Help Request - RCA 50" FHD LED TV (Model: RLDED5078A) - Page 1
Forum section: electronics / repair

author: EBW
author_rank: Contributor
timestamp: November 06, 2023, 11:34:20 am
content: I acquired a defective 50" RCA TV for free:RCA TV Model: RLDED5078AAUO LCD Model: T500HVN01.0AUO T-Con Model: 50T03-C0AInitial Symtoms:1. Turns on OK (Blue LED)2. No data reaching LCD3. Burnt power management IC (AUO M106-11) found on T-ConCurrent Symtoms (After replacing T-Con board):1. TV working but with an issue.2. Every 6th row(?) on the left side of the LCD cycles on and off at a frequency of about 1 HZ. When "on" the picture is perfect, when "off" each 6th row is black on the left side (horizontal black lines).3. The power management IC on the T-Con is getting excessively hot.To me, this is indicating a partial short (excessive current) after the T-Con. I don't see any physical evidence of a problem on the left LCD circuit board or the left COFs. Therefore, I think this is a candidate for scotch tape on the ribbon cable at the connector leaving the T-Con. Does anyone know of a tutorial (or otherwise) to locate the appropriate pin(s)?

author: tom66
author_rank: Super Contributor
timestamp: November 06, 2023, 12:54:26 pm
content: This is likely due to a defective row driver IC in the panel. Unless the panel is lucky enough to have row drivers on either side of the panel (you can remove the 'bad' side), it probably can't be fixed.

author: EBW
author_rank: Contributor
timestamp: November 06, 2023, 01:07:48 pm
content: Quote from: tom66 on November 06, 2023, 12:54:26 pmHi tom66, thanks for the reply. Have you ever used the scotch tape method to isolate the offending item from the circuit? If yes, why wouldn't it work here?

author: tom66
author_rank: Super Contributor
timestamp: November 07, 2023, 01:51:45 pm
content: Quote from: EBW on November 06, 2023, 01:07:48 pmI have repaired over 100 LCD TVs in my prior years and am familiar with what the trick does.In general it only works with panels that have gate-on-panel row drivers on both ends. This is really only common on older full HD panels and modern 4K panels. Essentially you are turning off the driver that is defective and leaving just the left hand or right hand driver to do all of the work.If you can identify that the panel has gate-on-panel (it will have no gate driver chips attached to either side of the panel) and two sets gate drivers, then it may work but the caution has to be given that the other gate driver on the opposite side will now be taking more load current and is more likely to fail in future. However it could give a few more years life to the TV. I would never do it to a TV I intended to sell on, but it's fine for personal/friends-and-family use.On very old TVs you can find the gate driver chips attached to the edge of the panel and physically remove the offending one.The problem will be finding the pinout - if it is not documented you will be left guessing - sadly I do not know what it would be for your panel.

author: EBW
author_rank: Contributor
timestamp: November 07, 2023, 02:48:23 pm
content: Quote from: tom66 on November 07, 2023, 01:51:45 pmHi tom66, thanks for the reply. As a test, I left the appropriate ribbon cable inserted but not clamped then applied finger pressure at various points along the contacts. Applying the pressure on one of the ends elliminated the lines with a perfect picture. Yay, I found the solution and some more operational time is always good. Thanks again!

author: EBW
author_rank: Contributor
timestamp: November 07, 2023, 05:31:56 pm
content: Hi all, a small piece of scotch tape and it now works like new!