LG 42LE4500, Int No Backlights...

[Alastair E]

Re: LG 42LE4500, Int No Backlights...

Hmm--without a signal driving the t-con/screen--From a Mainboard--you cant tell if its any good anyway!
--lighting it up will tell you no more than glass-cleaner and a strong light/sunlight will!

[citywidetvtech]

Re: LG 42LE4500, Int No Backlights...

not to dig up old posts. Put I put a 10k Resistor on pin 16 to ground and the backlights have been on all day so far.

[Greasejunky]

Re: LG 42LE4500, Int No Backlights...

Seems to be a common fault with these sets, Backlights failing after a few minutes, then after a while, 2 sec to black....

Ive one of these sets, and have traced the fault to the LED Backlight Driver-board, which sits on the main PSU board--Its the small green one.....
It appears the controller IC on that board is faulty.

As a test--I pulled that green board off the PSU and checked to see if the main LED supply was still present--It was, although low at 79V

For a larf, I rigged this low supply direct to the LED strings.

The set works!--BUT has a dimmish lack-luster picture.....
--IF I could now alter the feedback loop to get the voltage to 100V (The correct value) we be in business!

Hi,

Thanks for your informative posts on this issue.
My 4500 is now doing the same and I too have narrowed this down to the ic. Now I'm not an electronics guru like many of you! I'm a lowly mechanic but I do enjoy fixing things and saving money!

I read your post with interest on removing the driver board and running a feed directly to the LED strips. As the tv is in the bedroom I would be perfectly happy with the lower brightness caused by the voltage drop.

Could you please give me some pointers on this so I can carry out this mod? Pictures would be perfect?

I can solder fine and follow tracks and read voltages etc.

Thanks very much

[Greasejunky]

Re: LG 42LE4500, Int No Backlights...

not to dig up old posts. Put I put a 10k Resistor on pin 16 to ground and the backlights have been on all day so far.

Would like to know more about this if possible?

[vinceroger69]

Re: LG 42LE4500, Int No Backlights...

not to dig up old posts. Put I put a 10k Resistor on pin 16 to ground and the backlights have been on all day so far.

can you remember what ic this was on thanks

[budm]

Re: LG 42LE4500, Int No Backlights...

I wonder if City is referring to the pin 16 of the IC (which IC?) or pin 16 of the connector (which connector?).

[vinceroger69]

Re: LG 42LE4500, Int No Backlights...

I wonder if City is referring to the pin 16 of the IC (which IC?) or pin 16 of the connector (which connector?).

yes thats what i was thinking too hopefully he may remember what he did and can up date the thread for us.

[budm]

Re: LG 42LE4500, Int No Backlights...

https://www.badcaps.net/forum/showth...552#post705552

[ReeceyBurger123]

Re: LG 42LE4500, Int No Backlights...

Its not the Ics that fail. Something else on the driver goes bad but cant find out for the life of me what it is