Windows 10: My third monitor starts with only half a screen

On startup my vertical monitor has wallpaper on the top half, but just black on the bottom Screenshot. The black half also doesn't update back to black when something isn't there anymore, so a window will stay there visually even if it closed. The only way to fix it, is to open the display settings and move the monitor a little bit so it updates. Then the wallpaper stretches correctly and it stays functional until I shutdown again. What could be causing this?

:)

 

Monitor - half of it is black

Running w10 and up to date as of June 7/20. Running 3 monitors. Middle one (NEC 3090WQXi large screen) only has half a screen showing. Done settings, monitor, checks. All scaling and resolution is correct. Uninstalled drivers for that monitor and for video
card and rebooted. No change. Unplugged and reseated video cable. No change. Unplugged power cable to monitor. Let it sit half an hour, plugged it back in, and then got full screen. Left it alone, screen saver came on, woke it up, and back to half a screen
(left half black). Repeated unplug and leave it, but now still at half a screen. All diagnostics in device manager say monitor is working properly - sadly not. The setup has been working well for ten years. Not sure if this is a result of them latest W 10
update. The one thing I have not tried is to roll back the latest update - I hate doing that in case it causes more problems.

I have run out of ideas. Any suggestions? Apologies if it is in the wrong section. There was no option for display issues.

 

Screen Flickering At The Half Bottom Of The Screen.

Hi,

Thank you for writing to Microsoft Community Forums.

In order to get clarity on this issue and assist you with appropriate troubleshooting steps, please reply with the answers to the questions below.

1. What is the make and model number of your computer?
   
2. Have you connected any external monitors to the computer?
   

To narrow down the issue, I suggest you to try connecting another monitor as well as another monitor cable and check if the issue persists.

Meanwhile, try the below troubleshooting methods and check if this helps.

Method 1:
Troubleshoot Screen Flickering In Windows 10.

If the issue persists after checking with another monitor and the monitor cable, try the troubleshooting steps mentioned in
Troubleshoot screen flickering in Windows 10 and check if this
helps.

Method 2:
Changing The Screen Refresh Rate.

1. Right-click on an empty area on your desktop > Click on
   Display settings > On the right-pane, scroll down and click on
   Advanced display settings.
2. Click on the Display adapter properties for Display 1 > In the next window, go to
   Monitor tab > Under Screen refresh rate drop-down menu, try changing the desired Hertz rate.
3. Restart the computer after changing each rate and check if the issue persists.

Give it a shot and let us know of any changes.

 

Overclocking / Undervolting guide for Vega 56 or 64?

Here's a quick laundry list:

List of software to use for overclocking and testing
Examples:
Wattman (and how to find and use it, like an overview, including profiles)
Unigine Valley or Heaven (use this for quick testing while changing settings in Wattman and checking for stability / artifacts) ...just suggesting this
How to monitor cores / mem speeds and temps during testing (I've seen screen overlays, and others using GPUz)

Step-by step overclocking in Wattman
Fan speeds
Power limit
Temp limit
Voltages
Core speeds
Memory speeds