BERNINA's are very good machines, find a local dealer and take it in, chances are it is ( operator error) and something simple. Do you have the manual? Sometimes it is simply an error in threading, some lint under the bobbin case, the need of a new needle or a change in thread. Have the machine serviced and ask about an ( owners class- which are often free) to learn the bells & whistles- the machine will probably give you many years of great service once you learn it