Güncel sürümün sahibi: oldturkey03

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Durum:

open

Düzenleyen: Albert Vierstein

Metin:

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Düzenleyen: Albert Vierstein

Metin:

Durum:

open

Orijinal gönderinin sahibi: Albert Vierstein

Metin:

== ***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. ==

[image|3261455]

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.

[image|3261457]

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,

[image|3261458]

Not knowing the cause I tried everything except replacing boards due to availability.

== ***Things I've done without any effect***: ==

* ***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)[br]

[image|3261472]

* 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[br]

[image|3261466]

* 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.

== ***3 days for nothing. I almost gave up.*** ==

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.

[image|3261479]

(not the actuel picture, because I forgot to take one)

Wipe this multiple times (one minute) and BAM:

== ***No lines anymore!*** ==

I also cleaned the other one and this fixed the herizontal lines!

[image|3261481]

== ***Conclusion:*** ==

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.[br]

[image|3261470]

Durum:

open