FOur kids use for various activities and my wife just sent me a text stating that the pad won't stay powered on unless it is connected to a power source. Needless to say the iPad has been slightly abused in the past from kids dropping it, the screen has been cracked and replaced by a vendor, and we have it in a rather indestructable case to keep it from future damage. Is this a hardware issue from the prior abuse or rather a possible virus? Any ideas?