I read a few of your reviews and found that a, "Phase Control Board" may be the problem. It was! Talk about easy to install... It was super easy! I decided to order the, "Speed Control Plate" also as a precaution (Shipping was one price - and it arrived the very next day, Wow! I didn't expect that.) With my screwdriver and good lighting. I fixed it myself! My husband is still in shock. I used forceps to install the, "Speed Control Plate," because I needed something to hold the tension wire - at the bottom. I noticed the center of my old control plate was worn through. Everything works great! Youtube has wonderful videos to help.
Thank you again, Alice F. Kansas