Samsung UE65RU7090UXZT main board issue no video out. BN94-14180M

[alltvrepairs]

Hi,

I have confirmed that I have a mainboard problem.
I have tracked no hardware issued on board so might be a software dump required.

I have searched a bit but wasn't able to find anything for my screen:

Here are some more details:
Panel: cy-nn065hgev1h
Main: BN94-14180M P08F

Your help much appreciated!

[Diah]

make jumbers between this 2 points feedback FB, then disconnect one LVDS at time.... see which half of screen will show image

[alltvrepairs]

Have checked these points before and with both LVDS disconnected there was 3.3v and 0v,
However I have tried 2 other boards similar but different BN94 number and got a picture. 1 perfect pic (From UE55MU6400) and 1 almost B/W with lines.

Got the Panel no from Service Mode for the good picture board and tried to update the second (B/W pic) board as its identical board but didn't find a matching model out of all those different displays in SM.

[alltvrepairs]

Anyone has the correct spi dump for this board?
Thanks!

[Davi.p]

Working software and no output video tends to be bad tcon integrated to main board.. maybe the data on the tcon spi eprom, you can import that one on the board that displays ok

[alltvrepairs]

make jumbers between this 2 points feedback FB, then disconnect one LVDS at time.... see which half of screen will show image

Hi, interesting as didn't know about this trick. Did this but with both connectors out and points shorted, the tv start rebooting sequence. Trying each lvds makes no difference.

I have swapped ic1603 ic1604 with a working but wrong panel board but still same problem.

The tcon is part of the cpu so no more places to look at. I have just ordered a replacement board with same specs and display.

I have managed to get the dumps for both ICs. Will post them later in the correct section.

[Davi.p]

no software issue then, short circuit in tcon power supply circuits, maybe a small cap, you can test also mosfets & diodes

[alltvrepairs]

no software issue then, short circuit in tcon power supply circuits, maybe a small cap, you can test also mosfets & diodes

For curiosity, do you still remove the EEprom / SPI chips from main board to read / write? With closeby SMDs sometimes becomes a bit risky job. I am aware that the programmer cannot power supply the whole board.

[Davi.p]

i .always try to read with clip, in certain situations it does not go, but it's mandatory a verify after.