One bulb not working

I’ve searched all over without any answers please help.

I have 1ac150-2m craftsman garage door opener. One bulb doesn’t work, Here are my troubleshooting steps taken with no results.

  1. Replace bulb with working bulb
  2. Swapped Sockets from one side to the other.
  3. Checked Electrical wiring with electric tester works. fine

Board is working fine hence the other side bulb works and I hear the clicking sound.

The only thing i haven’t tried which may be my last result is check the lighting wiring any help would be greatly appreciated.