I was recently given a Singer 756 & I'm trying to learn the features that my old machine didn't have. I was trying out the Feather stitch, & all my settings are correct according to the Users Manual, but my threads keep breaking. Sometimes it's the upper & other times the bobbin thread. I sewed just fine yesterday w/ a straight stitch. If there is a troubleshooting guide in the manual, I have overlooked it at least a dozen times. Please tell me what I can do myself b/c I can't pay anything. I don't see anything about fees, so I pray there are none.