Bad Panel in Sony Bravia X850G

[guidodroid]

Hello all,
I'm trying to understand what is the issue with my 26 months old Sony Bravia KD-65XG8505 (XBR65X850G).
It is just few months out of warranty, so Sony doesn't want to do anything, and the local replacement shop also tells me that it's not worth repairing (alhtough this model costed almost 1000 euros just 2 years ago...).

Few nights ago the TV started showing some horizontal lines and distorted colors/geometries in the bottom part of the screen (see attached photos).
The issue is not as bad as others that I've seen around, but is indeed noticeable and quite annoying. Nothing special happened (like lightnings, high temperatures or shocks), so this is an internal fail.





I already opened the back to search for obvious fried components (found none) and replaced the T-CON, but the issue persisted. However, when doing so, I tried to disconnect only one of the ribbon cable bringing the signal from the T-CON to the panel and noticed that, with only the right one connected, the horizontal lines disappeared from the screen. This was not the case with the left one connected, which showed the lines on all panel (even though only half of the screen had an image).

That's why I'm kind of convinced the issue lies somewhere within the connection of the panel, only for one of the side coming from the T-CON. Could you give me some advices on how to progress further in finding the culprit? I'm thinking one of the connection of the panel is faulty, but is there any way to find which one and to fix it? I have the possibility of buying and replacing the motherboard or the power supply card, but I'm not sure it will fix the issue.

Thanks

[neilc6]

Re: Bad Panel in Sony Bravia X850G

https://techhometravel.com/repair-of...lines-on-a-tv/

[Diah]

Re: Bad Panel in Sony Bravia X850G

since there are no external act or move to the set... its lack / noise at one channel LVDS signal... take out LVDS clean them and inspect it carefully after that apply hard reset. again hard reset.

[nomoresonys]

Re: Bad Panel in Sony Bravia X850G

I second the tape-cutoff method in post #2, easy enough to try.

[guidodroid]

Re: Bad Panel in Sony Bravia X850G

I second the tape-cutoff method in post #2, easy enough to try.

I tried the tape-cutoff method. Unfortunately even when blocking a single channel of the ribbon cable l I don't get any signal on the TV. Looking at those videos on YouTube, whenever they disconnect one of the ribbon cables, they have a full image on half of the screen. In my case, instead, I only have a white image on half of the screen. That's why I have the impression that in this new model probably the difference between the Left and Right channel is not completely symmetric... But that was just a hypothesis.

[guidodroid]

Re: Bad Panel in Sony Bravia X850G

since there are no external act or move to the set... its lack / noise at one channel LVDS signal... take out LVDS clean them and inspect it carefully after that apply hard reset. again hard reset.

I may not be super familiar with the terminology: you mean the cables brining the signal from the motherboard to the T-con right? I tried cleaning them up on one side but that didn't bring much unfortunately.

[Diah]

Re: Bad Panel in Sony Bravia X850G

why just clean on one side only !!!!!
show us photo on the whole back of the tv showing all boards .. also one photo very close high resolution of the LVDS socket on the mother boards side

use GO Advance and upload the photos... don't use external server for upload please

[guidodroid]

Re: Bad Panel in Sony Bravia X850G

why just clean on one side only !!!!!
show us photo on the whole back of the tv showing all boards .. also one photo very close high resolution of the LVDS socket on the mother boards side

use GO Advance and upload the photos... don't use external server for upload please

Sure, I'll open the TV tomorrow and take new pictures. In the meantime these are some close-up shot that I took the other day when I was trying to figure out the issue.

[Diah]

Re: Bad Panel in Sony Bravia X850G

Sure, I'll open the TV tomorrow and take new pictures. In the meantime these are some close-up shot that I took the other day when I was trying to figure out the issue.

thanks for the photos. i think now i know why you dont plug out the LVDS from Main boards side LOL.... if you dont know just ask..
cleaning them and after that hard reset will give you good result.

if this dont help there are working around to mask on LVDS 51Pin.. let see after you open it again.

and tell which part you are talking on (( fried components (found none) ))

[guidodroid]

Re: Bad Panel in Sony Bravia X850G

i think now i know why you dont plug out the LVDS from Main boards side LOL.... if you dont know just ask..

What do you mean?

cleaning them and after that hard reset will give you good result.

if this dont help there are working around to mask on LVDS 51Pin.. let see after you open it again.

But just to be clear you're still thinking that the problem is when the signal goes from the motherboard to the T-CON and not afterwards from T-CON to the panel...right? If that would be the case wouldn't I see the issue anyway regardless of the ribbon cable that I disconnect from the T-CON? Sorry if this is a stupid question, as you saw that's my first time repairing a TV

[Diah]

Re: Bad Panel in Sony Bravia X850G

But just to be clear you're still thinking that the problem is when the signal goes from the motherboard to the T-CON and not afterwards from T-CON to the panel...right? If that would be the case wouldn't I see the issue anyway regardless of the ribbon cable that I disconnect from the T-CON? Sorry if this is a stupid question, as you saw that's my first time repairing a TV

LVDS signal are double or more channel. depend on the mother boards design. if there are lack or noise at one of them... they will remain give the bad result at the specific channel.
its huge mistake if we going to judge the panel COFs or buffer boards with out we follow it from the source.. the source are PCB ---- Main boards ---- LVDS ---- T-CON---ribbon --- buffer boards --- COFs.

we saw many there was BGA issue on MB cause same issue or little worse... either LVDS we saw it caused. dropping voltage on MB caused it too.

so i am one who are against cut method.. before we are sure all parts i talked on are fine. you can start with reduce load on currents to see if there any effect.. like turn off WIFI module... Bluetooth ,, reduce BL under 30%. mute the sound , or reduce contrast / gamma ..etc or all these do it one time together to see if the noise became a little or disappear.

if all didn't bring any change do the clean i asked you before and must important the hard reset from service menu.

[dskall]

Re: Bad Panel in Sony Bravia X850G

I wouldn't bother with a mainboard or power supply. You probably have a timing problem at one of the side cofs. Cutting ckv trace my fix it. Lots of youtube videos.

[nomoresonys]

Re: Bad Panel in Sony Bravia X850G

yep, do as described in post #11, reduce the load and turn down the backlights, see if there's an improvement in the display.

[guidodroid]

Re: Bad Panel in Sony Bravia X850G

So I tried to reduce the load but that didn't fix the issue.

Instead I tried to apply again the tape method and had some good results!
By trying to block only the clock lines I was able to get rid of the horizontal lines and the flickering

Unfortunately the resulting picture is not perfect...there are some noticeable black bands across all the screen (but seems more on the left side, not sure why). I experimented a little bit with the tape width but unfortunately was not able to get a result better than this. By blocking only the first few lines of clock the stripes density increased, while by blocking too many lines at some point I only got a white screen.
The sweet spot seems to be somewhere in between but I tried so many different combinations of tape width, trying to block only what seem to be the clock lines but those stripes are still there.

Do you think it's possible to get completely rid of the stripes or it's quite hard to get a "perfect" result as I'm basically ignoring one of the two clock signals from the T-CON?

[guidodroid]

Re: Bad Panel in Sony Bravia X850G

I may have good news. After some trial and error I get a picture where I cannot find (I think) any issues. I don't want to jinx it but I may have fixed it
In the end I blocked some of the clock lines (excluding the first ones) and I don't see anymore horizontal lines.

[nomoresonys]

Re: Bad Panel in Sony Bravia X850G

Nice job, credit to you for not giving up on the good ole tape cutoff method.

[guidodroid]

Re: Bad Panel in Sony Bravia X850G

So after a few days actually I can say that the picture is not as before...there is a very evident saturation gradient as the colors on the left side of the TV are washed out.
I tried to play along with the tape but I can only get in two different regimes: either uniform color but with some horizontal stripes over the whole panel and some flicker in the left part, or no stripes but washed out colors in the left.
The latter happens when I try to cover all the clock lines of the left ribbon cable, the former when I cover only some.
Honestly I don't think I can expect more from this repair: the picture will always have issues. So for now I decided to go for the second version with washed out colors.

Don't know if someone had a similar experience

[Unspun01]

Re: Bad Panel in Sony Bravia X850G

So after a few days actually I can say that the picture is not as before...there is a very evident saturation gradient as the colors on the left side of the TV are washed out.
I tried to play along with the tape but I can only get in two different regimes: either uniform color but with some horizontal stripes over the whole panel and some flicker in the left part, or no stripes but washed out colors in the left.
The latter happens when I try to cover all the clock lines of the left ribbon cable, the former when I cover only some.
Honestly I don't think I can expect more from this repair: the picture will always have issues. So for now I decided to go for the second version with washed out colors.

Don't know if someone had a similar experience

Do not give up. I have repaired both LG (more common), and Samsung 4K TV with this tape method. On the samsung, I had the hardest time. Lots of trial and error. While covering all the clock lines may have stopped your jittery or double image, one or more of those lines may need to be "uncovered" to restore correct picture.

In my case, TV would be backlights with black screen only, no image. I taped over like 10-15 lines not knowing what they did, or how. Once the picture came back on, I knew I was in luck. But there was a "pulsing" to my image where it was brighter, then dimmer, then brighter, then dimmer, etc. I tried many different widths of tape, and in many variations of pins, until magically one width of tape over a certain number of pins worked!

My advice is to cover as many of those gate/clock lines until your image stops jumping. Then make detailed notes on paper with images of various combinations you try, and their results. You may find correct solution through trial and error as I did.

I know this is super unprofessional process, but it worked. Trust your documentation.