BOSCH ahs7000pro no pwer!?

Hi
I used my Bosch ahs7000pro at the end of Summer 2010 or was well,I got it out today for the 1st cut of the new season,I pluged it in+no power,I replaced the fuse with a new one,I tried using a diffrent socket,+Finaly I tried a secound extention Lead,All these failes,I have not unscrewed the star screws,Has anybody had this same problem?I could do with some help Please.
ATB
Ceri