Monitor Flickering

[Estaric]

So my ultrawide monitor started flickering in the middle of use today and i cant explain what happened or how it got fixed. The area that started flickering covered about if the monitor was running in 16:9 in stead of 21:9 if that makes sense? I thought it was a cable issue so i unplugged it from my computer and the gray screen it displays when nothing is plugged in looked even worse than when it was plugged in it started flickering more and more so i turned it off and kept checking on it every hour or so and it wasnt getting better. Eventually I decided to plug it in and have videos play on it and the issue slowly started resolving itself to the point where now it is completely functional. I dont really understand how something like this is possible? Is there any explanation?
The monitor is an LG 29UM68.

 

[Bill_Bright]

Impossible to tell right now. Note intermittent problems that cannot be duplicated at will are the hardest to troubleshoot.

For sure, I would make sure the OS, your security, and particularly the graphics drivers are current. Make sure all data and power cables are securely fastened. Ensure the case interior is clean of heat-trapping dust, all fans spin freely, you have a good flow of cool air through the case, and all temps are good.

If the problem recurs, consider swapping in a spare power supply. Also, swap in a spare monitor. If the problem continues with the 2nd monitor, you will know the fault is on the computer side. If the problem goes away and stays away, the problem is likely in the monitor. It could be revealing if you could try that monitor on a second computer.

 

[Vya Domus]

Grounding issues can cause flickering.

 

[Bill_Bright]

It would not hurt to get a AC Outlet Tester to ensure the wall outlet is properly wired and grounded to Earth ground. I recommend one with a GFCI (ground fault circuit interrupt) indicator as it can be used to test bathroom and kitchen outlets (outlets near water) too. These testers can be found for your type and voltage outlet, foreign or domestic, (like this one for the UK) at most home improvement stores, or even the electrical department at Wal-Mart. Use it to test all the outlets in the home and if a fault is shown, have it fixed by a qualified electrician.

 

[Estaric]

Impossible to tell right now. Note intermittent problems that cannot be duplicated at will are the hardest to troubleshoot.

For sure, I would make sure the OS, your security, and particularly the graphics drivers are current. Make sure all data and power cables are securely fastened. Ensure the case interior is clean of heat-trapping dust, all fans spin freely, you have a good flow of cool air through the case, and all temps are good.

If the problem recurs, consider swapping in a spare power supply. Also, swap in a spare monitor. If the problem continues with the 2nd monitor, you will know the fault is on the computer side. If the problem goes away and stays away, the problem is likely in the monitor. It could be revealing if you could try that monitor on a second computer.

Im pretty sure I can 100% safely say the issue was not related to my pc as the flickering persisted with multiple devices and even when nothing was plugged in.
My 2nd and spare monitor both worked no issue while plugged into the same pc as well.

 

[Bill_Bright]

Well, then, assuming this LG's cables are securely fastened, it looks like your monitor was the culprit.

Did these problems start right from the start when new? I note according to LG, the native resolution seems to be 2560:1080 with a 21:9 aspect ration. Yet when I look at your RX Vega 56 as seen here, that that is not one of the recommended resolutions.

 

[Estaric]

Well, then, assuming this LG's cables are securely fastened, it looks like your monitor was the culprit.

Did these problems start right from the start when new? I note according to LG, the native resolution seems to be 2560:1080 with a 21:9 aspect ration. Yet when I look at your RX Vega 56 as seen here, that that is not one of the recommended resolutions.

considering that even the 2080 ti doesnt have a 21:9 resolution under its recommended id assume its because tpu doesnt list them generally? Maybe its just me but im not sure how a gpu that can go up higher resolutions 2560:1080 would not have it as a "recommended" resolution.

 

[Bill_Bright]

I would assume TPU lists the information provided by published specs. And supported resolutions are just based on the maximum. Aspect ratios come into play. Regardless all LCD displays have just 1 native resolution that provides the optimal image.

 

[Ja.KooLit]

my monitor flickering was fixed by replacing DP cable. I used my old DP cable since I need atleast 2 m for cable management. The supplied one was only 1.5m. Out of nowhere, after 2 or 3 days of usage, monitor started flickering. I was so pissed that time since it was a new monitor. I almost called for exchange of monitor. Then I just tried to use the supplied cable, flickering stop. Put back old cable, flickering. Odd thing was my old cable does not cause any issues on my old monitor.

Anyway, I decided to buy a new cable, and already a week still no flickering. So apparently, or my conclusion is that since my new monitor is high refresh rate vs old monitor which is only 60hz, high refresh rate monitors are sensitive to cables.

So my suggestion is to try another cable

 

[silentbogo]

If you say only part of the screen was flickering, then it might be a lose ribbon cable inside the monitor.
29UM68 has a single controller chip, but two separate FPC cables going to corresponding half of the monitor. If one of them is loose or if the flex connector is slightly damaged or corroded, you may encounter flickering. It may also be a microfracture in the actual LCD, which is gonna be near impossible to fix (costs almost the same as the monitor itself). It happens sometimes on ultrawide, and large/curved monitors in general, if it has flimsy plastic chassis and the owner moves it around the desk frequently (not enough support to compensate for lateral stress). But that's rare, and you really have to abuse that monitor for it to happen.