Sony KDL40S2000 TCON board issue...

[lenny1972]

Hi, I'm a newbie so sorry in advanced for any stupid think I will write on the forum and for my english (I'm from Italy)....
I need somehelp because my 6 years old 40'' Sony Bravia sudddenly went with a black screen and was brought to assistance.
The problem was found in the TCON board fuse that was replaced.
This solved the problem of the black screen because the TV now works well but after 20/30 minutes of good images (and sound) it suddenly starts to show vertical coloured lines on a black screen..the sound remains good..
Probably is some component that overheat and cause this problem..
Trying to identify the component using an hair-dryer (set on cold) i found that some TCON components its the responsible..In fact after few seconds of air dryer over the TCON, the problem solved (till it goes overheat again..)
I'm wondering if someone of the expert can tell me which can be the component to check for replace and which is the way to measure the component functionality (I've got a multitester only..).
I can try to cold a specific component at a time in order to identify it (trying to reduce the air flow coming out from the hair-drayer..).
A doubt comes into my mind when I see no conductive pads between the TCON board and the protective shield...I've seen in a tutorial for replacing the TCON board of another Sony TV model that there are some heating pad for dissipate heat producesmby the board components. Are heating pads required for the TCON board of this model?? Is it possible that the technician forgot to put the, back when re-assembling the TV??
Any help will be really appreciated..

[lenny1972]

Re: Sony KDL40S2000 TCON board issue...

I've made a brief video showing the problem. I hope it helps the experts in identifying the fault TCON board component.

https://www.youtube.com/watch?v=cmxk...e_gdata_player

[budm]

Re: Sony KDL40S2000 TCON board issue...

https://www.badcaps.net/forum/showth...ng+LN32B540P8D

You can use canned air duster up side down to gt cool air, Spary it on QTIP then touch the suspect part with the QTIP to pinpoint cooling.

[splitcrete]

Re: Sony KDL40S2000 TCON board issue...

Sounds like a tab bond problem to me.
A bad tab bond will blow a t-con fuse.
Try reseating t-con ribbon cables they have very small contacts.

[lenny1972]

Re: Sony KDL40S2000 TCON board issue...

https://www.badcaps.net/forum/showth...ng+LN32B540P8D

You can use canned air duster up side down to gt cool air, Spary it on QTIP then touch the suspect part with the QTIP to pinpoint cooling.

Thanks a lot for the link and the tips, I'll try to do the way you suggest..I'll get back to you as soon as I found the fault part.

[lenny1972]

Re: Sony KDL40S2000 TCON board issue...

Sounds like a tab bond problem to me.
A bad tab bond will blow a t-con fuse.
Try reseating t-con ribbon cables they have very small contacts.

I've already tried to reseat the tcon ribbon cables with no success. It's probably the case of a bad component

[lenny1972]

Re: Sony KDL40S2000 TCON board issue...

https://www.badcaps.net/forum/showth...ng+LN32B540P8D

You can use canned air duster up side down to gt cool air, Spary it on QTIP then touch the suspect part with the QTIP to pinpoint cooling.

Sorry, but how did you suggest me to use the air-duster us side down?
I've bought a freezing spray specific for testing electronic components and there is no any advice to do that....Is it probably because you referred to a generic "air duster spray" and not a specific product??

[budm]

Re: Sony KDL40S2000 TCON board issue...

You can use air duster as cold spray by using it upside down, I used to use Freeze spray for electronics troubleshooting but I can get 6 cans of air duster from Costco for $16, much cheaper than the freeze spray.

[lenny1972]

Re: Sony KDL40S2000 TCON board issue...

You can use air duster as cold spray by using it upside down, I used to use Freeze spray for electronics troubleshooting but I can get 6 cans of air duster from Costco for $16, much cheaper than the freeze spray.

I see

[lenny1972]

Re: Sony KDL40S2000 TCON board issue...

I see

Using the ice-spray I found the bad components in my TCON board.
It's marked with L1 and it seems to be an inductor (rounded in red in the picture).
The mark on the body says "100 M61"..
I'd like to try to replace it but i really don't know wich is the specification (100uH?? or what??)
Could you please help me in identifying it?


p.s.: Are there specific instructions on how to desolder the old and solder the new inductor? I'm a newbie

[budm]

Re: Sony KDL40S2000 TCON board issue...

I think you really need to pinpoint cooling to be sure, I have some doubt that the inductor is bad, you can check the resistance to see if it is open when it is bad. You may want to roll a tube card board around the inductor then spray other components close by to see if you get the change in the circuits.

[lenny1972]

Re: Sony KDL40S2000 TCON board issue...

I think you really need to pinpoint cooling to be sure, I have some doubt that the inductor is bad, you can check the resistance to see if it is open when it is bad. You may want to roll a tube card board around the inductor then spray other components close by to see if you get the change in the circuits.

I used a Q-tip (and put it in contact with the inductor) and found it is for sure the fault component.

Can yoo give me some advice in order to understand which is the right value of the inductor? Is there a way to know it by testing the component with a simple mulimeter ?

[randtek]

Re: Sony KDL40S2000 TCON board issue...

I know of no reliable inductance testing method using a multimeter. You will probably have a much easier time finding a new TCon board than identifying that inductor. I am pretty surprised that the inductor is the problem, as intermittent inductors, while not impossible, are EXTREMELY rare. If you are able to identify the value of the inductor, your next challenge will be to find a replacement that will fit in the alloted space. If you choose to replace the TCon board, the part # I show in my records is 1-789-499-11.

[martyparish]

Re: Sony KDL40S2000 TCON board issue...

Is it possible that the cold transferred to a nearby part? Have you tried "not" touching the inductor, but nearby components?

[lenny1972]

Re: Sony KDL40S2000 TCON board issue...

Is it possible that the cold transferred to a nearby part? Have you tried "not" touching the inductor, but nearby components?

Yes, I've tried to touch nearby components...No other components when get cold (using the freezed Q-tip) solve the display problem..

[lenny1972]

Re: Sony KDL40S2000 TCON board issue...

Yes, I've tried to touch nearby components...No other components when get cold (using the freezed Q-tip) solve the display problem..

I've done a second check on the TCON and it seems to be the fuse.
It was the component that the tech assistance guy replaced on the TCON.
By freezing it the problem solved..Is it possible??
As far as I know, the fuse can work or not..it seems really strange to me that if if I freeze it the display problem disappear..
How can I find the fuse value (the TCON BOARD is marked 400WSC4LV0.4)??

[budm]

Re: Sony KDL40S2000 TCON board issue...

Fuse is either open or show less than 1 Ohm resistance. You can check the resistance when it is heated and when you cool it.

[tom66]

Re: Sony KDL40S2000 TCON board issue...

If it was the fuse accidentally replaced with a auto-resetting fuse, I could see this happening.

[kc8adu]

Re: Sony KDL40S2000 TCON board issue...

from the looks of it thats what happened.so too low value and its tripping or something bad(mlcc?) on that line?

If it was the fuse accidentally replaced with a auto-resetting fuse, I could see this happening.

[tom66]

Re: Sony KDL40S2000 TCON board issue...

Just too low of a value, and it gets hot. As it gets hot it increases in resistance until the T-con doesn't work properly. Proper fix is to use a real SMD fuse.