LG 55LE5500 with main board EBU60904803

[jason123]

I'm hoping someone came across this issue.. I have an LG 55LE5500, that all of a sudden went blank (backlight is on, but no picture), audio is ok all other controls seem to be working. When you look at the screen you can almost tell there is a divide (though not a vertical line) between left and right.

The main board on this unit is both controller and Tcon in one, expensive and not available. Reseating cables, didn't improve things. Voltages on the connector to / From Power board are all within spec +/- 1 or 2 %

Is it worth pursuing sending the main board for repair? or is there a way to find out if it's a bad panel?
Thanks

[jason123]

Re: LG 55LE5500 with main board EBU60904803

So, I sent board to PTS Electronics for repair.. they said they can't find a problem with the board and they ran it overnight, and it's working fine on their set (I'm assuming - they just said they can't find a problem)

Does this suggest I have a bad panel? I'm taking the panel apart and I'm doing spot checking on the LVDS Panel connector / board (Bottom Left) and I'm finding many caps that are shorted.. These are ceramic caps.. either they're shorted, or the panel is.. no way to know without removing them. Anyone know where I can find a schematic for these boards? LC550EUB Right Source_V5 - P/N 6870S-1011A

[JeffJ]

Re: LG 55LE5500 with main board EBU60904803

Are you sure the blights are actually on? this model and similar are well known for the back lights failing and causing your issue.

I have the next model above this, the leds failed not once but twice 4 months apart. Lg eventually released firmware that "fixed" this issue but now i sit on a tv that no leds are available for because the use market does not have a single set that works.

[jason123]

Re: LG 55LE5500 with main board EBU60904803

Hi JeffJ, yes, the backlight is on - I agree with you, when I bought it, I thought it was a quick edge light strip repair like the ones I've seen before .. but that's not the case unfortunately.

[jason123]

Re: LG 55LE5500 with main board EBU60904803

Just a quick update.. I know this is something rare, but it turned out there is a ceramic capacitor (10 uF) on the panel boards (the skinny boards that the LVDS cables from Tcon / Main card connect to) that was shorted.

Replacing that, took care of the problem.
Thanks

[vinceroger69]

Re: LG 55LE5500 with main board EBU60904803

Thanks for the update im sure the information may help others users too.

[budm]

Re: LG 55LE5500 with main board EBU60904803

Great job finding the cause of the problem.
If you can post the picture of the bad cap that will help other people as well.

[jason123]

Re: LG 55LE5500 with main board EBU60904803

Sorry it took a while.. but here are some photos that will show the bad component. Replaced with a 10 uF X7R @ 16 V

[dick_barton]

Re: LG 55LE5500 with main board EBU60904803

Excellent find. Good feedback.