Question TCL Backlight but no image. Replaced video board. Worth replacing power too?

[TVNewbie23]

Model: TCL Roku 49s405

Powers on, backlight present, no image. Unknown if it produces sound but nothing from the 3 main HDMI inputs.

Opened it up. Power board, video board, and wifi board clearly visible, nothing noticeably damaged. I replaced the video board since the thing powers up well, but it didn't resolve the issue. I don't see a TCON board. Worth changing out power board as well?

Any other thoughts on repair?

 

[helpstar]

should be the T-CON board
https://www.shopjimmy.com/tcl-55s405-service-no-55s405tmaa-complete-tv-repair-parts-kit.htm

View: https/www.youtube.com/watch?v=p_vj_KLXQ0I

 

[TVNewbie23]

this one doesn't have a tcon board

 

[helpstar]

Then it´s integrated in the motherboard. Where do the ribbon cables go to?

Please take some pictures of the hardware, upload to imgur.com or similar and post the links

 

[TVNewbie23]

Thanks for taking a look. I've now replaced the ribbon and the main board. Still same backlit but no image. Here's the insides:

https://imgur.com/MWO4Uww

View: https/imgur.com/MWO4Uww

https://imgur.com/VNmI8VF

View: https/imgur.com/VNmI8VF

https://imgur.com/GJAJJwm

View: https/imgur.com/GJAJJwm

https://imgur.com/K24R37l

View: https/imgur.com/K24R37l


So, integrated TCon? What else should I replace?

 

[helpstar]

check the board which is connected to the motherboard with the black and wide ribbon cable in the left lower corner in this picture:

https://imgur.com/VNmI8VF

View: https/imgur.com/VNmI8VF


There should be the TCON board, behind a metallic shield.


Could be like this, which means that the TV is most likely not repairable by yourself, because the panel stripes are soldered or glued directly to the board
https://movaz-trade.com/tcon-board-model-18y_55hu11up26axslv0-1-tcl-model-55s421/

 

[TVNewbie23]

Yep:

https://imgur.com/kghsFtf

View: https/imgur.com/kghsFtf

View: https/imgur.com/kghsFtf

(image is upside down relative to the others I posted)

So that's a TCON? And yes, there are ribbons that extend upward in the image (bottom of the TV) and curl around forward towards the actual LCD panel. There are 2 such boards that extend across the entire bottom of the unit, so I'm somewhat surprised I don't at least see picture on half the set. Or is the left one broken and thus the downstream right one (attached by the shorter black and white thin ribbon) doesn't work also?

So is that it? Game over? Trash the whole thing?

 

[helpstar]

So that's a TCON?

The T-Con board in this TV is integrated on the bottom panel driver board.

There are 2 such boards that extend across the entire bottom of the unit, so I'm somewhat surprised I don't at least see picture on half the set. Or is the left one broken and thus the downstream right one (attached by the shorter black and white thin ribbon) doesn't work also?

The T-con controller is a circuit on one of these boards, these boards are divided into two parts, but connected directly with a ribbon cable. Maybe because of lack of space. The controller chip can sit left or right, but controls both sides of the panel.

Your error usually is a T-Con failure.

]View: https/youtu.be/hT4rUkN7Xn0?t=328[/QUOTE]

So is that it? Game over? Trash the whole thing?

It´s always difficult to say yes or no if I don´t have the hardware in front of me. Sorry

You still can replace the power board and if you are lucky, the fault was sitting there.

 

[carlosj_2009]

Model: TCL Roku 49s405

Powers on, backlight present, no image. Unknown if it produces sound but nothing from the 3 main HDMI inputs.

Opened it up. Power board, video board, and wifi board clearly visible, nothing noticeably damaged. I replaced the video board since the thing powers up well, but it didn't resolve the issue. I don't see a TCON board. Worth changing out power board as well?

Any other thoughts on repair?

Hey there! I have a TCL tv which shows the same issues. I ordered the boards and changed them. But the tv still only shows backlight and no image. sound and remote works (you can tell by the change in the intensity of the backlight).

Just wanted to know if you had luck with yours? is it repairable? or no luck?