vhpwr cable on both ends, checked the PCIE slot and pins on the card, all good.

Plugged everything back in and away we went. All good again.

Three reboots later, The VGA lightcame back on and no GPU detected when I went in on the iGPU.

Setup is:

CPU: 9800X3D
Ram: 2x16gb 6000 CL28 Klevv Cras V
GPU: Sapphire Nitro+ 9070XT
PSU: Antec HCG 1200w
Motherboard: MSI B850 Tomahawk WiFi MAX

I've DDU'd and reseated again, reinstalled the drivers and it appears to be ok again. However, I don't have a lot of confidence. My next steps are try and fit it in the secondary PCIE slot to see what results I get there.

Any other test recommendations to decipher if it's a motherboard issue or GPU issue?

Edit to add: Currently running some OCCT stability tests.

ED209 · 2026-03-28T10:34:20+0000

Could you try the GPU in 1 of the other PCIE slots and see if you still have the issue?

Do you see the GPU at all when using the IGPU to boot?

michty_me · 2026-03-28T10:45:27+0000

That was my next step if it disappears again. Try the lower PCIE slot and test.

Last night when I reset the bios to get the iGPU activated, only the iGPU was showing. No sign of it showing in Windows. One thing I did notice was that the GPU RGB turns orange when the issue occurs, it's set to white and shows white when it is operating.

mickyflinn · 2026-03-28T10:49:37+0000

Do you have another pc you can try the GPU in ?

michty_me · 2026-03-28T11:10:17+0000

mickyflinn said:
Do you have another pc you can try the GPU in ?

I don't unfortunately. I'm trying to get hold of a different GPU from friends. I may buy a cheap GPU for keeping in times like this.

tamzzy · 2026-03-28T11:55:54+0000

tbf the most likely culprit here is the 9070xt
unlikely to be the mobo as the slots are just electrical circuits and yhe pcie controller is on the cpu io die, where the igpu is located too

michty_me · 2026-03-28T13:03:37+0000

tamzzy said:
tbf the most likely culprit here is the 9070xt
unlikely to be the mobo as the slots are just electrical circuits and yhe pcie controller is on the cpu io die, where the igpu is located too

I'm suspecting the GPU too to be fair.
I'm going to try buy a cheap GPU for testing purposes. Or possibly borrow one from a friend for a little bit. So far it's still running.

Tetras · 2026-03-28T13:51:37+0000

michty_me said:
Any other test recommendations to decipher if it's a motherboard issue or GPU issue?

I assume you're not using a riser?

Have you used the support bracket?

michty_me · 2026-03-28T14:08:52+0000

Tetras said:
I assume you're not using a riser?

Have you used the support bracket?

No risers, No cable extensions on the GPU, No PCIE to 12VHPWR, It's a direct 12VHPWR cable from the PSU. The support bracket has been fitted since day one.
The second time it diisappeared a tried giving the GPU a wiggle to see if that would cause it to detect but it didn't. Only a full removal and reseat worked but this time I cleaned the PCIE 'pins' with some isopropyl alcohol.