12-08-2012 05:35 PM
Hi and Welcome to the Community!
Please try this sequence...note that, throughout the entire 4h15m process, your BB must remain connected to a known-good wall charger (not PC USB):
This has been known to "kick start" some BBs.
It is also possible that your battery or BB has experienced a problem...to test, this sequence is needed:
The results of this will indicate if it's your BB or your battery that has the problem. If it turns out to be the BB, then your nest step is in-hand evaluation by a qualified technician -- or just replacement.
Good luck and let us know!