I have a JG MP5SD6 and it won't shoot what now?

I have a JG MP5 SD6 and just before I was shooting it and it was just fine i shot it in short bursts for a little while and when the battery finally did run out I charged it and when it was fully charged. Then I shoot the gun and nothing happened...WTF what do I do???? Is it the motor, gearbox (highly doubt) or did the battery short out?