The last thing I would do is wipe it and fool with the OS, especially if your new to BB's.
the wall charger may be simply overheating and shutting off. Most Lithium batteries have a charge limit to prevent over charging. the wall unit has a conversion to the 5volts nessesary for the blackberry's battery. It also has the nessesary circuits to limit. I would try a new wall charger before doing anything else. The PC charge relies on the battery to do it's own limit.

good luck and welcome to the forum