Samsung UE55H8000SZ with TCON BN41-02112A

[michdundee]

Hi all,
I'm facing a issue... hope you could help me. I have a T-CON board BN41-02112A from Samsung 55inch Curve TV.
I have just only 2 status blue LEDs ON since LED3 is off. I have tried to test some test points but VON is NOT OK very close to 0V. Is there someone that can help me on the debugging the issue? I'm supplying the board from an external 12V voltage source.
Thank you in advance.
BR,
Michele

[lotas]

Without the panel, 3 led will not light up.

[CapLeaker]

And I don’t think you can troubleshoot anything much with out having all of the TV.

[michdundee]

Hi all, thank you for the quick reply. With the TCON connected to the mainboard and the panel the LED3 is not turning on too and I have no sound and no picture just backlights. from where can I start to debug the issue?

[lotas]

Place a jumper on T-con F_R< --------->F_L, disconnect the cables going to the panel one by one and check the non-working side.

[michdundee]

Place a jumper on T-con F_R< --------->F_L, disconnect the cables going to the panel one by one and check the non-working side.

Hi Iotas, what do you mean for "place a jumper" F_R <---> F_L? thank you in advance

[lotas]

Hi Iotas, what do you mean for "place a jumper" F_R <---> F_L? thank you in advance

F_R <---> F_L

[bohaboha]

,
why are you supplying the board from an external 12V voltage source. is the power board not working?
and please upload pictures of the set and all the boards

[michdundee]

F_R <---> F_L

Hi Iotas, what is causing the short between F_L with F_R? I will try it for sure.

[michdundee]

,
why are you supplying the board from an external 12V voltage source. is the power board not working?
and please upload pictures of the set and all the boards

Hi Bohaboha, trying to supply the board for a raw sanity check. I was expecting to have LED3 on too (the boost section) but I guess there are firmware dependencies. Another detail: when I try to turn on the TV the power state red LED is blinking slowly 4 times.

[michdundee]

,
why are you supplying the board from an external 12V voltage source. is the power board not working?
and please upload pictures of the set and all the boards

the other boards attached

[lotas]

Hi Iotas, what is causing the short between F_L with F_R? I will try it for sure.

F_L and F_R are feedback. If you disconnect any cable (left or right), then the panel and t-con feedback is disrupted.

[michdundee]

F_L and F_R are feedback. If you disconnect any cable (left or right), then the panel and t-con feedback is disrupted.

Hi Iotas, ok I see thank you for the explanation.

[Diah]

Hi Bohaboha, trying to supply the board for a raw sanity check. I was expecting to have LED3 on too (the boost section) but I guess there are firmware dependencies. Another detail: when I try to turn on the TV the power state red LED is blinking slowly 4 times.

so yours main boards try to boot but it couldn't... you need to test first PS_ON signal >3V on the PSU sockets first.., if yes you have and other V PSU send back.. then you have issue at the panel.

[michdundee]

so yours main boards try to boot but it couldn't... you need to test first PS_ON signal >3V on the PSU sockets first.., if yes you have and other V PSU send back.. then you have issue at the panel.

Hi Diah, I have a stable 3.3V on PS_ON. is that ok?

[Diah]

Hi Diah, I have a stable 3.3V on PS_ON. is that ok?

yes its ok, but what about other V the PSU generated... list them over here with pin name

[michdundee]

yes its ok, but what about other V the PSU generated... list them over here with pin name

see attached picture too

2	3.26V	1	0V
4	3.26V	3	3.25V
6	3.26V	5	0V
8	3.07V	7	12.83V
10	3.16V	9	12.83V
12	4.81V	11	12.83V
14	3.3V	13	12.83V
16	0V	15	12.83V
18	0V	17	0V
20	12.83V	19	12.83V
22	0V	21	12.83V

[lotas]

see attached picture too

2	3.26V	1	0V
4	3.26V	3	3.25V
6	3.26V	5	0V
8	3.07V	7	12.83V
10	3.16V	9	12.83V
12	4.81V	11	12.83V
14	3.3V	13	12.83V
16	0V	15	12.83V
18	0V	17	0V
20	12.83V	19	12.83V
22	0V	21	12.83V

Why do you need these voltages now, your 3 LED on the t-con is not lit, put a jumper and check your panel by disconnecting different cables.

[michdundee]

Why do you need these voltages now, your 3 LED on the t-con is not lit, put a jumper and check your panel by disconnecting different cables.

I will do it in the next days thank you. I will let you know the outcome of the test.

Diah was asking the table above and I have provided the list with related values.

[lotas]

If there were problems with the power supply, then the backlight would not work and 1 LED (12v is the norm) on the T-con would not light up.