Ipad Air Plugged In But Not Charging. After that check the rest of the charge circuit MOSFET Coils etc. Make all the reboot Windows jokes you want but sometimes bad bits get stuck and need to be flushed out.
There could be quite a few reasons why your iPad may refuse to charge. It is possible that your iPad could not be charged because the charging port is distorted or obstructed. Follow these steps and try again after each.
If that is good then a fresh battery Tristar would be the next steps which you have already done.
If not continue trying methods left. Sometimes the problem is not with your iPad but with your electrical source. Follow these steps and try again after each. Charge your iPad using the charging unit and always plug the charger into a decent surge protector never straight into the wall if possible.