Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

[Cgreen]

Hey new to this forum, but active member of several automotive forums.
Can someone please tell me the source of this problem that started about 3 days ago. It is a 55 in LG model #55LS4500 it has developed a horizontal shadow in the middle right side of the screen. There is still a picture in the area it is just darker, shadowed.
I have repaired several tvs in the past . Mostly caps,dlp chips and t-con boards. But I don't know where to start troubleshooting this one.
The odd thing is when I first turn the TV on the shadow is not there, then approx. 3 seconds later the screen dims slightly and the shadow appears.
Is it the led strips?..a board??..caps??. Any help would be appreciated.
It looks way worse in the pics than it looks in person but still it is annoying.

[dick_barton]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

It's an edge lit led set so I suspect some of the leds have failed.

[budm]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

You can take some Voltage readings:
https://www.badcaps.net/forum/showthread.php?p=660257
What happen if you turn down the backlights level to very low but still able to see the pictures?

[Cgreen]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

If it went out would it still work when I first turn it on then go back out. That's the weird thing, I thought when a led quit....it quit.. this one works for like 3 seconds. Then the shadow appears.

[Cgreen]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

I have searched and searched the forums and net and found tons of info on black bars and other common issues. I just haven't found one post with a pic that looks like my shadow

[dick_barton]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

Turn down the backlights as BudM suggests and see the results.

[Cgreen]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

You can still see it with backlight on 1. Here is a pic just now of it when
It first comes on.. No shadow.. then 3 seconds. Later it appears.

Well you can kinda see it start to form. It took a sec. For my camera to take the pic.

[Cgreen]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

Here is one timed correctly,

[budm]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

Backlights (not Brightness level) level at 1 should be very very dim. I say you have bad LEDs that are dying. If you test the Voltages at those test points in the link, it should show some not normal reading.

[Cgreen]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

Yeah the screen does get very dim with the backlight set at 1 but you can still see the shadow.
Where can I buy the led strips if that turns out to be the problem.
I went on ShopJimmy.com and they don't list any replacement leds for the 55ls4500.
Is there a way to cross reference parts that will work or a better site to look for them?

[Cgreen]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

As far as taking readings...I'm kinda what I refer to as a "parts changer". I can disassemble any TV and swap parts out, just not versed in taking readings on normal parameters.
I am a professional Firefighter that tinkers with electronics. Please excuse my lack of electronics knowledge.

[budm]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

I believe this TV uses edge lit LED assemblies, not the usual back-lit setup. I need to look up the spec.
Yep, it is Edge lit:
http://www.lg.com/us/tvs/lg-55LS4500-led-tv

[Cgreen]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

Can I buy those? So I can just swap them out. If so where?

[budm]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

Look at the model number sticker of the LCD panel then you may be able to find info about the replacement LED assembly for that panel.
The hardest part will be taking the panel apart without breaking the LCD Glass panel, you should also test the new LED assembly first by connecting them to the board without taking the panel apart in case you get bad assemblies.

[Cgreen]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

So you are saying that I can't just disassemble the TV and replace the edge led unit.....it is inside the display panel??.
My ultimate question is, would you attempt this or just buy a new TV?

[budm]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

So you are saying that I can't just disassemble the TV and replace the edge led unit.....it is inside the display panel??.
My ultimate question is, would you attempt this or just buy a new TV?

You need to disassemble the LCD panel to get to the LED assemblies, that 55" Glass panel is very thin and can easily be broken. I and other here have done the repair down to the inside of the panel, if you have never done it before then it is not going to be easy for you.

See example:
https://www.youtube.com/watch?v=axmZJBRGYn4
https://www.youtube.com/watch?v=qGk6Nx82SCA

[vinceroger69]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

This video will give you a rough idea how hard it is too do although this set looks like a 32 in and yours is 55 in this video uses ccfls and yours uses led on the edges instead but it will give you a idea what you need too do.
https://www.youtube.com/watch?v=axmZJBRGYn4

[Cgreen]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

Thanks I watched the videos. I can do that (providing I don't break the glass with it being so big). I really hope I can find replacement parts fast after I tear it apart. I was hoping this fault was common and someone could tell me what part to order right away. (Less TV down time). But like I said ShopJimmy.com doesn't even sell the led parts for this model.

[budm]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

So did you find out what LCD panel make, model, and the revision number of the LCD panel to be sure to get the correct LED assemblies for it? Same TV model can have more than one panel model being used, verify, verify, and verify.

[Cgreen]

Re: Please Help with LG 55LS4500. DARK SHADOW ON SCREEN

I will have to get those numbers tomorrow when I tear it down. Once I have the numbers...What source do you experts use for parts? I'm hoping ebay is not my only choice, as they don't have many parts for my TV listed right now. There are some edge led assemblies on there now, but for different model TVs.