When I took my repaired Bernina home and had the same problem again, the RM said it was because the machine tipped over in the trunk of my car on the way home. Can't figure how it righted itself by the time I got home. Told him not to insult me and ask for the owner who happened to be a longtime friend. He was gone in a month.
I have a dealer-RM that also takes a long time but that's because he's very good and reliable and has customers around the block. He does have trouble getting some parts especially on older machines. He has no control over that. We who go to him have the solution. We call ahead to see how long it will be and we all have backup machines. Wouldn't be without mine.