LiftMaster 8550 8550 Manual - Page 35

Troubleshooting Diagnostic Chart Your garage door opener is programmed with self-diagnostic capabilities. The UP and DOWN arrows on the garage door opener flash the diagnostic codes. DIAGNOSTIC UP CODE ARROW DOWN ARROW SYMPTOM CAUSE RESOLUTION 1-1 1 FLASH 1 FLASH The garage door opener will not close Safety sensors are not Inspect sensor wires for a disconnected or cut wire(s). If the sending sensor with the and the light(s) will flash installed, connected, or amber LED is NOT lit, check the wire and connections for that sensor. If sending wires may be cut sensor LED is lit, check the wire connections leading to the receiving sensor (green LED). Reattach wire or replace wire (22 gauge wire) as needed. If pre-wired home, check the splices. See page 18 for installation. Close the garage door using the remote control or the door control. The garage door opener will not close Safety sensor wire Inspect sensor wire for incorrect wiring or a pinched wire. If the sending sensor and the light(s) will flash shorted or reversed (amber LED) is not lit, check the wire leading to and from that sensor. Check staple 1-2 1 FLASH 2 FLASHES points. If sending sensor LED is lit, check the wire leading to the receiving sensor (green LED). Reattach wire or replace wire (22 gauge wire) as needed. If pre-wired home, check the splices. See page 18 for installation. Close the garage door using the remote control or the door control. Wall-mounted door control will not The wires for the door Inspect door control wires for a short (staple in wire), replace wire (22 gauge wire) as 1-3 1 FLASH 3 FLASHES function control are shorted or needed. After installing new door control wires, if door control still does not operate the door control is faulty garage door opener, replace the door control. The garage door opener will not close Misaligned or Realign the receiving sensor (green LED) by ensuring the LED is steady and not 1-4 1 FLASH 4 FLASHES the door and the light(s) flash obstructed safety sensors flickering. A flicker of the safety sensor LED indicates a misalignment. Make sure nothing is hanging or mounted on the door interrupting the sensor's path while closing. Close the garage door using the remote control or the door control. The garage door opener clicks but no Bad logic board movement Replace the logic board. 1-5 1 FLASH 5 FLASHES The opener runs approximately 6-8" Communication error to Disconnect all power, remove cover, and locate the travel module. Ensure the wires and stops and/or reverses travel module for travel module are connected, if wires are connected, then replace the travel module. 35