There's two circuit boards on your Bernina. The L-print is the power board. The S-print is the brains. Sounds like they probably should have replaced the S-print. Those are a lot more expensive, and they probably wanted to try the less expensive route first. The S-print is $273 retail just for the part. There's a 5 year warranty on the circuit boards. The updated parts do have a better life than the ones they put in 9 years ago.
We're seeing a lot of 230s with power board failures. The common occurrence is that they all have been turned off for a long time -- 6 months to 3 years without being sewn on.