Chosen Solution
When I power on my phone the Sony logo flashes up for 2 seconds before going dark and after that the screen is only visible in torch light, I have replaced the LCD screen and don’t know what it could be or how to fix it. (this all happened after dropping it in water)
Looks like the backlight circuit has fried, you will have to look at it under a microscope or send it to a micro soldering repair shop!
