Can you dignose from the photo ? . Toshiba 65S2650EV

[Ancient1]

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

"Left" Panel Board Test Points measured

Left side board - Left as in the full photo - All Test Points Measured :
Due to its Length : I have 5 images , consecutive from Left to Right (mid TV) , i.e as you would see the board in the full view image

Next : visual check of the boards and flex, than checking the Side TABs

[Davi.p]

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

Originally Posted by Davi.p View Post
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 ? ---- Yes

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 ? --- Yes

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 dont have noticed your strange quoting, i insert answers... but why you are showing me distribution boards voltage testing? This is totally out of the road.. those are not the tcon

[Ancient1]

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

I uploaded the Panel Boards , distribution boards , simply for reference or future use.

I understand that we were talking about the Side Tab's COFs. I will do that next

[Ancient1]

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

Hi

Opened Bezel

This is first time I am doing this COF probing. Excuse me for being confused a bit.

I have 6 COFs on each side
I managed to take a good photo of a Bad Side Tab COF ( first one, bottom) :
Novatek , NT61323H-C52C5A

Couldn't find Datasheet

How to do the job exactly ? :

1. You said To check continuity between T-con VGH and VGL to the COF. It seems impossible since they are on different sides. Any trick ?
   
2. Seems easier to look for VGH/VGL Voltage on the COF ? or is continuity the way to do it ?
   
3. Am I looking for VGH or VGL ONLY ? or AND dis-similarity between the sides ??
   
4. Are ALL the COFs points arranged the same ? i.e All on same side are the same , and a Mirror image of the other side ? If I find VGH in certain point - they all will have it in same point ?
   
5. Do I have to probe each point ?! until I find the expected Voltage. And the Bad side will be a mirror image and missing the V in the corresponding point ?
   
6. If 2nd COF and its Mirror show missing VGH , would ALL the rest show missing VGH ? i.e I need to deal with just 2 - one on each side, and if I wire back this will solve the cut line ?

Please advise
Thanks a lot

[Davi.p]

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

1. both vgl , vgh arrives to both sides cof so you must check which testpoint holds those signals and if same TP on both sides holds both signals
2. you can also check for voltage, if vgh/vgl missing instead of zero you can find a different voltage
3. for now yes 4. yes 5. yes 6. no, on each side each cof is cascade to each other, so if problem is on entire screen, the interruption is before the first cof from the tcon side, left / right cofs are paralleled, so if the break is only to the left side maybe there is no break to right side so right cof works normally

[Ancient1]

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

OK

So I test/compare the first couple , since the full half is faulty
I test Voltage ( Black to chassy) .

I know ( from distribution board measurements) that VGH = ~26.4V and VGL = ~7.9V.

Last Q :
which side of the COF is the metal ? image side ( front) or the other, the Printed side ?

Thank you very much.
Crossed Fingers

[Davi.p]

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

VGL is negative. The testpoints are painted so you must scratch carefully green paint, use very sharp blade, the testpoints that will result nude must be repainted cause them can easily build oxidation, them are not copper

[Ancient1]

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

My question was what side to scratch. I hope it is the external side so I can leave the panel in place , since I don't want to bend the Flex ( too dangerous I think ) .

I have probes with needle ends, so I am thinking about puncturing the testpoints.

I have the Ultra-Violet Lacquer for PCB - You think its a good choice ? If not - what should be used to cover the copper ?

A lot of details.. thx

[Davi.p]

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

My question was what side to scratch.

said in the last post , green paint to scratch

I have probes with needle ends, so I am thinking about puncturing the testpoints.

you will destroy it, you are not reading me maybe...

I have the Ultra-Violet Lacquer for PCB - You think its a good choice ? If not - what should be used to cover the copper ?

use a dry paint, no matter what it is

[Ancient1]

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

I probably won't be able to do it today, so I have more time to "cook" this job

As I said, I have never done such a job , while I do have experience with repairing TVs, I am a hobbiest. I want to have an exact plan of action , as I think this job is THE fix or fail one.
From experience ( I am not young ), I know how important it is to "play" the job in my mind for a perfect performance.
And the fact that English is not our native language : I want to make certain I understand you 100%.

Its not good to mess with a device or component many times . for example : the Flex from T-con where I covered tracks again and again.. It can be damaged. The TV itself is not something I want to move back and forth a lot.

The thought about puncturing the Side Tabs : Since I don't know which side to scratch , and the underside is VERY hard to access, if at all.

I upload Again a photo of one Tab : Its not "green paint" ! I hope this isn't a misunderstanding between us.

I figure I'll measure every TestPoint , since I will be searching for VGL / VGH so I might as well do them all in one session.

About the Paint : I do have Flex from junk Distribution board : I will test a regular wood lacquer. The PCB UV lacquer was not a good idea since it hardens and will stiffen the Tab, which should be... Flex_ible. What about a Clear Cellotape ?

I hope I am not bothering you, it is VERY important for me to repair this TV. It has a story.. I repaired its backlight, sold, returned , happily replaced all backlight since I will sell it for more and make the owner happier with larger sum.. than found I missed this VGL/VGH.. TV must have fell ! (and I stand to lose quite a bit, but I don't care about MY money, I like repairing !)

[Davi.p]

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

I don't know which is the problem, the tab has 2 facess, one is amber, the other is green with a thin protective paint, this must be scratched, ONLY THIS CAN BE. Try to gently bent it. For the replacement, its not important the flexibility, you must apply that with a toothpick only on the scratched spots. And that's all.

[Ancient1]

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

I am about to measure :
Are Voltages present as should without a Video feed or I must input Video/Image ?

I started the TV before moving it to test place/position, and discovered a change : I attach 3 photos : both Flex , Visual Right Flex OFF and Left Flex OFF ( light bar visible).
The main difference to what was is narrower Light Bar and the Horizontal Line.
No idea why that happened but must be moving the TV to earlier test position and back.

[Ancient1]

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

Hi

I'm about to Measure the Tabs : Do I need a Video/Image feed or [No Input] is enough ?


I started the TV just before moving it for testing, to have an actual reference, and discovered a change from last time.
I attached 3 photos of : Both Flex IN, Left Flex OUT , Right Flex OUT. ( the visual L and R)
Main differences are : Smaller light bar ( L flex off) and a Horizontal line in the regular , bot Flex IN, photo
No idea what this means, but for now I am going to test the Side Tabs

THX

[Davi.p]

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

Probably the cof near the line needs a reflow, no good times for your lovely tv.. in that case watch the discussion actually in 1st page about Sharp 70 inches where i do suggestions.
Don't hear people says COF are the same as TAB, COF IS THE CHIP, TAB IS THE FLEX WITH THE CHIP.

[Ancient1]

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

Oy Vei
I'm training at scratching the paint... and measuring continuity to find the pressure tear point.

I think I'll need to take the Panel out , upside down, and expose the points.

[Davi.p]

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

Try to bent them, it's very hard but flipping the panel is more risky, don't bent them all, only 60 degrees, put a shim under it, make with wood or something

[Ancient1]

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

The Panel is on the carpet , points scraped - see attached photos

Very hard to take photos.. must be the shining surfaces

I'll put it back soon ( when the help arrives ) , and taking measurements isn't easy but hopefully I'll manage as I don't see any other way.

Fingers Crossed

[Davi.p]

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

you had to put an hard surface under them, not carpet, you have misshaped it.. let's hope..

[Ancient1]

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

You are right. But I used a head Magnifying Glass with lamp, and I am pretty certain I didn't puncture or ripped tracks.

Under the surface there is a whitish layer and the copper is under it I think.
In my tests , the tracks withstand a force much larger than what I have used.

I tested continuity in one, exposed, white point : within it : the white layer is conductive.

I got actual needle point DMM probes : I made myself from a Female Molex HDD pin : it fits very well on a regular probe. And the needle is soldered on it. Very Useful !

[Davi.p]

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

As i have stated before there's no copper usually, all are made with silver paint, don't scratch more