don, I don't know if the Craftsman are the same as my Chamberlin belt drives or if it would be related at all....Someone hit an electrical transformer and my power surged on and off about 3 times in rapid succession. All of my remotes had to be reprogrammed, including the wireless ones mounted on the outside. I again had the same issue once again when lightning struck nearby. Would those surges have cleared the memory?

Multiple weak digital signals on the same frequency in close proximity to each other can result in none of them working.

My suggestion is you trade a few bucks for a fast upgrade that takes the old remote out of the picture. You can buy a new receiver at most home centers that has all the high security feature, comes with one or two remotes, and will work with the transmitters built into many newer vehicles. You wire it into the old power head as if it were a wall button. It's neat, easy, secure, and fairly cheap. Worth considering provided the power head is in good shape. Since it just wires in like the wall switch, any brand will work. One example is Chamberlain Universal Radio Control Replacement Kit, $57 at Lowes. Note: Safety regs get stricter all the time. Newer units may have less range by design, but still work.

Sorry, Don, but I'm a little confused. Both little green lights on the two sensors mounted on 2 rails near garage floor are lit green, and seem to work, reversing decending door when the site line is broken. When door is coming down, but I then block the sensors, door goes back up and main light flashes 10 times. But I cannot get my remote to close the door even when there is NO blockage. So do you think I need new sensors or new sensor wiring, as was also suggested to me? But not a new receiver board? (I assume if the remote will always open the door, then the battery in it is still good, right?)