Does it work if you use the USB cable and plug it into your running computer? If still no, then you should try another cable. If it still fails, you have to use process of elimination. Verify you have AC power where you're plugged in (dont laugh, iit happens). If yes, then try another charging cube or, if you have a voltmeter, verify it is outputting the proper voltage. If it still fails, you're probably looking at a defective phone. If it's in warrantee, get a replacement. If not, then decide if you want a new phone or (if your phone has removeable battery) get an external charger.