Washed out picture on LG

[dishdude]

Does anyone know what could be going on here? The picture is very washed out and has a blue hue to it. I've tried adjusting all the picture setting and just can't get the picture to look brighter or more natural.

[dishdude]

I think I found the issue, apparently the LEDs start to fail and cast a bluish/purplish hue.

https://www.youtube.com/watch?v=Fv15_yyo9dM

[JohnCT]

Common problem. There are two solutions: change every LED in the TV or find *new* strips (don't get any used or "pulls").

If you elect to change all the LEDs, you're going to have to expand the lands on the strips by scratching the mask back with a small screwdriver because the original LEDs are so tiny (and not available). Also, you'll need to replace every lens because your replacement LEDs won't fit under the original lens'.

You can use donor strips from a different brand as long as you stay with 3.3 volt LEDs and use the same total number so as not to piss off the IC controller. If you use strips from another brand, you probably will have to punch out holes in the white reflective barrier to match the lens spacing.

John

[dishdude]

Originally Posted by JohnCT

Common problem. There are two solutions: change every LED in the TV or find *new* strips (don't get any used or "pulls").

If you elect to change all the LEDs, you're going to have to expand the lands on the strips by scratching the mask back with a small screwdriver because the original LEDs are so tiny (and not available). Also, you'll need to replace every lens because your replacement LEDs won't fit under the original lens'.

You can use donor strips from a different brand as long as you stay with 3.3 volt LEDs and use the same total number so as not to piss off the IC controller. If you use strips from another brand, you probably will have to punch out holes in the white reflective barrier to match the lens spacing.

John

Thanks for the info. Can you recommend a good source for new strips?

[JohnCT]

Originally Posted by dishdude

Thanks for the info. Can you recommend a good source for new strips?

If you're not in a hurry, then Aliexpress. Otherwise, ShopJimmy may have them as well. Don't forget to check ebay, but make damned sure these are not pulls! Even working strips will have some LEDs just starting to turn blue (slow progression).

Replacing all the LEDs individually is time consuming and there's a bit of a learning curve involved, plus you'd need a big bag of donor lens (I have thousands). Upside to this is that it costs virtually nothing. Downside is that it takes a lot of time and precision alignment of the donor lens.

Put your model number in the ShopJimmy website, and if they have the strips, you can get them there. They will also have high res scans of the strips so you can often use those numbers to check with Aliexpress if you don't mind waiting 3-4 weeks.

If you do replace the strips, be ****very**** careful putting the screen back in the plastic guides. If one corner is just a smidge over the frame, it will crack when you snap on the outer bezel.

If you do get new strips installed successfully, send me the part number of the power board and I'll tell you how to modify the drive current to the strips that will extend the life of them by at least 4X minimum.

John

[dishdude]

Thanks for all the detailed info.

[kf4rca]

Haven't seen any of these to hit the roadside... yet. I would have guessed TCon board too.
Surprised they decided to go with smaller LEDs. Certainly reducing the size compromises reliability.
I was hoping someone would come out with a design that would allow LED replacement from the back panel.

[dishdude]

I was thinking TCon board when I first saw it too. It's the TV in my Mother's bedroom, about 4 years old but she runs it 24/7 so I'm sure it has a ton of hours on it. I don't live in the area and this is the first time I've seen it since the pandemic.

Planning to return next month and replace it, I'll bring it back with me and swap the LEDs with strips from Alliexpress and post my results.

Funny thing is, she doesn't think there's anything wrong with it! Just like the old days when people would somehow not notice they lost one of the guns in their CRT.

[JohnCT]

Originally Posted by kf4rca

Surprised they decided to go with smaller LEDs. Certainly reducing the size compromises reliability.

Strangely, the tiny glass chip LEDs don't fail like most (either open or short). They continue to operate just fine. The problem is that the phosphor added to the LED (which has a natural blue color) burns off with continued use. The diode junctions themselves are remarkably stout. I'm sure they thought these tiny chip LEDs would fix the LED issue.

Originally Posted by kf4rca

I was hoping someone would come out with a design that would allow LED replacement from the back panel.

There actually is one. There's a 75" TCL that uses an edge lit system, and the LEDs are available at the bottom of the screen under the address boards and can be replaced without touching the screen itself. As long as you don't knacker the flex ribbons, you should be OK.

John

[kf4rca]

Haven't seen any edge lit screen sets hit the roadside yet.
So I suppose I should be harvesting the LED strips from these cracked screen sets since field repair of the strips is no longer possible.

[YamahaFreak]

Originally Posted by JohnCT

If you're not in a hurry, then Aliexpress. Otherwise, ShopJimmy may have them as well. Don't forget to check ebay, but make damned sure these are not pulls! Even working strips will have some LEDs just starting to turn blue (slow progression).

Replacing all the LEDs individually is time consuming and there's a bit of a learning curve involved, plus you'd need a big bag of donor lens (I have thousands). Upside to this is that it costs virtually nothing. Downside is that it takes a lot of time and precision alignment of the donor lens.

Put your model number in the ShopJimmy website, and if they have the strips, you can get them there. They will also have high res scans of the strips so you can often use those numbers to check with Aliexpress if you don't mind waiting 3-4 weeks.

If you do replace the strips, be ****very**** careful putting the screen back in the plastic guides. If one corner is just a smidge over the frame, it will crack when you snap on the outer bezel.

If you do get new strips installed successfully, send me the part number of the power board and I'll tell you how to modify the drive current to the strips that will extend the life of them by at least 4X minimum.

John

I'd be interested in that lifespan-lengthening mod. Does it work for most/all makes? I'm seeing an increasing number of LED backlight sets with failed LEDs.

[dishdude]

Originally Posted by YamahaFreak

I'd be interested in that lifespan-lengthening mod. Does it work for most/all makes? I'm seeing an increasing number of LED backlight sets with failed LEDs.

Thanks for bumping this thread. I'm picking the set up next week and was planning to ask the same question. I've also been seeing a lot of sets with this failure recently now that I know what to look for.

[YamahaFreak]

Originally Posted by dishdude

Thanks for bumping this thread. I'm picking the set up next week and was planning to ask the same question. I've also been seeing a lot of sets with this failure recently now that I know what to look for.

Not a problem! :P