Sears or Lift Master garage opener board fix.
After scanning the forums I could not find a fix to my problem, so I went after it myself and this is what I found. My 1993 1/2 hp Lift Master with PC board #41A4252-7 Model 1255 was intermitantly not going down when open. I check all the stuff suggested by the forum and all check OK. Then I pulled the PC board out and found the connection on the PC board from the big Relay was just barely visiable but was cracked away from its solder joint. Resoldered and now it works great. This board is used in alot of openers if yours is acting up and you hear a clicking but the motor does not start you might want to look at this.