I would really suggest that if you can take this into the dealer that you bought this from they would probably service this for you AND help you find out what the problem is with it.
I know that a good relationship with a dealer is crucial!! I had a much beloved Pfaff that I got when I started to sew a few years ago. I traded it up a couple of times until I got one that does embroidery. When it came time to use it for that my dealer didn't know how to do that which left me in the dark. Needless to say I went on to find another dealer and brand. I got a Janome and "married" the new dealer. I upgraded within a 6 week time (I just had to have the big one NOW
) till I got the top of the line with all of the bells and whistles, but they hold my hand if needed. Heck they came to the house to set me up. I can come into the store anytime I need help and I can get it. I have spent as much as 3 hours at a time with the Janome person. Now I don't do that often but I know that it is there if I need it.
suggest that you find a good dealer and buy from them instead of a box store if you need to get rid of what you have. But I don't think you will. It sounds like you just need a service... Sorry to ramble.