How to fix Belle Minimix 150 which just hums?

Little used Minimix 150 240v bought new 2002ish did 2 mixes yesterday but refused to start for third mix. When I press the green button I just get a humming noise. The drum will not rotate by hand. If I manually rotate the pulley the drum does turn. Mixer had not been used for 3 years: I forgot at least 2 rules: I put the mix in b4 starting motor & emptied with it stopped. Does this sound terminal or is it obvious to those with normal brain cell levels what needs fixing? many thanks. Model No 234709M16A made 2001

Derek42
June 2010