Will not power on past the charging screen
Yesterday I let my iPad fully run out of battery, a rare occurrence because it usually only gets down to 90% battery before I put it on the charger again. I plugged it in, and it kept looking like it went to the screen to type in the passcode, but then restarting. Now, when the iPad is connected to a charger, the battery icon only shows when i press the lock button at the top. The lightening cable icon is no longer present when I plug it in vs not plugged in, so I know the cable is good.
I have tried a hard reset, holding down for as long as 2 minutes. Also, my computer will not recognize my iPad when it is plugged in, as it currently has been for the last 2 hours. What can be wrong with my iPad? It won't go beyond the low battery icon screen.
iPad Air 2, iOS 12