What may be wrong with my phone for the display to have stopped working?

Hello,

The problem with your phone is just flex problem, the flex on the screen of your phone is weak or worn out, this is a common problem among slide or flip phone.

What you need to do is to replace the flex on the screen of your phone, you can get this done by going to any local phone repairer within your vicinity to help get it fix or replace.

Once the flex is replace, your phone display problem is solve and the screen will start displaying.

Take care.