If I retry it may start but sometimes not. If I wait this helps. Sometimes if I get a fully charged battery (I have 2) it works. But this may be due to the additional waiting time when I go to get the battery. The blade turns freely and there are no unusual vibrations. Nothing seems unusually hot. As a result of all of this, the batteries never run down all the way any more. Instead it reaches a point where I can't re-engage the motor because the light keeps going yellow. So far going and gettng a fully charged battery seems to get it oer the hump, but I fear something is definitely going wrong.