luevano13207, consider changing the dock connector. If it was an over voltage issue it would most likely destroy your charging circuit before reaching the battery. The overheating could be caused by a failed/damaged charging coil. Use these guides to work on your phone. Check for any physical damage, or if you have the knowledge and tools, check for function. You want to start by checking 3 inductors. For that, of course, you need a multimeter, or at least an ohm meter, to check for continuity. I hate to refer to those as fuses, but they most certainly control part of the charging circuit. First one is reference designator L3, it is a FERR-120-OHM-1.5A inductor. L4, right below it , has the identical value. Next would be the charger inductor L28 2.2UH-1.8A-155MOHM. All of these are pretty much available at mouser. com or digikey.com. Check the Diode D604, located just above L28. Purchasing replacement boards that are locked or water damaged are nothing but buying someones problems and would not be a good choice at all. Hope this helps, good luck.
Hope this helps, good luck.