Oh 55LE5500 panel tab

[splatee]

We'll probably against my better judgement I picked up this tv off Craigslist with a vertical white bar and colored lines for $20. Pop it open and looks like part of the board where the ribbon tab cables connects to is scuffed up and the ribbon tab cable itself gets very hot compared to the others. It looks like there is some sort of resistor on the back of it that gets extremely hot. I took a pick of the section that is sort of scraped up. Also there is a capacitor that looks like it may be blown. Any idea or should I just part this out?

[ReeceyBurger123]

Re: Oh 55LE5500 panel tab

Shorted tabbond driver Ic, not fixable. They probably tried to isolate that tab to get the rest of the screen to work.

[splatee]

Re: Oh 55LE5500 panel tab

Well that's not what I wanted to hear, but I guess that's the chance you take sometimes. I guess I can always part it out.

Thank you

[splatee]

Re: Oh 55LE5500 panel tab

Here is another pic of the symptom. I wonder if there is also a way to go over those scraped traces like with a copper solder pen perhaps?

[budm]

Re: Oh 55LE5500 panel tab

It looks like that section got damaged by liquid (white powder residue and corroded coppers), is the board on the bottom edge of the panel?

[splatee]

Re: Oh 55LE5500 panel tab

Yes it is on the bottom right hand side. The left half of the panel is perfect. The right half is intermittent. If I put pressure on the middle section of the ribbon tab board I can get 3/4 of the screen to show while the last ribbon tab just shows lines. Also the right half has a slight contrast difference like it's slightly washed out but not very noticeable. I am just wondering if there is anything that may need to be replaced on the left side, possibly a bad capacitor? Probally just wishful thinking on my part.

Thank you

[budm]

Re: Oh 55LE5500 panel tab

That is what thought, people spray the cleaner on the screen so the cleaning liquid drips on to the board and corroded away the coppers and also conductive instead of damping the towel with cleaner and then wipe the screen.
You can use good magnifying glass to see if the traces are eaten away, check the resistance of the the caps to see if any of them show very low resistance, etc.

[splatee]

Re: Oh 55LE5500 panel tab

Ok checked the surface mount capacitor and it has a low value. Checked the ones on the next ribbon tab and those look good. Also looking at the ribbon tab I do not see any corrosion it's just right there on that area in picture of the board. Also looking at the metal fram that covers the ribbon cables I can see the corrosion from whatever it was that was split. So I wonder if the only problem can be that capacitor? I have no clue on what the value of that would be.

[budm]

Re: Oh 55LE5500 panel tab

I would at least remove the suspect cap and measure the resistance again.

[jason123]

Re: Oh 55LE5500 panel tab

Any chance any of you know what LED is used on this set? This is edge-Lit and I see LG has 2 types of Discrete LEDs for their TVs, they have the 6V and 3V both roughtly 7030 package size and land pattern.. Just curious if someone has measured the voltage across these LEDs (or total voltage per strip and number of LEDs per strip?)
Thanks