I had the some problem and sent it in to be worked on twice. when a man I was looking at buying a new machine from told me to try putting in a new needle and them bring it down just the space of a paper clip before you tighten up your needle. IT WORKED!!! I have not had a problem scene. He said the Janome1600P has a problem with the shaft bending and this will help. Hope this helps with your problem.