LG UltraFine 4K display randomly flickering
June 29, 2026
June 29, 2026
I have a LG UltraFine 4K monitor (24MD4KLB-B, the one made in partnership with Apple in 2019 for deep macOS integration).
This year it randomly started flickering. Literally once second it was OK, and the next it was flickering. It’s been plugged the same way for years (I use it with a Lightning cable on my MacBook, which also powers the laptop). Nothing changed.
Tried a bunch of things including unplugging and re-plugging the display, both from the laptop and from the power outlet, as well as restarting the computer. No change.
Flickers varies from the whole screen flashing black at a fast rate, or some specific portions of the screen flashing with more of a “noise” pattern? And more recently, ghosting of what I had on screen at the time it started flickering.
The only report I found is this Reddit post but sadly no solution there (until I posted mine more recently).
The only thing that seems to reliably fix this for me is to plug the laptop with a power adapter, instead of relying on the screen to power and charge it.
It’s not instant but it seems after leaving the computer plugged for a few minutes or sometimes a few hours, the flickering is gone.
Then you can use the screen for power again, and in my experience it’s fine again for weeks or even months until the next instance of flickering. 🤷
Hi, it’s Val from the future, a month later. It just happened again and the previous solution wouldn’t do anything.
Tried unplugging the monitor overnight, but this changed nothing.
Tried LG Screen Manager to update the monitor software, and to factory reset the monitor, but both changed nothing.
Then in a Google search for “LG UltraFine 4K flickering” which lead to a quick back and forth with Gemini, it eventually suggested one thing I hadn’t tried yet: force an internal panel flush.
Since the ghost frame survived overnight, The LCD pixels are physically stuck in their twisted orientation due to a static electrical charge.
How to do this? Play a “pixel unsticking” or “color cycling” video, also known as “LCD screen burn-in fix”. I searched exactly that on YouTube and found this video (one amongst a ton of other similar videos).
I played it, full screen of course, for a couple hours and guess what, I returned to a perfectly fine screen, no flickering and burn-in anymore!!