If you can remove the battery, then do so. Try other chargers and other batteries if this is an option.
Make sure to plug it in and give it time to charge. If the voltage is too low in the battery, the phone or tablet will not turn on even if it is plugged in.
Google to see if your make and model has any tips such as HARD or SOFT RESETS.
If it still won’t turn on, let one of our experts take a look.