Hi! If there is a bad electronic component, like a device in short circuit, it will try to start and detects the short, and turns off. If there is a defected charging circuit, it will happen the same or to show dead after a total discharge. OR, and "AND" the last ones, plus if the battery is under the operation level, some models of tablets are not able to start. First step is to charge the battery and to see if the tablet is able to start and charge, or if there is a bad component because there is a wrong behavior.
The following video was recorded for technicians with this kind of problems: https://www.youtube.com/watch?v=2ggQU3E0...