SMEG Dishwasher Type 12053, DI 612C has stopped working…

Our dishwasher has decided it has had enough.

The problem started where it would complete most of the cycle and then beep plaintively at us – and make random noises. Moving it on to a different cycle would drain the water and that would be sufficient. Now, it won’t even start a cycle (we’ve tried ’em all – ECO, normal, pans, glasses, etc) – just churns a bit and beeps like R2-D2.

Have cleaned all the filters etc, but this hasn’t helped. Anyone have any idea what might have gone wrong?

It’s a Smeg built-in job – type and model number as above, so I’ve a horrible feeling that it’ll cost an arm and a leg to put right.

Any advice gratefully received…