second display configuration issue

Hi All,

My configuration:

Windows 10 Pro x64
AMD Radeon HD 7800

Latest updates and video drivers installed, no hardware changes for 2+ months, latest significant Windows update 2 weeks ago, latest AMD video driver installed at least a week ago.


I have 2 identical displays connected via DVI to Windows PC over several years already with "Extend displays" configuration, and suddenly this configuration stopped working a couple of days ago when I was in the middle of doing something. Windows just replaced it with "Duplicate displays" configuration.


During PC startup I see BIOS diagnostics on both displays. Windows detects 2 displays. "Show only on 1" and "Show only on 2" options work as expected.


Problem: "Extend these displays" results in display 1 going blank and display 2 shows it's part of the image.


AMD Eyefinity (which creates virtual desktop over several monitors) works fine - which suggests that problem maybe only with Windows configuration.


What is done:

• checked cables
• removed and installed again latest AMD drivers
• removed second display from the System Devices, refreshed hardware list and added display again - now I have "Generic PnP monitor" and monitor with correct name in Monitors section
• searched for latest drivers for monitors and display adapters from Device Manager, nothing found

Next I replaced one monitor with monitor from different manufacturer, and everything works as expected - "Extend these displays" configuration shows extended image.


Any ideas what else can be done to fix the problem?


Thank you in advance.

Thank you for response @Caledon Ken.

If you "Windows Key + P" do you get an option to extend? - Yes

If you use Windows to identify displays does it know there is a 1 and a 2? - Yes

Do you have System Restore enabled and have you thought about using restore to go back in time. - I do have System Restore enabled, however I didn't think about rolling back as there were no software or hardware updates before the issue. OS loaded correctly, next after about an hour of working (editing text) second screen just became blank.

Yes I have verified that both screens operational - physically switched connections between displays and PC, but second display still played up.

Rolling back via System Restore was not an option as there were no system changes for a long time.

My theory is that in some configurations system struggling to distinguish displays from the same manufacturer and they detected identically.

When you switched displays did you switch their cables with them? - No

You said you removed and re-installed AMD drivers so hopefully that would have reset most configuration files? I wonder if repeating the process and running DDU to do the removal would be more complete. - Will give it a try

You might even try an older driver to see if this is an issue with the new driver. - There were no driver upgrades for a long time before the issue

Investigating the problem I swapped cables already and affected display is always the 2nd in the Windows configuration - looks like pure software problem. Sadly I don't have two identical monitors from different manufacturer to verify this theory.