Author Topic: Lg 43uh620v blue leds  (Read 609 times)

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sinclairtv

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Lg 43uh620v blue leds
« on: November 04, 2018,06:53:40 »
Got in one of these sets with picture that looked like a lack of green. Customer bought another so I took it to bits to check leds. Strip no is uf64_uhd_a. I prised lid off of one to see and it's tiny and bright blue. Photos enclosed but not great.

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Lg 43uh620v blue leds
« on: November 04, 2018,06:53:40 »

downunder

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Re: Lg 43uh620v blue leds
« Reply #1 on: November 05, 2018,04:33:00 »

There are mentions of this on-line for this model, no detailed cure other than hinting it'd be cheaper to buy a new tv.

Bruce

sinclairtv

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Re: Lg 43uh620v blue leds
« Reply #2 on: November 09, 2018,06:31:56 »
Update. Replaced every led. Solved the problem though I can now see leds shining through as I hard wired them on top of existing strings. Must have been manufacturing fault though goodness knows how every led went blue.

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Re: Lg 43uh620v blue leds
« Reply #2 on: November 09, 2018,06:31:56 »

Turnip

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Re: Lg 43uh620v blue leds
« Reply #3 on: November 12, 2018,12:16:37 »
Hi Sinclair,

Replacing every Led is pretty nifty, especially when hard wired to existing strips - Guess you do it as you can.

Suspect new Led lenses nearer the screen than originals. Might be an issue as even original ones give trouble if not replaced exactly as they were.

Note that using clear adhesive causes lenses to give issues as modifies light dispersion giving bright screen patches.

Trying sort a non-clear adhesive, guess White, as anything else gives trouble - Chris.

downunder

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Re: Lg 43uh620v blue leds
« Reply #4 on: November 14, 2018,03:10:16 »

Well, kudos to you, Sinclair. That's how I replace dud LEDs. Clean off the dud and then snip off a piece of strip with a good LED on it. Solder this in place with short wires so it can be located in the hole of the white reflector sheet. Getting quite good at it now. No tiny LEDs slipping away never to be found again and no lens cap to align.

Can't say that I've had a problem with light spots even though the new LEDs are fractionally closer to the screen. The LGs with the chunky lenses are worst for this and 90% of them drop off if you lightly touch them.

Bruce

sinclairtv

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Re: Lg 43uh620v blue leds
« Reply #5 on: November 16, 2018,14:58:27 »
These blue LEDs were tiny so no chance to replace them. I usually break them with cutters, then melt some solder on them till they can be scraped off, then keeping the lens in alignment, replace the LEDs. I only hardwired these as an experiment when I had 3 hrs to spare lol

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Re: Lg 43uh620v blue leds
« Reply #5 on: November 16, 2018,14:58:27 »

Turnip

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Re: Lg 43uh620v blue leds
« Reply #6 on: December 01, 2018,09:56:10 »
Hi Folks,

Just got a Sammy UE32J5100AK where the Leds are Blue RHS but nearly normal LHS with a gradual colour shift between.
Guess at some point replace Leds individually, but in the mean time, strips from an Ebay screen smash.

Wonder why a Led changes colour ? - Chris.

Later - Took the screen off finding 8 S/C Leds and the Blue ones had shed the usual Yellow coating as perhaps got a little hot.
« Last Edit: December 03, 2018,09:35:35 by Turnip »

sinclairtv

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Re: Lg 43uh620v blue leds
« Reply #7 on: December 29, 2018,05:54:21 »
This is going to get more common as iv now got same blue leds in a jvc. Put 17dlb40vxr1 in ebay and there's a regular seller selling replacement and different leds for these strips. Dunno if it's worth the hassle as you'd probably be better replacing them all.

Turnip

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Re: Lg 43uh620v blue leds
« Reply #8 on: December 29, 2018,10:18:15 »
Hi Sinclair,

Guess you're right, have a Sammy UE40J5100AK where those little Leds keep popping off even before they turn Blue. Changed a couple, and set back in a month with more gone. Thought to reassemble, then found four more flickering using the tester.

Note Ebay does 100 x A137CECEBP18A for a Tenner, and they look like the originals, so you could sort a couple of pretty big screens or several smaller ones with a hot iron in each hand.

Trying suss something, where with small spots of solder paste, can sort soldering, heating the back of the strip. First try, used too much paste and the Led popped off somewhere, never to be seen again. Now sorted a bit of aluminium channel, a metal clad 3R3 50 watt power resistor and a 250C cut-out - Might work with a 12v 4a supply, or not.

 

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