Sometimes mine is the same.Wait a long time.Maybe the power is not enough to turn on the machine. Once I couldn't turn it on, I pressed the volume button and the power on button (blindly) and it turned on
Charge it for a while to see if it can be switched on. If not, check whether the data cable is broken. If the data cable is not broken, it may be that the iPad is broken. Go to the after-sales inspection