First Of All Have You Tried To Turn Of And On The Device ? Maybe You Should Try To Go To Settings, And Then Go To Sound. Since Phones Have Different Volumes For Example It Has A Ringtone Volume, Alarm Volume, And the The Music Or Sound Audio. Try Charging It All The Way And Check For Updates In Settings.
Maybe I Have A Solution, Try The Following Steps : 1. Take Out The Battery 2. Now Once you took out your battery click and hold the power button for 30 seconds. 3. Plug Back In The Battery, And Connect The Charger And Let It Charge For About 10 Minutes Or More To Be Sure. 4. Ok, Now Try to Turn On The Computer If It Dint Help, I Am Sorry About It. You Should Try To Take It To A Repair Place.