I have repaired a number of Bernina 930 circuit boards (in the UK) There is a common fault. It seems Bernina fitted one component of poor quality which blows after some time.. probably most machines will suffer this - in time.
When this component blows, specific 'capacitors' and other adjacent components commonly fail (UK 230V machines) causing the machine to be 'dead'
Do Not Despair. Find an electronic engineer who cares enough to spend time on the PCB. You don't necessarily need a sewing machine expert.
Is this fault common on 115V machines in the USA???
I agree with Mickey2. The 930 is the last of the Rolls Royce mechanical machines. Beautiful, quiet, strong etc