It is not the panel, it's the 2 FPCs!
TLDR: Oxidized/bad contacts of the two flat flex cables from T-CON board to the LCD panel distribution board.
I had the exact same issue and fixed it.
For me the issue started with static equally spaced horizontal lines every 6 pixels (this may not be the same for you). I didn't care much, because they were not noticable at normal distances. They were not completely black, but darker. So I lived with it.
After 20 months, out of nothing suddenly also colored vertical lines appeared. Mostly red lines, but some few lines of other colors as well. The intensity varied depending on the displayed image, The lines were on both screen halves, left and right. After power on the lines faded in within 10 seconds. Powering off and on again gave the same observation. The lines, initially non-existent, were fading in slowly,
Not knowing the cause I tried everything except replacing boards due to availability.
- Reseating and wiggling cables. I took out the 2 FPCs (which was the culprit not knowing at that time) multiple times and it did not change anything. So I searched on the T-CON board.
- Heat gun on components
- Freeze spray on components
- Because of some 120Hz ripple on the 12V supply for the T-CON board I tried using an external power supply (it draws about 1.4A - 2A current)
- I reflow soldered the BGA components: 2x RAM chips, Sony and WISE-Processor, because I thought mechanical stress of the heatsinks could have broken some BGA contacts
- I even inspected the panel driver chips and panel substrate, despite it's obvious that it could not be the problem as the stripes were not limited to a specific section (column) of the screen.
I gave it a last try and when I tested the screen with only one of the FPCs seated, suddenly the lines were gone (the screen half of the connected FPC of course).
So I rubbed the FPC pads with antistatic clothing and isopropyl alcohol.
(not the actual picture, because I forgot to take one)
Wipe these pads really good! 2 times is not enough! Do it for a minute or so and BAM:
I also cleaned the other one and this fixed the horizontal lines!
Check your FPCs first and clean them properly! Even if one is responsible for only one screen half it could influnce both halves!
Pressing the connector / cable, pushing, pulling, wiggling and reseating (multiple times) the cable did not make the slightest impression beeing the culprit.
I've also read that adding a stripe of scotch tape on the back of the cable (increases thickness) could improve the contact.
Also check the other end (panel distribution board). For that the screen must lay on it's back to prevent the display falling out.
3条评论
I guess its not the Tcon , but the main-board flash ic problem issue. check whether the 5.5 v mosfet is overheating by touching it.
由 tapas.roy 完成的
I have Sony Bravia LED 3D TV KDL 43W950D. Sl no. 8526842.
Few days before i,e. on 15/12/2020 in the morning when I was started my tv it was displayed white screen then blinking red 5 times and so on. I have informed to Sony Service station then service engineer came to me on18/12/2020 and open the back cover and clean the dust then tv was o.k. I have given him Rs.1300.00 as a service charge. Next day morning same problem appeared. Again service engineer come to me and open the back cover and done something again tv was restored. Next day again same problem appeared he came to me and put software for update then tv was restored and he told me it was a problem of Tcon board but Sony does not supply only tcon board so I have to purchase full panel and it will cost more then 17 thousand. Next day morning same problem persist. why he try to replaced my tv parts instead of minor repairing? Let me know what is the actual problems.
由 Samir Kumar Mukherjee 完成的
@samir kumar mukherjee, do you know where can we get a full panel?
由 Sagar 完成的