Hi all i changed all the strips on an lg 42lb5500 led tv and now i can see a very slighter row of darker circles that match up to the position of the led lens covers,is there any way to remove this?.Im pretty sure that these tvs had this problem when they were new?.The tv works fine and i cant really do anything about this.Maybe it was the quality of the strips i bought on ebay?.Any thoughts?,thanks for your opinions and advice in advance.
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Re: Lg 42lb5500 backlight bleed (dark circles)
Wonder if you got a mismatch on your replacement strips or faulty ones, does it help to turn down the backlights if possible?Quit because THIS SITE LETS A ROGUE MEMBER TYPE ANY GARBAGE HE PLEASES AND THE POWERS THAT BE NEVER DO ANYTHING ABOUT IT SO HE NEVER QUITS. THEN YOU GET A PENALTY FOR RESPONDING TO HIS ATTACKS. BEEN GOING ON FOR WAY TOO LONG. DONE SUPPORTING A SITE THAT ALLOWS THIS BS. -
Re: Lg 42lb5500 backlight bleed (dark circles)
Hi no turning down the backlights does not help at all i'll attach an image the strips i ordered are the same type as the ones in the tv originally as you can see the leds leave a very slighter darker spot where each led lens is.Thanks for your help by the way nice of you to reply.Attached FilesComment
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Re: Lg 42lb5500 backlight bleed (dark circles)
I suspect diffuser layer fault , eg wrong orderComment
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Re: Lg 42lb5500 backlight bleed (dark circles)
I put them all back in the same order they came out (i think,lol),im pretty careful with that sort of thing normally to be honest but thats a good point there is a slim chance of that but i think its a bad batch of led strips with the incorrect lens angle fitted to the lg originals..Comment
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Re: Lg 42lb5500 backlight bleed (dark circles)
Because they are all noticable i doubt that all the strips were faulty manufacture
Have replaced many of this tv with new one and never had any issues
I stand by my first evaluation that the diffuser panels somehow got messed up
When i do these TV i tape the diffusers together and remove together , they can be slippery buggers and you can easily ether get the sequence mixed up or one of the diffusers reversedComment
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Re: Lg 42lb5500 backlight bleed (dark circles)
Thank you i think i will tape them together myself as you do in future to assure i don't make the same mistake again i have took this tv apart a couple of times now in the past so its likely that the sheets did get mixed up or one the wrong way round etc,thanks everybody for your input,very kind of you all to help.Comment
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Re: Lg 42lb5500 backlight bleed (dark circles)
This type of circles can appear as a result of the diffuser panels not sitting the correct distance from the LED lenses on the LED strips.
I have seen many TVs lately where the delicate plastic spacer clips that hold the diffuser panels away from the backlight LEDs are bent or damaged and the diffuser panels can warp and sit however they want... This means some areas are closer to the LEDs and some areas are further away... Areas that are closer will not have adequate spacing to diffuse the light from the LEDs and will appear as spots.
Check those delicate plastic clips, or ensure you did not damage them when you removed them, and certainly make sure that you put them back in place (or didn't lose them or damage them)
Depending upon their install location, you may even have different length clips... It is important to re-install exactly so all areas are held the same distance from backlights.
It's hard to tell, but the center areas of the screen look worse than the outer areas so your diffuser panels and LCD may be warped toward the middle of screen (ie, unsupported in middle area)
One other thing to check, is if all your diffusers are installed in the correct order and all your clips are correctly installed.... Maybe your metal backing of the panel is WARPED. Sometimes this can happen if excess weight or pressure is applied to the metal panel when resting face-up on the operating table (try not to lean on it if you are reaching because it is thin gauge material that is prone to bending)Last edited by Unspun01; 04-29-2019, 10:01 AM.Comment
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Re: Lg 42lb5500 backlight bleed (dark circles)
Thats a very good point about the metal back might have got a bit warped i never thought of that,ill make sure i don't put too much pressure when operating on the tv metal back and removing and installing the new led strips.Thanks for your input.Comment
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Re: Lg 42lb5500 backlight bleed (dark circles)
Also you're correct the shadows were worse in the middle of the screen....Comment
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I bought this p2210f dell monitor to fix. Schematic is the same as p2210.
Behaviour is that monitors comes on but then backlight switches off almost instantly. If I look with flashlight I can still find the "No signal message". So definitely a backlight issue. Trying to advance the issue I proved that the protection circuit is switching off the backlight by shorting out C3 and resistor to disable the INL chip then re enable by removing the short.
This is where it gets interesting. When I disassembled the monitor to solder leads on c3 capacitor I noticed the backlight flickered... -
Hello all,
Am trying to figure out this backlight issue with this A1990 Macbook Pro.
Tests performed:
There is no backlight even with a good screen.
Backlight IC is receiving the correct support voltages.
Fuse F8400 ok
Current sense resistor R8400 ok
Backlight IC is receiving 3.3V on enable pin.
Backlight IC receiving voltage from PPBUS_G3H, aprox 12.5V.
Backlight IC receiving 5V from PP5V_G3S
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Hello, got an iPad Pro A2378 12.9 5th gen with no backlight. Got another test unit without screen, tested the screen, still no backlight with the test unit.
Figured out the backlight on the screen was bad, ordred a new backlight from mobilesentrix, *carefully replaced it* without damaging the lcd, oh well.
Final result, issue is still there, the screen has no back lights. So i'm back to square one, with 3 hours less and 100$ out, issue still on the screen.
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Anyone... -
Ok.. this is the story:
Have an old Samsung LED 3D TV (UE55F6475). First it started to lose light on the lower 40% of the screen now and then. Like for 10-60 mins and then it would work again. Then a bit later it just got stuck in that position. The lower 40% of the screen is dark, and it gets progressively darker the lower u go so it's obviously that LED strips where not working. I also looked for similar errors online and saw an exact copy and on that one it was faulty LED strips.
This is kinda how it looked, just that mine were at the bottom of the screen:
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Hi all,
I've got an LG Flatron 24EN33TA with a backlight issue. The problem began with the monitor not powering up after sitting for a long time (overnight or during the day throughout work). When I would wake the computer up, the backlight would flick on for a second then go out. Sometimes it would take many tries to get it to come on. Once the monitor came on, it worked flawlessly until another long duration of being powered off.
I thought the problem would be bad caps but I checked both of the caps on the board and they are fine. I also tried powering the monitor from...
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