Original post by: Gregory Harris ,
Jonathan, iPads and iPhones have an integrated chip (IC) called the Tristar chip that governs USB charging and recognition. If you have replaced both the battery and charge port and still no charging then it is possible that this Tristar chip has gone bad. That's not uncommon since they are sensitive to voltage surges or "dirty" voltage that most often occurs when using cheaper 3rd party charging cords. Apple charging cords and certain higher quality 3rd party charging cords have components that protect against bad voltage. The Tristar chip can be replaced. It requires microsoldering equipment and expertise though.