garage door opener problem
Hello to anyone who can help, I saw a posting with similar problem as mine regarding the craftsman garage door opener. It closes but goes back up automatically only about 20 inches and stops there, tried few times, still the same. But now since my brother tried adjusting the up and down force options (turning the adjustment trying to see if it'll help lift the door up any higher), the door now wouldn't even open. The motor hums for few seconds, then stops. So now I know is probably the spring, I wish I have seen posting mentioning the spring being the problem earlier, before getting my brother do any adjusting, now I don't know if there is any more damage,since it now won't open other then motor humming.
Anyway,where can one buy the spring, and what is the cost approx.? Where is the position of the spring, I have the manual, but could NOT find anywhere saying there's a spring. Please help me asap if u can, I don't want to buy a new opener if I don't have to., Thankyou