My tablet not charging or coming on

My best answer would probably limit it to 3 possible causes. 1) Charging port for the device has gone bad, whether it be broken inside and have missing pins, or actually being separated from the board. 2) Maybe a dead battery, but I suspect that if it had a dead battery it would still come online when you plug it in. Or 3) The charger itself has gone bad. This should be easy to test depending on the device. take a multimeter and hook it up to the "-" and "+" and see if the readings match the data panel on the back.. Hope this helps ya.