Chosen Solution

Sound is on when charger is connected, and/or receiving emails, messages etc. Tried rebooting with Power On/Off button + Home button… nothing is happening. Do I need to change the screen?

Yes, when you dropped the iPad the LCD itself sounds like it blacked out. This happens more often than you’d think. You’ll need this part. iPad Pro 9.7" LCD Screen and Digitizer Follow this guide. iPad Pro 9.7" Screen Replacement