What causes thin black horizontal lines on tv panel

Question

TCL Television

Televisions made by the Chinese multinational electronics company, TCL.

crwdns2934591:020crwdne2934591:0 crwdns2934593:0crwdne2934593:0

Ric @noric

crwdns2934065:0crwdne2934065:0: 13

2

crwdns2931729:0crwdne2931729:0: Kul 3, 2022

crwdns2933897:0crwdne2933897:0

What causes thin black horizontal lines on tv panel

Hello,

I’ve been having this issue with my TCL 55” C70 tv for a few days. There are very thin black horizontal lines coming from the top right part of the panel. They are not static, but intermittent. They appear and disappear at regular intervals and follow a regular pattern.

While the lines are solid black on the right, they tend to become lighter (greyish) to the center of the display. They are not even visible on the left.

Also, sometimes there are only a few lines at the top right, sometimes there are more lines coming down towards the bottom, as you can see in this video: https://www.dropbox.com/s/0bu8alax9nburx...

In the video it appears like a darkening (backlight) problem, but it’s actually specific lines of black pixels. You can see this from a close-up photo (zoom at 100%), black lines on an image that should be consistent blue: https://www.dropbox.com/s/we3hwj8q3x68a4...

Any advice about what’s causing this problem?

Thank you everyone

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2853045:0crwdne2853045:0 crwdns2853046:0crwdne2853046:0

crwdns2889612:0crwdne2889612:0 1

crwdns2947414:01crwdne2947414:0

@jayeff Thanks for your answer.

Did you happen to watch the video? In my opinion such thin black lines coming from only the right side of the lcd appear like a signalling problem. Don't you think it could be the t-con board?

I've taken the tv apart and there isn't actually a t-con board, but two separate boards for the left and for the right part of the lcd. Could it be one of them is faulty? Here is a picture of them: https://ae01.alicdn.com/kf/Ha94f19f7aca7...

crwdns2934271:0Kul 5, 2022crwdnd2934271:0 Ric crwdne2934271:0

crwdns2934285:0crwdne2934285:0

crwdns2933313:01crwdne2933313:0

@jayeff Thanks for your answer.

Did you happen to watch the video? In my opinion such thin black lines coming from only the right side of the lcd appear like a signalling problem. Don't you think it could be the t-con board?

I've taken the tv apart and there isn't actually a t-con board, but two separate boards for the left and for the right part of the lcd. Could it be one of them is faulty? Here is a picture of them: https://ae01.alicdn.com/kf/Ha94f19f7aca7... — Ric

score 3 · Answer 1 · 2022-03-04T01:32:24-07:00

crwdns2934057:0crwdne2934057:0

jayeff @jayeff

crwdns2934065:0crwdne2934065:0: 508.5crwdns2936485:0crwdne2936485:0

11

393

1.5crwdns2936485:0crwdne2936485:0

crwdns2931729:0crwdne2931729:0: Kul 4, 2022

crwdns2933897:0crwdne2933897:0

Hi @noric ,

Horizontal lines in a TV are a driver problem in the LCD panel assembly and cannot be repaired. The LCD panel will have to be replaced.

Sourcing new replacement TV LCD panels is not easy and if you do manage to find one then it is almost half the cost of a new TV.

If you decide to get a new TV, an option to consider is to advertise the old TV as faulty screen, good for parts to recoup some of the cost towards a new TV. Working TV boards are always in demand

crwdns2934105:0crwdne2934105:0

crwdns2853045:0crwdne2853045:0 crwdns2853046:0crwdne2853046:0

crwdns2889612:0crwdne2889612:0 3

crwdns2947414:01crwdne2947414:0:

Hi @noric

tcon boards (or their equivalent circuitry if on a mainboard) connect via boards either at the top or bottom of the screen and then via fragile cable connections to the vertical pixel columns in a screen and the internal connections to the horizontal pixel rows. i.e. on a 1920 x 1080 display there are 1080 vertical columns of pixels and 1920 horizontal rows of pixels and the image you posted show that the lines are horizontal.

Since the lines are black this means that no power is being supplied to the selected pixel rows as no pixels are being turned on. It would be different if it were red, blue or green lines as this means that one colour is stuck on.

I've never heard of horizontal lines being fixed except by a screen replacement.

Just wondering how you're going to reconnect the boards to the screen. Every connection from the board to the screen has to line up perfectly and stay connected electrically - good luck with that

crwdns2934271:0Kul 5, 2022crwdnd2934271:0 jayeff crwdne2934271:0

crwdns2934285:0crwdne2934285:0

TCL Television

What causes thin black horizontal lines on tv panel

crwdns2933313:01crwdne2933313:0

crwdns2934229:0crwdne2934229:0