The feeling is very bad…

I find the problem of the back light. It is because I am using screen-chip PWM to control LED brightness. When I send command to the screen, it do not action at all, keep output 0 to the LED power control chip.

Looks like the problem is the screen chip accept my command but ignore the parameters. weird issue, I have worked on this over three days but no way out.

…Emm, maybe I need change another screen and try …