Well my embroidery machine is home. It sewed out a design at the shop beautifully. I have been finishing a shirt for DH today so will only use my embroidery machine tomorrow. I was only charged a very small amount. I think I know what could have happened. I broke two needles at the time my machine was making a grating sound. I only found the point of one. I am sure the other point got caught somewhere in the bobbin housing. The journey to the technician probably loosened it and that is why he could not find any fault.