Do I need professional to refit a power or refridgeration unit?

My Scandinova upright freezer has just packed in. The power/tempreture indicator has been flashing for a few days and now it has just shut down. Can I repair this - i.e., install a new power and/or refidgeration unit - myself or is it something that only a professional can do? Also any thoughts on what has gone wrong?

Chris Parrott
April 2007