395655034161. Remove power from operator.2. Press down on tabs to remove lens.3. Remove light bulbs.4. Note locations and remove BWC (Basic Wall Control) and STB (Safe-T-Beam ®) wires. Use small screwdriver to press in on orangetabs to remove wires. FIG. 1.5. If equipped, unplug and remove battery backup (BBU) from back of motor housing. Fig. 2.CLOSE DOOR PRIOR TO REPAIR.PARTS REMOVED FOR CLARITY09/2016Scan code or visithttp://www.openerserviceassistant.com/39272S.S & 39272T.S .htmto view a video of this repair.24V DC Opto ReplacementFor Chain & Belt OperatorsWARNINGBE SURE ELECTRICAL POWER HAS BEEN DISCONNECTED FROM THE OPENER PRIOR TO REMOVING THE MOTOR COVER.!WARNINGANY AND ALL REPAIRS MADE TO THIS UNIT MUST BE PERFORMED WITH THE DOOR DISCONNECTED FROM THE OPENER AND IN THECLOSED POSITION.!These instructions are written assuming that you will have ample room around Opener to perform this repair. Some rare instanceswill require removal of the unit from it’s mounting hardware and repair made on a bench or floor. Refer to your Owners Manual orInstallation Poster for proper assembly and carefully read and understand all warnings and cautions pertaining to your unit.Tools required: Standard slotted and Phillips head screwdrivers, small slotted screwdriver, 5/16” nutdriver.FIG. 1FIG. 239272S.S 39272T.S