The first step would be to restart the system to see if that allows the tablet to fully turn on. If that does not work, the next step would be to let the tablet die and then to charge it again, this might reset the software in the tablet and fix whatever bug is causing it to not fully restart. If this does not work the battery of the device might need to be replaced.
Chances are that the charging port has either been altered so that the charger is no longer compatible with the device or the charging cord has been compromised. You can plug it in and jimmy the charger in the port it might make the necessary connections. If this does not work the next step would be to try another charging cord to see if that fixes the problem. If the device is still not working, the charging port might need to be replaced.
The first step in fixing this issue would be to restart the system. Sometimes there is a glitch and when everything is reset the glitch is taken care of. If that does not work the screen may be compromised and needs to be replaced.