Hate when that happens! It is so frustrating when you are ready to sew and the machine isn't! I do not have that machine, but the other day I hand wound a bobbin, tried to put it in the case and it would not go. Looked at both sides of the bobbin, they looked the same. Unwound the bobbin, wound it the other way and it went in. Evidently, some bobbins have a right and wrong side. Could that be the problem? Or, try another bobbin, just for kicks.... Does it have a metal bobbin? A few weeks ago someone had a discussion on bobbins, and somehow, her's had gotten warped and caused all kinds of problems. Hope you can find out the problem without having to take it to the Dr.