Chosen Solution

I replaced the LCD screen and the digitizer. I can see the LCD light up in the back of it but it is black on the front I drained the battery and disconnected it before any work I also replaced the on off switch This is on a 2560 model

It might just be the new LCD that’s not working, or you might’ve damaged one or several of the LCD-related components on the logic board. Do you have another LCD that you can try?