LG 55LB7200 - Bad LED backlights or panel?

[bobbyskillz]

Hey, guys! I picked up this set last night. The owner complained the picture would turn off after various lengths of time, but the sound would persist. I think I'm looking at two bad LED strips. In previous sets I've worked on, a single LED failure caused the whole backlight to turn off. Is it possible only certain strips are failing here?

I've not come across the mura effect yet. Could this be the issue? I also noticed temporary image persistence after sitting in the menu for some time.

I attached a picture of it on a solid white screen.

Thanks for your opinions!

[Michale32086]

Re: LG 55LB7200 - Bad LED backlights or panel?

Yea, it looks like you have 2 bad half-strips and a possible 1 or 2 LEDs..

I am assuming you are using an LED Power Supply to get the LEDs going??

It's been my experience that, especially with LGs, you can have 1 bad LED and, depending on it's position, it can take down the whole array...

[bobbyskillz]

Re: LG 55LB7200 - Bad LED backlights or panel?

Yea, it looks like you have 2 bad half-strips and a possible 1 or 2 LEDs..

I am assuming you are using an LED Power Supply to get the LEDs going??

It's been my experience that, especially with LGs, you can have 1 bad LED and, depending on it's position, it can take down the whole array...

Thanks for the reply! I didn't take the first screw out yet. The TV works - but with the dark spots (and that temporary image persistence). I just used a solid white video to better see the situation.

I guess I'll pull the unit apart this weekend and replace some LEDs.

[Michale32086]

Re: LG 55LB7200 - Bad LED backlights or panel?

Thanks for the reply! I didn't take the first screw out yet. The TV works - but with the dark spots (and that temporary image persistence). I just used a solid white video to better see the situation.

I guess I'll pull the unit apart this weekend and replace some LEDs.

See my post here:

https://www.badcaps.net/forum/showthread.php?t=80430

for some caveats on removing the panel display panel..

I would also invest in a pair of items pictured..

Harbor Freight has them..

They will save you a WORLD of heartache..

[bobbyskillz]

Re: LG 55LB7200 - Bad LED backlights or panel?

See my post here:

https://www.badcaps.net/forum/showthread.php?t=80430

for some caveats on removing the panel display panel..

I would also invest in a pair of items pictured..

Harbor Freight has them..

They will save you a WORLD of heartache..

Thanks! I've just got two single large suction cups I've used from Harbor Freight. The doubles with the handle definitely look better. I'll probably stop for them later.

My most worrisome times are always lifting the panels and hoping not to drop them when I move them away from the set.

[Michale32086]

Re: LG 55LB7200 - Bad LED backlights or panel?

Thanks! I've just got two single large suction cups I've used from Harbor Freight. The doubles with the handle definitely look better. I'll probably stop for them later.

My most worrisome times are always lifting the panels and hoping not to drop them when I move them away from the set.

Heh Yer preaching to the choir on that point.. I use the single-suction ones for small panels less than 42" Anything larger the dual-suction ones are a must.. Have yet to drop a panel using the dual ones.. When you un-suction them, pull the lever back to release position gently.. Don't snap it back... Learned that the hard way...

"To answer that; human beings have neither the aural nor the psychological capacity to withstand the awesome power of God's true voice. Were you to hear it, your mind would cave in and your heart would explode within your chest. We went through five Adams before we figured that one out."
-Metatron, DOGMA