The hand wheel is stiff to turn after not being used for one year; I think the belt might need replacing tho I had the machine serviced just over a year ago. I don't know how to access the belt in order to try to adjust or replace it.
Hello Victoria,
You should be able to unscrew the top on that model and take the end panel off, before you do that take out the bobbin case and raceway and clean it an put a few drops of oil in there, you may find it is stuck.
Ken