I'm just about ready to rip all of my hair out, so hopefully you guys can help me.
I have two Radeon RX 480 graphics cards in my computer (no crossfire), and I've always used two monitors: both HDMI, one plugged into each graphics card. I've never had any issues getting the secondary monitor to connect... until now. I'd fallen behind on updating my drivers (sat at 21.2--something for a while), and to troubleshoot some unrelated issues I was having with a game I was trying to run, I decided to update my drivers to 21.4.1.
Ever since, my secondary monitor will NOT detect.
There's nothing wrong with the monitor or cable itself, as if I plug it into the primary graphics card to test it, it works fine.
I even did a startover on my windows 10 because I was running into issues with windows update not working. Thought that was related, so I reinstalled windows and the driver issue has persisted.
other things of note:
Had the same issue. Go to Radeon Software > Settings > Graphics > Advanced (at the bottom) > AMD Crossfire (disable this). For some reason having AMD Crossfire enabled does not allow you to use two monitors.
Hope this helps, I was going crazy!!!
I don't know if you found an answer to your question or not but I'm still looking for one myself but the only resolve that I could find is a long involved one and it starts with DDU that you can get a GitHub or just Google it and you'll find it and after using that that clears out all of the drivers associated with your GPU and then you can go to the group policy depending on your version of Windows and disable the driver install in there and then you can't just use your old graphics for your motherboard and then it uses windows general purpose display drivers for your second port so you get a VGA of your graphics for your motherboard and then a Microsoft but then you have to keep your drivers from updating which mine are currently wanting to do all the time and so it's kind of not a good atmosphere I don't think and it's not a good fix but it's a way to get around it then I did that and that works and so I just thought I would share if you have any questions feel free to message me directly
I have found if you go to the display options in the AMD software (keyboard shortcut is Alt+R), in the top left corner press enable clone, and then once it loads on your keyboard press the Windows + p, and then press extend that worked for me. If you have any questions please ask.
I had the same issues after updating the the latest drivers.
What you have suggested does work, until the screen goes to sleep, I restart the computer, or a program crashes. Then my computer reverts back to one screen and I have to go through the process again of opening up the AMD UI, settings>Display>Clone screen>windows key+P>Extend monitors. A little frustrating.
Just wondering if anyone else has found a permanent solution to this issue? Perhaps AMD???
my gpu wont even detect my second monitor. I had a gtx 1660 ti and it worked perfectly. i just got a radeon 6750 xt and its been nothing but problems. it won't even detect my second monitor. I've tried everything everyone has mentioned above and nothing has helped. the screen just always says no input and my computer doesn't even detect it anymore.
I have 3x 4k monitors and suddenly, this happened to me. Apparently, there is an easy fix, if you have the latest driver:
Open adrenaline, select graphics > advanced > reset shader cache (restart? i can't remember if i had to do it)
But things went back to normal... it is a corruption of shaders data into the VRAM that can cause the issue.
I hope it'll help, Good luck!