if my main fuse trip you mean an RCD (this will generally be a double width trip switch with a button on it marked test or T this would indicate an earth leakage problem with your fridge. if this is the case the general diagnosis would be that the compressor has failed and the fridge is beyond repair.
if you are lucky it may just be moisture has got into the electrical connections or the main power flex is damaged.
good luck
sparky
September 2008