Can you dignose from the photo ? . Toshiba 65S2650EV

[Ancient1]

Hi

The issue I am trying to locate is seen in the attached Images. I.E What should be repaired.

The TV got a bump / fell . Works fine - almost
General Design is Standard LED TV : PSU , Main, T-con with 2 Flex cables - to 2 Panel Boards.

The only issue is with the image quality.
The TV Menu's Image Settings are medium/standard. nothing extreme.

The General look is Solarized ? : White shadows , Darkish , and colors are too strong
Most important in my opinion are the Grayscaled areas.

I tried cellotaping tracks on the Flexes. No joy.

I do suspect the Gamma system. I traced them to To the T-con Big Chip - marked in an image.
T-con was inspected with magnifying glass - looks OK.

Any suggestions ?
It's a 65" TV

[petehall347]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

left ribbon cable not in correctly

[dskall]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

Each gamma voltage should be in asending or desending order depending where you start.

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

Gamma Voltage results photo

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

left ribbon cable not in correctly

Thx
Did the cellotape trick so many times .. the Flex is fine, clean and the connectors too.. basic

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

Each gamma voltage should be in asending or desending order depending where you start.

Thx
Please check the new photo of Gamma measurements

I need someone with VGH VGL etc knowledge :/

[dskall]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

I really don't think you have gamma problem. What do you get when disconnecting each side?

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

I really don't think you have gamma problem. What do you get when disconnecting each side?

Thx
While the Gamma measurements look mostly fine : I assume the line starts on one board and comes back on the other : all are paired with same V basically , BUT one : the 0.447 and the fluctuating V .
This fluctuating test point doesn't seem to be connected, but it strengthened the guess that I have Gamma issue ( started with image having grayscale areas)

I am uploading a sequence of images for each Flex since there's this "fading" phenomena vs "Popping right up" as in normal display .
They are named "Left #" and "Right #" , with description in them

Thx !

65"

[dskall]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

Seem to have problem on right side. Have you checked other voltages on t-con?

[Davi.p]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

gate drivers from one side are not receiving a signal, i think VGH or VGL, must open screen bezel to show if present COF or COG, if COG repair not possibile maybe unless you shut off bad side

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

Seem to have problem on right side. Have you checked other voltages on t-con?

Hi

I did not check V as I am not knowledgeable in them ( I might be finding the fault without knowing that I did) , I can't find a pdf explaining this subject but I found on Youtube a new, pretty good, channel .
Here's a link to one clip of the series https://youtu.be/I3dFanaLdTc

I did not check V since I assume(d) they are fine : The LOGO appears OK, and I was/am under the assumption of Gamma issue.
I don't have a oscilloscope for the (twisted ?) Pairs

In short : what should I check and what should I see ?

Thx for the help !

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

gate drivers from one side are not receiving a signal, i think VGH or VGL, must open screen bezel to show if present COF or COG, if COG repair not possibile maybe unless you shut off bad side

Ciao . Grazie per il feedback

I want to make certain I understand you :
1. VGL or VGH lines ( Which Flex / Side of the visible Panel ) are damaged.
2. I should find which exactly by investigating the COFs ( COF = COG ?) on the Panel ( Top or Side COF ? )
3. Assuming I find an anomaly, I should repair the line/s or, If not possible , MASK ( cellotape) the track on the Flex from the T-con ?

OK.
Since Dskall and you converge on "other Voltages", I will take VGL VGH measurements : on T-con and further down the line, upload, and let you tell me what you think.
The plan is to measure every test point which is marked by VGH/VGH.
It will take some time, so I would appreciate if you would "follow" this thread.

Thanks !

[Davi.p]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

Watching from the front and with the screen right the fault is in left side so the right in your pictures, cof are those chips external from the screen, in newer lcd they can be within the glass and their name are COG, so if you find COF you can gently scrape testpoints on film and test in both sides (i am talking about vertical sides tabs) to find which testpoint is vgl and vgh in good side then in bad side you can test if one of those are interrupted so you can reconstruct it by wire..

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

Watching from the front and with the screen right the fault is in left side so the right in your pictures,

This is a bit confusing : My TV is upside down and when I talk about Left/Right I am referring to how it is now, not when placed normally - but you did ?

What I understand from the rest is : check the "good side" COF ( Chip On Flex) and compare to the "Bad Side" : they should be mirrored. You ( me) may see correct VGL ( for example ) on the boards while the line is damaged in the Panel ??
I will. I've seen , mostly ppl in India, do that. For now, I decided to measure ALL Test Points on the Panel Boards. Takes some preparation

With regard to the boards : is one the IN board and the other Out board ? since I have Gamma test point clusters in both boards

[Davi.p]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

Watching from the front and with the screen RIGHT the fault is in left side.
For the restdo one thing a time, remove bezel from the screen and we see if there are side tabs..

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

Watching from the front and with the screen RIGHT the fault is in left side.
For the restdo one thing a time, remove bezel from the screen and we see if there are side tabs..

Ok, so by "RIGHT" you mean : not up-side down. The fault is on the side with grayscaled squares in the image

There are Side Tabs , I repaired a couple of LEDs , than replaced all. long story

I wanted to be sure : I check the Side Tabs COF for V , not Continuity or such, right ?
Also, are the Left and Right Tabs a mirror image ? does the line come from , say, (Panel Board) Left side , through the Row , to the Right and back to the other Panel Board ?

Thanks !!

[Davi.p]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

Ok, so by "RIGHT" you mean : not up-side down

yes.
If you have VGH, VGL test points on tcon it's better to check continuity, do it first to the good side so you can find the correct testpoint, there are on the net collections of testpoints, search if you want the code impressed to the tab near the word datasheet. The VGH lines are not running trough the row but are split in 2 in the tcon, 1 for left, 1 for right. Left / right tabs are mirrored.

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

yes.
If you have VGH, VGL test points on tcon it's better to check continuity, do it first to the good side so you can find the correct testpoint, you mean Continuity between the T-con Point and the Side COF , yes ? makes sense since a break in this line is what we look for

there are on the net collections of testpoints, search if you want the code impressed to the tab near the word datasheet. You mean Datasheet of the Side COF . correct ?

The VGH lines are not running trough the row but are split in 2 in the tcon, 1 for left, 1 for right. Left / right tabs are mirrored.

I see VGL and VGH on the T-con : You can look at the T-con image I uploaded with First post ( Hi-Rez, click to open and click again to be able to click (+) for 100% view - better in a big screen): they are on one side only ( what I could find) - on the right of the right side connector in the image ( above 21 in the date)


OK, I understand better what to do ! Thx !

[Davi.p]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

VGH/VGL testpoints are on one side but signals are split in two, if you use continuity test of multimeter you find the signals on both connectors..

[Ancient1]

Re: Can you dignose from the photo ? . Toshiba 65S2650EV

Ok

Right side board - Right as in the full photo - All Test Points Measured :
Due to its Length : I have 6 images , consecutive from Left (mid TV) to Right , i.e as you would see the board

* few points have cycling mV : 0 to ~350 usually