Hi, there may be at least three issue regarding this symptom. (1) The charger / USB cable is not working (2) the charging port is broken (3) the battery is dead So how to troubleshoot this problem? (1) change to another charger (2) change USB cable (3) finally if none is working, change the battery. It would cost around USD $20 I've try to use hardware reset / factory reset (press Power button and the Home button simultaneously) but both step fail. Last option, get a new phone.