Question only 2 of 3 monitors work at a time

[Crome77]

using an older R9-270 GPU which has 2x DVI, 1x HDMI 1.4a, 1x DisplayPort 1.2.
Monitors: 1 - Acer KA272 and 2 - KB272 (all three use HDMI or VGA)
can only run two at a time. when the third is plugged in there is no signal to it. if I unplug one of the other two that are working properly then the third will come on.
I have read that the card will only run 2 digital connections at a time. so, I used DVI-VGA for one monitor, still not working. All monitors are properly set to the correct connection type in settings.

I have had 3 monitors on this card for years (1 - Acer KA2722 and 2 - HP V242h) and no problems. the two Hp were using DVI-D and the acer was HDMI.

I used DDU to remove the drivers and then reinstalled them. Tried different combinations of connections and restarted the PC / monitors, nothing worked.

Any help is greatly appreciated!

 

[Ralston18]

Update your post to include full system hardware specs and OS information.

If you right click an open area of the desktop are you able to access the GPU's Control Panel? Are all monitors listed even if one monitor is not coming on?

Are you able to manually uninstall the GPU drivers, and reinstall without using DDU or other third party tools?

Another way to look at things is to use Powershell. Objective being to get some sense of what Windows is seeing with respect to the monitors.

Open Powershell as Admin and at the PS> prompt enter:

Get-WmiObject win32_videocontroller | select caption, CurrentHorizontalResolution, CurrentVerticalResolution

You should be able to copy and paste the bold line into Powershell.

Source & credit:

https://devblogs.microsoft.com/scripting/use-powershell-to-discover-multi-monitor-information/

Run the "Get". Then copy and past the results here.

Try with three monitors and combinations of two monitors.

 

[Crome77]

Processor Intel(R) Core(TM) i7-4770K CPU @ 3.50GHz 3.50 GHz
Installed RAM 16.0 GB
System type 64-bit operating system, x64-based processor
Pen and touch No pen or touch input is available for this display
Edition Windows 10 Pro
Version 22H2
Installed on ‎11/‎9/‎2022
OS build 19045.3208
Experience Windows Feature Experience Pack 1000.19041.1000.0

there are three monitors in the GPU position settings, but one is smaller, and the number is grayed out. No information on it except when you look at advanced display settings. then is shows the monitor model and says "Display 1: Connected to AMD Radeon R9 200 series
Display 1 isn't active"


I uninstalled drivers from device manager then reinstalled again.

Powershell - AMD Radeon R9 200 Series 1920 1080
(all monitor configurations were the same result)

 

[Glenwing]

This is a limitation of the R9 270. Please see here: https://linustechtips.com/topic/729...v2/?section=active_adapters_for_multi_display

 

[Crome77]

This is a limitation of the R9 270. Please see here: https://linustechtips.com/topic/729...v2/?section=active_adapters_for_multi_display

Thanks for this information. It confirms what I was reading from other posts.

I am a little confused though, as stated in my post I have had 3 monitors connected to this GPU for several years already. None were using a Display port or active adaptor.
1 - DVI to DVI
2 - DVI to DVI
3 - HDMI to HDMI

My current setup.
1 - DVI to HDMI
2 - HDMI to HDMI
3 - DVI to VGA

why did it work before and not now?

 

[Glenwing]

Thanks for this information. It confirms what I was reading from other posts.

I am a little confused though, as stated in my post I have had 3 monitors connected to this GPU for several years already. None were using a Display port or active adaptor.
1 - DVI to DVI
2 - DVI to DVI
3 - HDMI to HDMI

My current setup.
1 - DVI to HDMI
2 - HDMI to HDMI
3 - DVI to VGA

why did it work before and not now?

Were all 3 independent? Not mirroring the same image on two displays?

 

[Crome77]

Were all 3 independent? Not mirroring the same image on two displays?

correct all 3 were independent.

 

[Glenwing]

correct all 3 were independent.

Interesting, shouldn't be possible. Maybe newer drivers are able to work around the issue under certain conditions the way they did on the R9 390 (which is if two monitors use identical timings, i.e. same model same connection, they can share one pixel clock generator and only use up one instead of both).

For the two monitors that are the same model, are you using HDMI for both and then VGA for the other one? If not, can you try that?

 

[Crome77]

I think that might have been what happened before. the 2 monitors that were the same had DVI - DVI connections but now I don't have DVI on any of the monitors, so it is DIV - HDMI and HDMI - HDMI then DVI - VGA to the odd one, didn't work.

Thanks for all your help looking into this! I ordered an active display port adaptor, will try it out tomorrow.
I think it is time to upgrade the rig!!

 

[Crome77]

received the active DP adaptor today.

Amazon.com

tried 3 different combinations of connections and still only two will come on at once.

any other suggestions?

 

[Glenwing]

received the active DP adaptor today.

Amazon.com

tried 3 different combinations of connections and still only two will come on at once.

any other suggestions?

Not really, sorry :/