LG 42LC7D ccfl bleed at top of screen.

[Shinju]

Hey all!

I got this panel in a non working state, it was 4 2200uf 10v caps and 1 1500uf 35v cap.


I replaced the 4 2200uf caps with 25V of the same uf and the panel came right on. I didn't change the 1500uf as it was an odd ball uf and I didn't have it. I was going to replace it with a 2200uf 35v but I ran out of those too.

I put in a order and will replace the 1500uf as soon as it comes in.

Anyway the panel came right on after those were replaced, when the tv was on the back lights were only on in a low illumination mode with no input as soon as there is a signal the back lights illuminate brighter.

At the top of the screen as you will see in the photo below there are 5 half rectangle shaped anomalies at the top of the panel. They to me look like backlight bleed but once the panel warms up after about 5-10 min they are 95% gone and all you can see at that point on white/lighter screens are very light shaded in the affected areas the picture looks great and it doesn't seem to be affected to much when these are visible when first turned on..

What causes this to happen? I also see this on a few Vizio LG LCD models.

Is this a bad panel or tab bond issues?

[tom66]

Re: LG 42LC7D ccfl bleed at top of screen.

Pretty common on these older LG panels if they've been off for a while. Just let it run for a couple hours normally and it'll go away permanently (until it's off for a week again.)

Not a fault just a "bug" with the design when it gets too cold.

I think it is some kind of distribution issue with the LC crystals in that part of the panel.

[Shinju]

Re: LG 42LC7D ccfl bleed at top of screen.

Awesome, Thanks Tom. I noticed the LG made Vizio GV47L I have does this too, not nearly as bad but its present at cold boot up and dissipates after a minute or two.

[tom66]

Re: LG 42LC7D ccfl bleed at top of screen.

One the ones I've had, it will be there if off for a week or so.
But once in daily usage it never comes back.