On Jun 19, 2020, at 6:51 PM, Jim Stutsman via groups.io <onlinesewing@...> wrote:

The bobbin case was not the only thing damaged. More than likely the needle hit the hook race, which is the aluminum "basket" that the bobbin case sits on. That would cause it to be noisy. Worse, though, is that a nick, gouge, or other damage to the hook race will catch thread while sewing and not allow it to release once it's made the trip around the bobbin case. When the stitch doesn't release it will quickly cause other stitches to pile up and force the bobbin case up past the stopper, causing what you saw. You can examine the hook race yourself with a strong light and magnifying glass. Look for anything that is not perfectly smooth. Also check the bobbin case stopper. It may be damaged or out of position, so it allows the bobbin case to pop up easily. If there is damage you'll need to see your dealer again. Janome has a tool for buffing hook race damage, part #OILSTONE.