Galaxy Tab A 10.1 powers on but screen is black and unresponsive
I have a friends Galaxy Tab A 10.1 the screen just went black. I powers on and responds to touch on the back and apps keys. I can't even get it to turn off. The screen is completely black and doesn't respond to touch. I can't get it to turn off, I tried holding down the power button but it was still on. I left off of the charger over two nights then I plugged it in and charged it for about an hour and tried the home/power/volume up but nothing still black screen, and still sounds from back and apps key. What are the steps to troubleshoot this problem and possible causes.