I purchased two 5K Ultrafine displays in 2017.
One of the two 5K displays stopped working in February of 2019. The unit received power but had a black screen/blank screen. I sent the display to LG for repair. They replaced the panel for $150. It took well over a month to get it back (maybe closer to two months). One and a half years later, it still works after the repair, but it has retention issues and pretty bad burn in.
The second of my two 5K display stopped working in June of 2020. I called LG about getting it repaired. I expected to spend $150 for the same repair I had done to the first 5K display and for it to take a month or two to repair this second display (just like with the first).
Nope:
After weeks of contradictory messages from multiple chat, email, and phone reps, LG finally told me definitively they no longer support the 5k Ultrafine Display and would not repair it. They said I would have to bring it to a local repair shop to get it fixed. They have a list of authorized dealers and recommended the closest one to my location.
I brought the 5K display into the local repair shop. A week went by and after I called for an update, they told me LG said it was probably a firmware issue. I explained that I have two identical 5K Ultrafine Displays, both on the same firmware, and one works while the other doesn't.
"This is not a firmware issue," I said. "The unit receives power when connected, but there is no picture. The same exact thing happened to my other 5K Ultrafine Display. LG replaced the panel on that one and it worked fine. I'm sure if you replace the panel on this display, it will work."
After 3 more weeks of hassle, they finally told me they talked to LG, and LG said they no longer support the display and they could not get what they needed to repair the display and that I was sore out of luck.
I now need to go pick up my still-broken 5K display after 2 months of no one being able to repair it.
Does anyone know where or how in the world I can get this thing fixed?