I think you should get rid of it. And I just happen to be a self appointed Bernina Record Disposal agent. I'll even pay the shipping from your house to mine.
I love my 830. And how often do you zigzag in quilting anyway? If it goes forward and reverse, 98% of your sewing is taken care of.
Anyhow, that machine is a truck. Take it in when you can and get it troubleshot. In the mean time, use it. Beautiful machine. tim in san jose