PC Graphics

[matteo_angelo]

I've been at it for days, but my 6900XT Master will not post. 

Specs: 

• Ryzen 7 5700G CPU;
• TUF GAMING B550 PLUS Mobo;
• Radeon 6900XT Master 16GB;
• Samsung 970 SSD 1TB; 
• Corsair Vengeance 16GB RAM; 
• Corsair 1000W PSU. 

The GPU powers up fine, but I can only post using integrated graphics on the CPU. I can't see the GPU in the BIOS (even after updating to latest BIOS), but interestingly, I can see both the CPU integrated graphics and 6900XT GPU in Windows 10 device manager. When I install the drivers recommended by windows, there is no problem (but still no post), but latest AMD GPU drivers have caused windows to crash, and more recently, stay running but flag an issue with the GPU (Code 43). Note that this is all whilst I have my HDMI in my mobo.

I've tried removing and replacing the GPU, changing between HDMI and Displayport, deleting and reinstalling drivers, the works. 

How is it possible that the BIOS doesn't recognise the GPU, but windows does? Any help would be appreciated. 

Thanks

[vialli100]

Are you only plugging the HDMI/DP cable into your motherboard?

Plug it into the GPU, remove the cable from your motherboard..

Go into your bios and check if it has a setting to use your RX 6900 XT..

Also set your pcie-x to Gen 4.. it's probably on auto..

[Vynski]

First do what vialli100 suggested.  You will also need to go into the BIOS and DISABLE the onboard graphics.

The 6900XT is a PCIE 4.0 device.  Your motherboard only has 1 PCIE 4.0 slot (that is one of the handicaps of the Bxxx series motherboards regardless of brand), the others are PCIE 3.0.  Look in your motherboard manual and make sure you have the card in the PCIE 4.0 slot and as vialli100 said it would be advisable to set that slot to the 4.0 setting. 

[matteo_angelo]

Thanks for the reply. 

When the HMDI/Displayport was plugged into the GPU, my PC got stuck in a boot loop. I've double checked I'm in the correct PCIe slot and investigated the BIOS to see what setting that slot had attributed to it. Interestingly, it was set to Auto, but GEN 2/3 were the only other options. 

[hrpuffnstuff]

If the card output doesn't function its probably defective so send it back.  You should get a video output from any port on it at any time.  Also are the pcie connectors to it plugged into their own power rails on the PS?

[vialli100]

You will only see pcie 3 as your CPU doesn't support pcie 4..

[matteo_angelo]

Thanks both. I have taken the GPU to a repair shop and they have confirmed that it will not post so are in the process of investigating the issue. I will update the thread with a solution if/when they find one

[matteo_angelo]

Just an update, the PC repair shop had the same issues as me and couldn't see anything wrong with the GPU to warrant changing any components on the pcb. End of the road on this one. Thanks for all the advice.