LiftMaster JDC Installation Manual - English French Spanish - Page 61

Troubleshooting (continued) Code Display Message F102 F102 BBU DISCONN Description Possible Causes Diagnosis Resolution Battery is learned to the system but the battery is not detected Backup battery is disconnected Verify all battery wiring is connected securely and properly to the correct terminals and with the correct polarity. Correct any wiring issues. Battery is worn Batteries can be tested out or has failed with a suitable battery tester. Older batteries are more likely to be worn out, as are batteries that are used often. Replace batteries. Always replace both batteries as a set. Do not mix old and new batteries or use mismatched types. Battery fuses blown Visually inspect battery fuses or measure the fuses with a multimeter for continuity. If fuses are blown, replace both together with new fuses. F105 F105 AC FAIL AC failure. System is running on battery. Power outage Input voltage outside specifications Check for proper voltage Error code will resolve when at the input of the power is restored operator Check for proper voltage Ensure voltage supplied to the at the input of the operator is within the specified operator operating range F106 F106 WC SHORT Indicates wall control is removed and jumpered out. Wall control is intentionally disconnected Wiring short circuit Error message is informational only. Inspect wiring for short circuits, damage, etc. Liftmaster strongly recommends using the provided LCD wall control with the operator. Resolve any faults found, then power cycle the operator Damaged wall control Replace wall control with If known good wall control known-good unit, then resolves the issue, replace the power cycle the operator bad wall control F120 F120 MAINT DUE Maintenance counter reached preset limit Maintenance counter reached preset limit F120 error code Reset maintenance counter using the menu through the wall control F121 F121 OVER CYCLED Standard/ extended cycle count reached Operator has Refer to specified cycle been cycled too ratings for the operator many times in a model that is installed short period of time Reduce cycle rate to ensure it is within specifications for the operator 61