Janome 6600 tension. The tension dial is not working and the thread going through it is loose. The

Question

The tension dial is not working and the thread going through it is loose. The dial goes all the way up to 9 and is barely acceptable for general sewing but not for something I want to be done well. I did not notice why or when this happened and the machine probable has about 15 sewing hours on it since bought brand new.