EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: akis on February 19, 2019, 08:34:10 pm
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My LG 55" OLED TV has suddenly started to misbehave - there are "smoke clouds" that have appeared on screen. Most visible on plain backgrounds of a light colour. I attach two pictures and have highlighted the areas, This is the TV doing that, it's on the Settings screen, Amazon, Netflix etc.
PS: the wall behind the TV is off-white but my phone camera thinks otherwise...
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Iv seen this kind of 'bruising' on older LCD TVs before, usually appearing with age. no experience with oleds
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Don't LG OLEDs have some sort of 'screen equalize' or 'condition screen' option in one of the settings menus? I'm not sure of the exact term, but I remember seeing it on my son's LG - from the look of the stand I think it may be the same model.
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OLEDs can suffer from a form of 'burn in' where pixels that are lit in a uniform intensity for long periods of time become less able to transmit their full gamut of light.
This is usually from logos or ticker type scrolling displays that leave a shadowy look of the original image on the screen.
This effect on your screen would need something bright in that shape on the screen in those areas for long periods of time. It almost looks like some sort of physical damage like a hand grip or physical pressure has been applied.
Sorry, no solutions.
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I ran the in-built "pixel refresher" takes an hour and the TV is off - and the problem went away.
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Pixel refresher, that was it.
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As an owner of an LG OLED that's interesting. Any idea how the 'refresh' is achieved? Is some change made to each pixel LED or is it a drive calibration?
BT
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At a guess there must be a system/algorithm that modifies/modulates the intensity of pixels based on their calculated luminance, and the algorithm over a period of time probably needs a "calibration"... Very wild shot.
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Or it’s not actual burn-in, but rather other temporary image persistence, like what happens on LCDs and plasmas. (I don’t know the exact mechanism in LCDs, but in plasmas it’s a buildup of charge.)
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If you read earlier in the thread, the built-in pixel refresh function resolved the issue - no point in taking a fully working TV to a repair shop.
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OLED's are top emission LED's. Meaning the y live on the surface. If they got pressed in by some hands and that may be causing the UN-evenness.
If that is the case there will be NO repairing it. |O the screen would be permanently damaged in that scenario.
That being said it looks to me like smudges of grease or oil on the screen.
did you try cleaning it? glass cleaner will work.