Toshiba 50L2333D TV: Unable to Adjust Backlight - Voltage Output Issue, Transistor Replacement

Hello, I found this TV Toshiba 50L2333D tv works ok beyond the ability to adjust the backlight. I checked the voltage and at the output of the LEDs I have 79-82V, the lack of constant voltage only still jumps, the markings on the board say that 111V should be there. I had a similar problem with the input power jumping 220-250V voltage (I do not know from where the 250V was taken but the meter showed it) after replacing the 3 transistors on the board from the power supply voltage on the input is already fixed - not jumping.

I replaced the transistor backlight but it did not do anything. Tv turns on and works normally but I can not adjust the brightness of the matrix.

By arrow I have marked the output from the backlight to the matrix, and in the circles I have replaced so far.



Have any of you encountered such a problem?

Hello

Read on Elektod (or on the Internet) how the brightness control of LCD screens with LED backlight, but also CCFL, and EEFL is working. (analogue and digital brightness adjustment, PWM etc.) DC voltage for LED blocks is to be stable but it does not decide on the brightness adjustment of the matrix, only signals and voltages sent by the motherboard processor to the inverter resulting from the user's OSD commands, and these first .... check ... (...)