I have sears garage door opener, the door only does down. took the chain off and it never stops downward movement. the contacts to stop it seem OK, no loose wires
What is model number and how old is opener?
model 139.53673srt1. I didn't write down when we installed it but I think it's about 8 years old
check the brown wire on the down contact on the limit switch assembly, it may be loose. Otherwise the contact may be slightly off.
Actually your opener is about 14 years old, I am going with the manual that I have for this opener,