Repeat LED failures on 65UH5500

[jjanssen7]

I have repaired 6 or 7 of LG's 65UH5500 all with LED failure. In each case, I've found one strip that has failed. When I replace the failed strip with one from a brand new/cracked screen unit, the TV works for a while and then eventually comes back after a month or two with a DIFFERENT failed strip (in a different spot in the grid). Never the one I replaced, always in a different spot.

Anybody have experience with this problem with this model? I have more of these TV's to repair but there is no point in replacing strips if the TV keeps coming back because the "next" weakest strip has failed. Is it possible that the LED controller is over driving the LEDS (beyond the usual LG LED failures) and burning them out prematurely? (I have had the same experience with the 55UH5500 version of this TV and so have stopped repair those until I come up with a permanent fix).

Any thoughts on what I'm missing?

[nomoresonys]

Re: Repeat LED failures on 65UH5500

https://www.youtube.com/watch?v=ogtfojsIZK8

[nomoresonys]

Re: Repeat LED failures on 65UH5500

Another example, there's probably videos that explain the details in depth, just a matter of locating them: https://www.youtube.com/watch?v=2G_PB2-Ki8Q

[Wilderone]

Re: Repeat LED failures on 65UH5500

Are you turning the backlight level down on all inputs?

[neilc6]

Re: Repeat LED failures on 65UH5500

On any LG I replace strips on, I make sure the owner keeps an eye on the backlight level and runs them at 50 to 60%. They need to check every input and every app (youtube, netflix, media player). I only have had a few come back out of dozens (mainly LN series but a few LA and LB). With the LN smart apps, backlight setting can only be adjusted from the quick menu remote button which makes it trickier to find. Eco mode should be off (cranks up backlight in bright room). Default setting is 100% for standard picture mode and 70% for eco picture mode which is still a bit high.

[jjanssen7]

Re: Repeat LED failures on 65UH5500

Yes, I have tried turning down the backlight levels in the menu, firmware upgrades.

I'll have to investigate modifying the LED current. This model is different than the LN/LA series in that only one LED is burned out... often when I repair the LN/LB/LA series they have multiple strips burned out. Usually one strip shorted and 5 or 6 others burned out but not shorted. That's what made me wonder if something else might be going on.