Sewing Machine Problem. I have a 830 Bernina Sewing machine and none of the zig zag stitches will

Question

I have a 830 Bernina Sewing machine and none of the zig zag stitches will work, blind hem, ect. Have any idea what the problem might be? I've had this machine for years and have never had any problems with it until now.
I would appreciate any help you might have.

Thank you,
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