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Old 10-18-2019, 04:16 PM   #1
neilc6
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Default LG 49UJ6500 Blue Blacklights

Check this out. LEDs have turned blue. TV is only 2 years old. Owner doesn't know history since they bought it used so could have been store demo. Ordered the wrong strips since there is a panel version that uses 3 rows of strips. Only two rows on this one for a 49 inch TV.
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Last edited by neilc6; 10-18-2019 at 04:42 PM..
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Old 10-19-2019, 06:00 AM   #2
FrozenHaxor
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Default Re: LG 49UJ6500 Blue Blacklights

What the? Is this some bizzare LED aging? I have seen LEDs that turn greenish after overheating but this is extreme. Maybe it has some special diffusion filters that change the light wavelength?
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Old 10-19-2019, 08:52 AM   #3
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Default Re: LG 49UJ6500 Blue Blacklights

Probably overdriven, definitely worn out and turned blue. The yellow phosphor wears off and blue is left.

Last edited by nomoresonys; 10-19-2019 at 09:06 AM..
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Old 10-20-2019, 11:23 AM   #4
imran333
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Default Re: LG 49UJ6500 Blue Blacklights

Lg or other vestel brand leds have a problem where some or all leds turn blue and itís just bad leds they use, I had the same problem in hitatchi and LG tv where some are blue but the picture was fine and I only noticed as I was stripping tv for parts but I canít sell the backlights as they are faulty , pictures attached
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File Type: jpg 589B08DE-65F7-4938-9F3C-5BFB12EE9374.jpg (379.9 KB, 12 views)

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Old 10-20-2019, 01:38 PM   #5
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Default Re: LG 49UJ6500 Blue Blacklights

Over voltage causes LEDs to change colors and is permanent.
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Old Yesterday, 04:31 PM   #6
neilc6
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Default Re: LG 49UJ6500 Blue Blacklights

Got a second LG in with blue backlights 43UJ6300. Popped off the lens this time and it appears there is a yellow filter (see this yellow in all previous LED backlights) that has crumbled away exposing the naturally blue LED underneath.
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Old Yesterday, 05:40 PM   #7
nomoresonys
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Default Re: LG 49UJ6500 Blue Blacklights

Quote:
Originally Posted by neilc6 View Post
got a second lg in with blue backlights 43uj6300. Popped off the lens this time and it appears there is a yellow filter (see this yellow in all previous led backlights) that has crumbled away exposing the naturally blue led underneath.
bingo!!!
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Old Yesterday, 05:58 PM   #8
budm
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Default Re: LG 49UJ6500 Blue Blacklights

They are driven so hard so they fail and LG knows it.
LED failure mode:
https://www.dfrsolutions.com/hubfs/R...Mechanisms.pdf
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Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956

Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999

Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl

Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/

TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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