Craftsman garage door opener problems
I am having trouble with my 3 year old Craftsman garage door opener, 3/4HP model 139.53990D. The door will open about a foot and then quits. I believe the obstruction sensors are working properly and there is no obstruction. The light sensors work and stop the door if there is an obstruction. I manually assisted the auto opener and the door will open to normal height. It will come down properly but only open a foot. This opener has built in diagnostics and no errors have been detected. The garage door is a nine year old Wayne Dalton sectional with the Torquemaster spring system. I checked and the springs are not broken and are set to mfg. specs for tension. Help?