Mi TV 4 Pro-Samsung Panel LSC550FN20 - Video problem, backlight and Audio works fine.

[SolarFlare]

Hi,

My barely 3 year old TV has stopped displaying video, although the video output comes for a few seconds after turning ON which displays the manufacturers logo then shows the home screen (all this with some blue flicker) then the video goes blank and the screen is dark blue with the backlight on. The audio output works perfectly and the TV also takes in voice commands(smart TV).

The TCON board has the following Chips -
Samsung VTU63A0
RT6939 - 2nos.

and all these chips are getting real hot within a minute, I dont know if this is normal.

I have attached the pics of the same with the voltages at the respective points also.

I desperately need help.

Thanks!

[dskall]

Re: Mi TV 4 Pro-Samsung Panel LSC550FN20 - Video problem, backlight and Audio works f

Looks like a short or bad panel. Check all the little brown caps on panel board and t-con for shorts.

[SolarFlare]

Re: Mi TV 4 Pro-Samsung Panel LSC550FN20 - Video problem, backlight and Audio works f

I checked all the capacitors in the TCON and there is no short.... how do I check a short in the panel?

the panel board is integrated with the TCON. Please have a look at the pic attached....
also any place I can get the datasheet for RT6939?
seems like they made a TV with all the obsolete parts they could find and i bought it.

[jimbofz]

Re: Mi TV 4 Pro-Samsung Panel LSC550FN20 - Video problem, backlight and Audio works f

i tried everywhere for purchase of these chips .
in the end i gave up and scrapped tv sorry ,
perhaps someone can supply one from a scrap panel

[SolarFlare]

Re: Mi TV 4 Pro-Samsung Panel LSC550FN20 - Video problem, backlight and Audio works f

i tried everywhere for purchase of these chips .
in the end i gave up and scrapped tv sorry ,
perhaps someone can supply one from a scrap panel

oh ok... what could be the problem in my case? I checked the caps and they all seem to be fine i.e. no shorts i am lost as to what could be the problem

[Diah]

Re: Mi TV 4 Pro-Samsung Panel LSC550FN20 - Video problem, backlight and Audio works f

did you checked the BL working or not ?

[SolarFlare]

Re: Mi TV 4 Pro-Samsung Panel LSC550FN20 - Video problem, backlight and Audio works f

did you checked the BL working or not ?

yes the backlight is working fine

[SolarFlare]

Re: Mi TV 4 Pro-Samsung Panel LSC550FN20 - Video problem, backlight and Audio works f

did you checked the BL working or not ?

What you suggest I could do??

[djmka]

Re: Mi TV 4 Pro-Samsung Panel LSC550FN20 - Video problem, backlight and Audio works f

Hi SolarFlare,
Did you ever get to the bottom of this issue? I have a JVC LT-40CF890 which is displaying the same symptoms as your television. The backlights come on, sound can be heard, I can change the volume etc...,but no image. The chip labelled Samsung Display VTU63A0 NKPBWS00 2012 gets hotter than I would expect.

[TVAddict]

Re: Mi TV 4 Pro-Samsung Panel LSC550FN20 - Video problem, backlight and Audio works f

Don't hold me to it, but it could very well be that the panel itself is the problem in both TV's, maybe a failing cof, my suggestion is to try the tape method, requires a bit of patience and logical reasoning, sometimes it pays off, keep in mind though if you do manage to get the picture back using the tape method, in most cases it won't be a perfect picture, there will be some visual imperfections.

[stav242]

Re: Mi TV 4 Pro-Samsung Panel LSC550FN20 - Video problem, backlight and Audio works f

Don't hold me to it, but it could very well be that the panel itself is the problem in both TV's, maybe a failing cof, my suggestion is to try the tape method, requires a bit of patience and logical reasoning, sometimes it pays off, keep in mind though if you do manage to get the picture back using the tape method, in most cases it won't be a perfect picture, there will be some visual imperfections.

Hi, i have same symtoms on similar unit.

will the tape method still work with this integrated TCON, i dont see any CLK lines i can tape off on the LVDS connector and all TCON / buffer board connections to panel are bonded type.

looks like my only option to cut CLK is to physically cut the copper tracks on the board to try and identify if there is a panel short issue.

like the OP ive checked shorted Capacitors, have found some black resistors at 0.4ohm - but dont have a circuit schematic to confirm what they are. They connect to the `Samsung Display VTU63A0` IC. - would be nice to be able to confirm that the DC-DC is working before cutting the lines and permanently damaging anything.

anyone have a circuit diagram / pinout of VTU63A0 ?