Sony XBR-49X700D: Vertical Lines

[lothian]

Sony XBR-49X700D
Manuf: 2017

Yet another post complaining about vertical lines in an LED...

I have a Sony XBR-49X700D that decided one day to display a black screen and the dreaded "Sony Six Red Blinks". I buried my face in my hands, fully aware that this particular error code typically means either of two things: a failed T-CON board, or (more likely) one or more dead backlight LEDs.

I did the easiest thing first: I swapped the T-CON board... with no change in status. I heaved a plaintive sigh, and began the onerous chore of complete disassembly of the TV to get to the LED backlight. Sure enough, one of the LEDs in one of the boards tested dead. I replaced the bad LED strip with new. The backlight array works perfectly with no red blink code. However...

Now the display has vertical lines on both sides and a large swath of grey cuts along the middle (see image). Vertical lines typically are caused by a bad T-CON board followed by a poor connection of the ribbon cable. I swapped the former and re-seated the latter--no change.

Surely there's some simple thing I've overlooked. I am stumped.
What causes vertical lines? What else should I check?

[budm]

Re: Sony XBR-49X700D: Vertical Lines

Tab bonding could have been damaged when you disassemble the panel.

[lothian]

Re: Sony XBR-49X700D: Vertical Lines

I have no idea what tab bonding is. But I'm guessing it refers to the hard connection between the many flex ribbon connectors affixed to the panel display. And I'm further guessing a problem with tab bonding is game over.

In any case, I've jiggled, pressed and yanked on each ribbon at the panel with no apparent effect on the display. So, other than palpation, how do test these things?

[budwich]

Re: Sony XBR-49X700D: Vertical Lines

post some pictures of the back of the set so the forum can see how things are connected up. Right now, I would say you have a poor connection between the tcon and main board. From there, start checking "labelled voltages" (ie. pins / connections that are labelled at the connectors). Post those results (ie. pin #, label, measured voltage).

[lothian]

Re: Sony XBR-49X700D: Vertical Lines

The panel must be removed to access the backlight, and I was especially careful when I removed that thing. Nevertheless, the vertical lines appeared after I put the thing back together.









I have two TCON boards; I've swapped in both with no change.




At this point, I suspect I damaged three of the panel ribbon connectors--somehow. I cannot believe the panel ribbon connectors are so sensitive you can't breath on them without breaking the bond. I've pressed/pulled on the panel ribbons nearest the vertical lines with the display powered on--there's no change in the vertical lines.

I remain stumped.

Oh look... BestBuy has a couple 55" LG 4K TV's for under $500.
Methinks it might be time to monetize the innards of this TV on eBay...

[nomoresonys]

Re: Sony XBR-49X700D: Vertical Lines

Black Friday cometh soon.

[lothian]

Re: Sony XBR-49X700D: Vertical Lines

Perzactly.
I'd like to fix this two year old TV. I'd like to confirm this TV is irreparable (i.e., damaged panel). I'd prefer to not spend a few hundred buck on a new TV.

But my time has value.


On another subject...
I read in other forums that the Sony TV "six flash code" is basically a harbinger of death for the affected TV.
In my case with this XBR-49X700D, it began one day with a dark panel and a "six flash code". My problem morphed from one problem (which I seemingly fixed) to another (vertical lines).

Oh well.

[nomoresonys]

Re: Sony XBR-49X700D: Vertical Lines

Taping buffer board to panel when switching out led strips, at 3:46: https://www.youtube.com/watch?v=y5d_JkOEBSg

[nomoresonys]

Re: Sony XBR-49X700D: Vertical Lines

Could try cleaning your tcon ribbon cable ends, some use a pencil eraser.

[lothian]

Re: Sony XBR-49X700D: Vertical Lines

Did that (sans pencil eraser). Both ends. I disconnected the two short ribbon cables btwn the TCON and panel buffer boards and "cleaned" the ends with isopropyl alcohol and a Q-tip. No change to the vertical lines.

[nomoresonys]

Re: Sony XBR-49X700D: Vertical Lines

Does lvds cable from tcon to mainboard have a good connection and clean? maybe unhook and reconnect it.

[budwich]

Re: Sony XBR-49X700D: Vertical Lines

how is the bottom (top?) edge board designed and connected to the panel? Is there multiple boards on each side or just one per "half"? Picture?

[lothian]

Re: Sony XBR-49X700D: Vertical Lines

Two boards, left and right, each with six ribbon cables affixed (i.e., "bonded") to the panel.

[budwich]

Re: Sony XBR-49X700D: Vertical Lines

thanks... the set also has tabs on the side, right?

It is strange that the issue shows up "symmetrically" on both sides.... that seems to indicate a problem further up than the panel.... maybe.

what happens when you disconnect one cable from the tcon to panel. That side should go "smooth white".

[dick_barton]

Re: Sony XBR-49X700D: Vertical Lines

When you removed the tcon and also when you replaced it did you lift the tabs on the cable connectors to release the ribbon cables or did you pull out/push in?
If you did not lift the tabs to release the ribbon cables them then the cable ends with the gold contacts could be damaged.

[lothian]

Re: Sony XBR-49X700D: Vertical Lines

You are exactly correct: I damaged the ribbon connectors at the panel when I flipped the panel over. D'oh!

Truly a bummer. I had successfully repaired the source of the "5 blink" code on this TV--a bad LED strip--and in doing so, managed to jostle the panel just enough to break the connection somehow.

Oh well... live and learn.