Samsung UE50RU7170 not booting /no picture

[Aeisens]

Dear all,

My issue is the following:
Tv suddenly started to make Strange things and went out. After disconnecting power and restarting, it tried to start but failed. After each attempt it got worse and worse. Now only the Stdb light is on and it is not booting.

I checked the power supply -> Backlight on when disconnected from mainboard, so I guess Power supply is ok.
Additionally the upper right part of the main-board makes some whistling noise -> probably issue there and therefore issues with booting

Question 1: Where should I start to Look for the faulty part on the mainboard? BN94-14112H

As I Could get my hands on a used mainboard from the same model (Both UE50RU7170UXZG but mine is Version No. 02 / URU 7100, while spare Part is from 05/URU7100) I tried a new Mainboard.
Result: TV booting + Sound from settings, but no picture.
when comparing the boards I realised they were different Versions (BN94-14112H vs. BN94-15022A)

Question 2: How to Check whether my issues with the new board are caused by different Version, or by Further issues with my TC Board or Panel?

I hope somebody can help me.

[lotas]

Try to move SPI Flash W25Q80V_IC1603 (T-CON firmware) from the original board to the new one.

[Aeisens]

Thanks for the Input.
I tried it but still the same issue.
could I Try to Flash new Firmware with USB?

[lotas]

Are the positional resistors in the T-CON area installed identically on the motherboards? How can you install a new firmware without an image? Install a jumper and try to connect the LVDS cables one by one and see if an image appears on which side.

[Aeisens]

You mean the marked Area?

I Could Download Firmware on usb and Hope to find a Video Tutorial what to Click when —> no Picture needed

with the Jumper I got. on the Left side a white screen

[Diah]

50 size panel are rubbish over all brands.