To correct this problem, put the presser foot up and unthread the sewing machine entirely. Rethread the machine with the presser foot up. Follow your sewing machine manual to make sure you are guiding the thread through all of the guides in the proper fashion. One of the most common mistakes people make is to thread a sewing machine with the presser foot down. This causes the tension disks to be engaged or tight, preventing the thread from seating properly between the disks. Skipped stitches can also result if the needle is bent, which can occur if you are forcing the fabric, rather than let the machine feed it automatically. A sewing machine needle is the smallest and usually one of the least expensive parts of a sewing machine to replace; you owe it to yourself to understand everything about sewing machine needles. If there is no such setting on your machine, take off the throat plate and clean out all dust, thread, and lint. Oil the machine according to your sewing machine manual. If the feed dogs still do not work, troubleshoot the problem with your sewing machine manual. When all else fails, it may be time to take the machine in for repairs. Before you start sewing again, check your sewing machine needle. Even a slightly bent needle can cause a thread jam.
Is the thread getting hung up on the thread spool itself? This could be caused by a nick at the end of the spool or a notch in the spool (designed to secure the end of the thread). You can eliminate the problem by changing the direction the thread feeds off of the spool. Are you using old or low-quality thread? Have a look at what kind of thread you are using, and discard supplies that seem old or of poor quality. Are you using a relatively new sewing machine needle? If the needle has sewn over pins, it may have a nick in it that will play havoc with the thread, causing it to break and shred. There are specialty needles that have a larger path for special threads.
If the thread continues to break after you have checked out these possibilities, thoroughly clean out all dust and lint from the bobbin area and the tension disks. Run your fingers over the path traveled by the thread, looking for any kind of burr, debris, or loose fabric that could cause snags.
