[IDEA] [Tut] How to turn off Backlight of a Waveshare 7" HDMI LCD using GPIO and screensaver

[hoeb]

I am sorry for posting this here. But it was the only thread i could find about moding a waveshare screen. I also have a waveshare screen, but not the 7" but the 13.3" with case.
I am looking for a same solution which is made here, but than for the 13.3" screen.
Unfortunally for me waveshare doesn't added the modification on his website, which the did for the other non case screens (https://www.waveshare.com/wiki/File:PWM_control_backlight_manual.pdf).

On the other boards the LED driver is located. But my board is different and i don't know where to start where the LED driver is located. I know a few things of electronics, but need help from the experiance guys. Is there somebody wo can help me?

This is the top side of my board


When i flip it, there are the buttons to control the menu and the soldering for setting the voltage for the board