I was just using 21 plus that I bought half years ago. It just turned black all of sudden. It charges correctly, I tried turning off, and nothing but the alarm goes off at the morning. Do I need to change the screen?
I suggest reaching out to a Samsung authorized service center, like uBreakiFix, to have you phone evaluated. Diagnostics are typically free. They will be able to tell you what went wrong and provide options for repair or replacement.
You might also try (if you haven't already) holding the volume down key and the side key simultaneously to see if a hard reboot would help. Most likely will not and should use the above suggestion, but it's worth a try.
