If the machine trips the breaker you can either call an appliance engineer or attempt diagnosis yourself - probable points of failure are likely to be:
The heating element - try disconnecting it and running a test programme
The water inlet solenoid - it the trip happens at filling time then Bingo!
The detergent flap solenoid - try disconnecting it and running a programme
The main pump - try disconnecting it and running a programme
There's a small possibility that the electronic control unit (or more probably the power supply to it) is faulty but if you get any signs that it's OK - like lights being on and things happening - then it's very likely nothing to do with the fault - the last thing to suspect.
Good luck...
Peccavi, November 2009