I may have an answer for you. Years ago about 25 or so I bought a high end singer. It did nothing but give me trouble and have and will never buy another singer...anyway I tried everything just as you are doing and someone told me that Good Housekeeping had a warranty on Singers and they stand by that. I contacted Good Housekeeping and within the week my problem was solved. Magazines in today's world are not like yesteryear...but it is worth a shot...Good luck.