We have a brother ES-2010 computer. When using it one day for something that was inevitably too thick it made a nasty noise and snapped the needle. It then wouldn't work properly. I dismantled the area underneath the needle and found that the rotary hook had a small chip out of the back. I removed the fragment and reassembled. Since then it works fine most of the time but will suddenly jam and snap a needle. I can't see that the chip in the rotary hook will do anything but from looking I can replace that part. I just wanted to check if anyone had any other ideas to try before replacing parts?
