Quiltingboard Forums - Brother NX600

I have this machine (for classes only) and it's ready for the junk pile as I am not willing to spend more $ on it. I have replaced feed dogs, throat plate & bobbin casing. Still doesn't work, seems like feed dogs just don't move the fabric. Works as if the foot is too close to the feed dogs & just grinds the fabric (I know clear as mud). Can't really explain, it's kinda like the foot & feed dogs have a life & death grip on the fabric. If I tug a little hard on the fabric from the back it will sew but it really doesn't want too. I really want to get another machine or quilt classes (insert big groan). The repair guy now thinks it might be a worn gear. He's 80 miles away, so not wanting to go there to be told he can't repair it( and he probably can't). Is there anything I can do (orDH), he's pretty handy.