Check the printed circuit board which is underneath the dash in a blackbox above the fueltank, there are two 10amp glass fuses one of which controls the cutting deck if it's blown that's your problem or if there are blown resistors that's also an issue which i'm having just now! You can get the glass fuses from your local electrical repair shop they are used in microwaves but they won't give you them as it's not advised you repair your own microwave, just tell them it's for a ride on lawnmower and you should be fine.
David Rankin, October 2010
