Samsung UE48J6200K - No image but sound

[Francesc V.]

Hi:

This TV turns on and it can show picture for some seconds (sometimes minutes) then picture freezes and fades away. What I've seen so far is that the T-Con (BN41-021101A) starts with three leds on, but as soon as led3 turns off, just 12V and 3.3V (the bold ones) remains in the PCB but all others disappear.

If I remove the 2 bellow ribbons, LED2 never turns on. I was trying to look for the "T-CON ready" pin to shorten with 3.3V and then test just the TCON without the panel (haven't found it yet)

Not sure how to proceed here..............how can I know whether it's a TCON issue or a faulty panel?

Any ideas, more than welcome.

Regards,
Francesc.

[EazyBone]

Pictures of all board would be helpful. Generally freezing picture and distortion are because of main board failure. This is a TCON/main together I assume?

[Francesc V.]

This is the whole mosaic. I am assuming TCON is failing because it looses voltages after some seconds after the TV is switch on. the "SMART TV" logo appears, and later on clear picture or clear menu...........then image fades (it can last some seconds or from time to time some minutes).

[Francesc V.]

HI:

Some follow up with my investigations trying to unprotect TCON and isolate the problem.
This PCB doesn't have any TCON-RDY or similar pin as shown in other videos to unprotected it..........so I've seen a similar Samsung TCON that was unblocked with the following method and I've just tried it.

It seems (DO NOT TAKE it as an statement) that shortening PIN 28 (left ribbon from left to right) and PIN 28 (right ribbon from right to left) that TCON also gets unprotected. TCON turns on without panel ribbons connected (although picture shows them connected).

With panel ribbons disconnected and TCON unblocked, only main LED 12V and 3.3V led are lighting (missing Vdd light).........a new TCON is on its way.


I've ordered same TCON model but it says 55inches..............is it as easy as moving the marked resistor from 55' to 48' before installing and give it a try?


Regards,
Francesc.

[lotas]

You will also need to transfer the spi flash W25Q40 from its original one to a new one (all the settings of your panel are stored in it).

[Diah]

LED 3 power supply from, AVDD, Voff.. mean there are issue to cut off.

[Francesc V.]

You will also need to transfer the spi flash W25Q40 from its original one to a new one (all the settings of your panel are stored in it).

Thanks lotas. I will have a look. I am marking the one I might think you are refering to.........could you please confirm it?

[Francesc V.]

LED 3 power supply from, AVDD, Voff.. mean there are issue to cut off.

Yes.......it seems so. But I am just an idiot trying to find the issue :-)

Also, the PIN28 thingie doesn't seem to work for this TCON model..........(led2 doesn't turn on with panel ribbons disconnected; not even for seconds-minutes as the original fault).

[Diah]

LED 2, are feed back if the panel turn on so the secondary power supply of the processor and RAM of the t-con will be present

[lotas]

Thanks lotas. I will have a look. I am marking the one I might think you are refering to.........could you please confirm it?

Yes, he is the one.

[lotas]

Take a high-quality photo of this area.

[Francesc V.]

LED 2, are feed back if the panel turn on so the secondary power supply of the processor and RAM of the t-con will be present

Ok.......so that explains that this part doesn't turn on if panel ribbons are not present or card is tested isolated by injecting 12V in the input.

Any idea how to force/unblock that TCON model in order to simulate that feedback?

[lotas]

Any idea how to force/unblock that TCON model in order to simulate that feedback?

I asked you to take a high-quality photo.

[Diah]

Ok.......so that explains that this part doesn't turn on if panel ribbons are not present or card is tested isolated by injecting 12V in the input.

Any idea how to force/unblock that TCON model in order to simulate that feedback?

disconnect the MB from PSU.... also disconnect the LVDS from T-CON side..
turn on and find 12V VCC on the PSU to feed the T-CON Fuse direct with it.

[Francesc V.]

I asked you to take a high-quality photo.

Yes. Hopefully this one is better. I've found a TCON_READY pin that has 3.3V when 12V injected in the fuse. I guess I need to find another point in the PCB to shorten it. Ground this point doesn't make any difference (no Vdd,,,,,,)

disconnect the MB from PSU.... also disconnect the LVDS from T-CON side..
turn on and find 12V VCC on the PSU to feed the T-CON Fuse direct with it.

Yes.........right now it's on the table isolated.

[lotas]

Connect RM15 (put a jumper) remove the black wire..

[Diah]

Yes.........right now it's on the table isolated.

MY Post and my way to have it in Tv with panel connected.... alone on table what you will reach ?? nothings

[Francesc V.]

MY Post and my way to have it in Tv with panel connected.... alone on table what you will reach ?? nothings

This testing I have it pending. I need my wife not to be at home as the test requires "some space". :-)

I'll let you know the outcome during the weekend.

Thanks Diah for this suggestion.

[lotas]

So place the jumper as described above and supply 12 V to the t-con, this is without a panel, the panel is not needed here and check the voltage at the output.

[Diah]

So place the jumper as described above and supply 12 V to the t-con, this is without a panel, the panel is not needed here and check the voltage at the output.

LOL.... lotas T-CON never being Voltage or currents,,, so what are all these muscle training you are showing here... LOL.... T-CON must an Panel connected... and must too the 12V VCC from it own PSU to match Freq. .... this is MUST if one want to handle T-CON in case he didn't have in hand Oscilloscope ... end of muscle training show.