Sharp LC-C6077UN With Uniform Black Horizontal Lines

[aaronwt6]

Wanted to get a few opinions on this before I proceed with a board replacement. This is my sister's TV that I acquired from a neighbor of mine a few years ago. At the time, it needed a new main board. I replaced that and gave the TV to my sister and her husband. It worked perfect for about a year then started occasionally exhibiting the horizontal black lines that I have shown. Typically, either turning it off for a minute would clear up the problem. It would go weeks to even months at a time in-between with no symptoms but lately, it's constant. I went to her house this weekend (4 hours away) for a visit and brought the original main board for it that I had kept for testing purposes as it simply had no working HDMI ports. It shows the same symptom so it's not a main board problem.

So, here's my question. This thing has a two board T-con setup. I'm assuming that the bottom one connecting to the panel is the 120Hz motion board and the top one is the actual T-con. Any opinion as to which one would cause these lines? I've reseated and cleaned all the ribbons as well as tried turning off the 120Hz feature and neither had any affect at all. My istinct is that it's the larger board on top but figured I'd check with the gurus first. Oh, and if it makes any difference, the boards are oriented at the bottom of the TV (smaller board connects to the panel).

Thanks as always for the advice!

[CapLeaker]

Re: Sharp LC-C6077UN With Uniform Black Horizontal Lines

try heating up those 2 boards with a hair dryer and see if something changes on the screen.

[aaronwt6]

Re: Sharp LC-C6077UN With Uniform Black Horizontal Lines

I did that while I was there and also tried cooling them. Neither had any effect at all. The lines are in a fixed position and do not seem to vary at all. I think I'm going to try the top board first and see what happens. It's only around $20.

Again, does anyone know how this split setup works? Is the bottom one just the 120Hz board are do they both have an effect on the picture output? If turning off the 120Hz feature is basically bypassing the bottom board, then the issue has got to be in the upper one. People have both boards listed as t-cons but obviously they aren't both serving the same purpose.

Thanks for the advice regardless CapLeaker.

[CapLeaker]

Re: Sharp LC-C6077UN With Uniform Black Horizontal Lines

try heating up the main board and also reseat all hose ribbon cables.

[aaronwt6]

Re: Sharp LC-C6077UN With Uniform Black Horizontal Lines

I'm back at home now without access to the TV but I did bring up the original main board with me that I changed out over 2 1/2 years ago due to the HDMI ports not working. It showed the same symptom so I've ruled that out as a cause. I also removed, cleaned, and reseated all connectors while I was there with no change.

[aaronwt6]

Re: Sharp LC-C6077UN With Uniform Black Horizontal Lines

I just thought I would update everyone on this. I ordered both boards and had them sent to my sister's house. My brother in law started with the top one and the problem still existed. Changed out the lower one and we had a winner. Bad part number RUNTK4221TPZA. Again, I'm unsure on this TV if this is simply part of the 120Hz motion clearing option but the lines were present whether or not it was activated in the system menu. The upper board appears more like a typical T-con to me but maybe that lower one does some of the picture processing as well even at the standard 60Hz. If anyone has some insight on that I'd certainly like to hear some feedback.

Regardless, they are glad to have the TV back working and once again I've learned something new.

[aaronwt6]

Re: Sharp LC-C6077UN With Uniform Black Horizontal Lines

I looked at the service manual for this TV and it lists that board as the FPGA unit (Field Programmable Gate Array).

[budm]

Re: Sharp LC-C6077UN With Uniform Black Horizontal Lines

The board between the main board and the T-CON board should be the FRC (Frame Rate Conversion) board.

FPGA: http://www.xilinx.com/training/fpga/...gate-array.htm

[aaronwt6]

Re: Sharp LC-C6077UN With Uniform Black Horizontal Lines

The cable goes directly from the main board to the t-con that I have pictured. I guess the frame rate processing is either taking place on the main boar or the t-con itself. I cannot recall seeing another TV with a setup like this one has and I've certainly gone through plenty.

Thanks for the link budm

Here's the actual chip that's on the board. Not sure if it's what was causing the fault or not but certainly possible.

https://www.altera.com/products/fpga.../overview.html