I have a 1995 Craftsman chain drive garage door opener that is no longer operating correctly. When trying to lower the door, the motor starts and the door moves a couple of inches down, the motor then stops, and the light blinks several times. I have a feeling it has to do with a malfunction of the Safety mechanism that prevents the door to close if it encounters resistance. No resistance exists though. When disconnected, the door moves very smoothly. I have bypassed the wall switch and the electric eye sensors with the same results. The remote openers have the same problem. Any ideas on what to try next, what the problem might be, what to do to fix the problem myself, and does Sears sell parts if it needs a part.
Thank you in advance for any expertise anyone can share.