Cube mix plus unable to start

i was using the tablet with about 20% battery left but i suddenly crashes. i taught it was low batt or too hot, after fully charging(with the LED light indication=green) the tablet the next day it was unable to start up. No mater what combination of the buttons(even the reset button) i pressed it still doesn’t start up, but it has the red LED light indication. Anybody knows whats the problem, thanks.