Mitsubishi Electric · MSZ-AY Air Conditioners
The indoor unit's upper lamp blinks three times, indicating that the rotational frequency feedback signal is not being emitted during indoor fan operation. This suggests a problem with the indoor fan motor.
Click steps to track your progress.
Refer to 'Check of indoor fan motor' section (10-6) in the full manual.
Turn OFF the power supply to the unit at the circuit breaker and wait a few minutes before turning it back on.
If the error persists, a qualified technician should inspect the indoor fan motor and its connections.