Help diagnosing Samsung BN41-02844E main board

[Davi.p]

model: BN41-02844E

I want to connect serial debug line, but the usual scheme of 4 contacts for pins is present 3 times, under the board top part, if connect them always in the same way GND, RX, TX, i obtain the same very short log in right snd left ports , the center port gives me no output, i whish to be able to enter some menu or even the service menu trough this.. could anybody address me how to? Later i will swap RX-TX in the center port but almost suremy is disabled..
thanks

[lotas]

It's not that simple, your UART is blocked by software, you need to find dump eeprom 24C512 with debug activated.

[Davi.p]

Yes, thanks, i forgot that, in some early 2010 years models i was able to modify a certain eprom to enable the debug, now it's almost impossible, but i have another board same BN41 where i can get the unlocked uart programming, the wish to do it is absent, also when i remove heatsink remain.a small damage by pliers.. not precise pliers.. board is almost brand new and i want to sell it as is..

apart this, which one is the debug port?

q

[Davi.p]

Ok later i will note the keys sequence to activate debug mode in SM..

[lotas]

All Samsung motherboards have a closed uart, it is activated via the service remote control in the service menu or look for eeprom from such a chassis with an activated uart.

[Davi.p]

yes i know, now the other mb is stuck in a Mass production test and remote is disabled, i have to wait the test ends

[Davi.p]

i successfully activated the service mode: POWER OFF (Stby) - Info, menu, mute, power - wait 45sec - arrow down, enter, arrow down, enter, enter, left, return, return, return - POWER OFF

now i was on the central port, this is the TCon software debug..

now i watch US Open tennis final then i change port...

The board appear to be in protection mode about tcon job, but it is not visible clearly by log, when connected to LCD it boot loops with no image, the other board works correctly, the screen is slighy defective.. this boards produces all voltages on tcon section when LCD is diisconnected..

[Davi.p]

Left port from the back is the main software log, it is long kilometers, it never stops, also when put in the stby,..