Mine has the same problem, motor runs but chain doesn't move. The chain break / hand guard is in the correct position.
Dave Evans, January 2015
They have a safety break - it disengages motor from chain - a big shield between your hand and the blade - back towards you = chain engaged - pushed forward disengaged.
https://www.youtube.com/watch?v=Do5DfkHBhtg
L Jack, October 2014
edit
I can answer this question...
Chain does not rotate even though motor is running?
