Originally Posted by emmah

One more thing to check...there might be a little burr of metal on the needle plate above or below the hole the needle goes down thru, usually caused by a needle hitting the hole side. It is hard to see, but will snag and cause thread breakage. Only way to check for it is by feel, be careful as it can cut your finger--found out the hard way! I used an emery board to smooth away the burr.