Not familiar but looked seems to be a pruner bayonet saw which therefore has a flex drive much llke the drive on old car speedometers.
Could be what you are hearing is the motor going but the drive to blade has broken.
Contact www.flymo.com use their online form. My guess is a problem with the drive to the blade as the noise sounds like the motor is running but drive to blade faulty.
bob
May 2012
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