Patty sanders

There is nobody in my area that services the phaff sewing machine. Can you tell me what tension you use for top quilting please. I’ve had the machine for about three years and it was preowned. Everything started working just fine and then all of a sudden I can’t get the tension right. I have bought king tut thread in superior and it just seems like it just doesn’t want to take any thread now it breaks thread off within 3 inches of quilting. I would appreciate any Suggestions you can offer.