My Lenovo tablet turned off and never came back on.

@dottie12321 double check your charger. Check the charging port and make sure it does not have any “pocket Lint” or other debris in it. A few puffs of compressed air should clean it out. Connect a USB ammeter between the tablet and the charger and see how many amps your tablet pulls. Let us know what those values are. If none of that will yield any result, it will be time to open it up and check things out a bit more in depth. Check the connections of the charging port and make sure you have power going to it. Something like this video will at least get you into it. This Manual should also help.