Hmm, a reset won't effect the battery not powering.
1. Try pulling the battery out and then after a few minutes putting it back in and then try charging it. (if this is a device that makes it hard to pull a battery, then make sure you are not under warranty before doing it).
2. Try a different charger cord. They go all the time, so try one from a different device and see if that works.
3. If it still won't charge, after trying 1 and 2, then you may need a new battery.
4. NOTE: If it is under warranty, contact the manufacturer about a repair or replacement.