Tablet will not turn on

On the night before, I used my tablet normally, turned it off and left it to charge overnight. Upon waking up to use my tablet, the screen indicated it's 100% charge display, but when I went to press the power button, the display went black, and would not turn on after repeated pressing of the power button. Neither the LED lights are on BTW.

I have tried several methods such as pressing the power button in conjunction with either the up/down volume button or pressing the screen (while plugged in and unplugged). My last attempt was to gently disconnect the battery strip(?) And reconnect it, but to no avail.