Black intermittent screen on wide screen monitor and windows 10

boongywoongy

I used to have a two screen setup but having donated one to somebody when I now start my desktop PC (with Windows 10) on just my LG ultrawide 29WK600 it shows an intermittent black screen with flickering horizontal lines.

The screen is also pixelated when the black screen isn't present. I thought that it could be a display/driver issue so I have reinstalled the LG graphics driver and tried to play with the display settings to no avail. Oddly, when I connect my laptop to the screen it seems ok. 

I've also tried swapping the hdmi cable (still the problem) and connecting the PC to a Philips TV which worked fine. 

Any ideas?

Can my graphics card suddenly not cope with the ultrawide monitor?

A video of the problem: 

https://youtu.be/dKATngC-ozE?si=ul6CpwO8T2Gqmf2D

booneruk

So the monitor worked fine through the same cable when there were multiple monitors in use, but not now there is only the one? That's very odd. Try setting the refresh rate to 60hz to rule out a cable being pushed beyond its tolerance 

https://support.microsoft.com/en-gb/windows/change-the-refresh-rate-on-your-monitor-in-windows-c8ea729e-0678-015c-c415-f806f04aae5a

Vitor

The "twinkling" or static-like effect, especially when it shifts or shimmers, is often linked to faulty video RAM (VRAM) or a dying GPU. Run a GPU stress test (e.g., FurMark or Heaven Benchmark) — see if the issue worsens.

boongywoongy

booneruk said:

So the monitor worked fine through the same cable when there were multiple monitors in use, but not now there is only the one? That's very odd. Try setting the refresh rate to 60hz to rule out a cable being pushed beyond its tolerance 

https://support.microsoft.com/en-gb/windows/change-the-refresh-rate-on-your-monitor-in-windows-c8ea729e-0678-015c-c415-f806f04aae5a

Tried this already. It was at 55.xx hz and then I changed it to 60hz but it didn't help unfortunately.

booneruk

boongywoongy said:

booneruk said:

So the monitor worked fine through the same cable when there were multiple monitors in use, but not now there is only the one? That's very odd. Try setting the refresh rate to 60hz to rule out a cable being pushed beyond its tolerance 

https://support.microsoft.com/en-gb/windows/change-the-refresh-rate-on-your-monitor-in-windows-c8ea729e-0678-015c-c415-f806f04aae5a

Tried this already. It was at 55.xx hz and then I changed it to 60hz but it didn't help unfortunately.

Ok. You also say when it's plugged into a TV with the same HDMI cable it's fine, and a laptop plugged into the monitor with the same HDMI cable is also fine?

This is all very odd indeed. If it were me I'd try a DDU uninstall of my graphics drivers ( https://www.guru3d.com/download/display-driver-uninstaller-download/ ) and then reinstalling the latest version for my graphics device (AMD/Intel/nvidia). Though that's more a stab in the dark.

Do you also have a Displayport out on your PC and a Displayport cable? I'd try that too.