I recently built a new PC with a 9800X3D, Asrock B850 Livemixer motherboard, and an Asrock 7900XTX Taichi GPU. It posted successfully the night I assembled it, but now it won't post at all. I've tried various troubleshooting steps and even took it to a professional. They tested my setup with two different XFX RX 580 cards and a GT710. The XFX cards didn't work, but the unpowered GT710 did, which leads them to believe that the motherboard might have issues with powered GPUs. I'm looking for any advice or thoughts on what might be causing this problem.
2 Answers
I'd suggest trying a different power supply. Since your setup posted with the low-power GT710, it might be that your PSU isn't providing enough power for the bigger GPUs. It's possible there's a fault with the PSU that prevents it from delivering what the more demanding cards need.
It might be a BIOS issue. Some motherboards can act up with newer GPUs unless you flash them to the latest version, so it's definitely worth checking if you're running the most recent BIOS.
I'm using an MSI 1000W PSU, and it worked fine just one night before. It's so frustrating that it just stopped posting overnight!