LG ultrawide monitor flickering with vertical lines

[ourcore]

Hi everyone. I just got a Mac Studio with an LG 38" ultrawide monitor (38WN95C-W) and after about 5 hours of use, the monitor started flickering with thin vertical lines across the screen. I was initially using this cable since I read that I needed to connect via DP to get 144Hz, but the included TB/USB-C cable has the same issues. Before this started, my monitor was set to 144 Hertz in macOS, but then, it changed to Variable (48-144 Hertz). What's curious is that the image seems to get faintly burned into the monitor, so I left it powered off overnight and it went back to normal. Then, I tried it on my M1 MBP and it didn't have these issues (also at 1600p/144Hz), but when I plugged it back into the Studio, the issues started again almost immediately.

I tried resetting the monitor settings and different DP versions, but it didn't help. I've seen in some threads that there's no solution yet, but I wasn't sure if this is the same issue since I haven't seen any mention of the image burn-in and since it works fine on my MBP. Could be monitor or Mac likely be faulty? Thanks in advance.

 

[will16]

I have the exact same monitor connected to my Mac studio with no issue. I am using the TB/usb-c cable. Getting full resolution and 144 hz. Sounds like you‘ve ruled out cable and ports, having the same issue on all? But your MBP has no issue? Weird. Does the OS show the correct display model connected?

 

[ourcore]

I have the exact same monitor connected to my Mac studio with no issue. I am using the TB/usb-c cable. Getting full resolution and 144 hz. Sounds like you‘ve ruled out cable and ports, having the same issue on all? But your MBP has no issue? Weird. Does the OS show the correct display model connected?

That's actually good to know, thank you. I've only tried one TB port so far, but I can try another. Yep, no issue on the MBP. At first, I thought it was getting the lines too, but they were actually still burnt-in from the Studio. When I plugged it in fresh the next day, it had no issues. Yeah, macOS picks up the colour profile and max resolution/hertz.

 

[Pressure]

Try going to /Library/Preferences and delete the com.apple.windowserver.displays.plist file and then reboot.

 

[ourcore]

I'm still experiencing issues with my Mac Studio and this monitor and it's really frustrating. I ended up getting a replacement for the monitor (same model) and it seemed to be working better, but then the lines came back. They went away after a bit, but yesterday, the monitor started flickering again with the lines and turning it off didn't help. Restarting my Mac cleared the issues, but only temporarily. What's odd is that part of the windows also get burned in, meaning that I can still see portions when I switch windows, but it all goes away eventually (usually hours). I also tried deleting the PLIST file mentioned above and restarting the Mac yesterday, but it's hard to tell immediately if it had any effect since the issue happens sporadically. I've seen the lines since, but very briefly. When they do appear, I'm not doing anything in particular or resource-intensive.

I'm using the Thunderbolt cable that came with the monitor and macOS reads 3840 x 1600 @ 144 Hertz. I'm also using the stock power cable/adapter through a Belkin power strip. Could any of these be the issue or is it most likely an M1 issue that Apple needs to fix in software? I imagine it's unlikely that the Mac has a hardware fault. Does anyone have any suggestions? I'd really appreciate any help.

 

[Pressure]

I'm still experiencing issues with my Mac Studio and this monitor and it's really frustrating. I ended up getting a replacement for the monitor (same model) and it seemed to be working better, but then the lines came back. They went away after a bit, but yesterday, the monitor started flickering again with the lines and turning it off didn't help. Restarting my Mac cleared the issues, but only temporarily. What's odd is that part of the windows also get burned in, meaning that I can still see portions when I switch windows, but it all goes away eventually (usually hours). I also tried deleting the PLIST file mentioned above and restarting the Mac yesterday, but it's hard to tell immediately if it had any effect since the issue happens sporadically. I've seen the lines since, but very briefly. When they do appear, I'm not doing anything in particular or resource-intensive.

I'm using the Thunderbolt cable that came with the monitor and macOS reads 3840 x 1600 @ 144 Hertz. I'm also using the stock power cable/adapter through a Belkin power strip. Could any of these be the issue or is it most likely an M1 issue that Apple needs to fix in software? I imagine it's unlikely that the Mac has a hardware fault. Does anyone have any suggestions? I'd really appreciate any help.

View attachment 1994086 View attachment 1994085

And they are not showing up at 120 Hz?

 

[ourcore]

And they are not showing up at 120 Hz?

120 is an option, I've just kept it at 144

 

[ForbiddenX]

Did you ever find a solution to this? I'm having the same issue it seems with my AW3821DW but haven't found any solutions.