I have a 6900xt powercolor and the hdmi output has been dead for a couple months. I can use a DP to HDMI adapter and it works but the HDMI will only display the bios menus and the windows loading screen then drops the signal. I have tried new cables, fresh drivers, fresh bios (mobo+GPU), clear PPT, re-flash card bios. To see if it was a windows issue I checked to see what happens on Linux and got the same result.
If anyone has any tests they want to suggest I am outta ideas. When the system is displaying the windows startup screen is the display is still using the bios? I have good connection, no riser cables and it's detected 4G@16X. With the display port-to-HDMI adapter I can run 4k@60hz but HDR is unavailable. Oddly enough I was messing around with it and was able to turn on HDR with the display set to 1920x1080, but after I set it to 4k it shut off. Now though, I can't get it to turn on at any resolution. I am going to test it out on another display tomorrow for the hell of it. But I don't think it has to do with the display.
It is a custom loop, but I put valves between each component and the distro plate so at least I don't have to drain the whole system. I also have another system I built for my living room that's very similar to my office system, but it has an AIO for the cpu and an air cooled founders 6800xt. So I can test the system with that card but I can't test the 6900xt on the other system.
So with all that in mind if anyone wants to suggest some diagnostic steps I would like to hear em. I'll pull the card in a few days and hopefully knock out all thee diagnostics, maybe remove the waterblock and take a look at the board and I don't wanna miss anything.
Adaptors are usually rubbish and don't work very well!
You would need to connect Display Port to Display port..