sudomod

Sounds like you made a boo boo there, NEVER plug things on when there is power. you likely killed the backlight or the LCD mcu itself. Time for a new LCD I'd say.

Sorry for the late answer, effectively, I didn't manage to do anything with it, I repared my first back camera screen and everything's ok ! ILI will go to trash
thanks, making mistakes will make me better in the future i guess...