Troubleshooting by Indication on the Remote Controller
Mini UM S/M
148
Troubleshooting
4.38
“
U4
”
Malfunction of Transmission between Indoor Units
and Outdoor Units
Remote
Controller
Display
U4
Applicable
Models
AII indoor unit models
AII outdoor unit models
Method of
Malfunction
Detection
Microcomputer checks if transmission between indoor and outdoor units is normal.
Malfunction
Decision
Conditions
When transmission is not carried out normally for a certain amount of time
Supposed
Causes
Indoor to outdoor, outdoor to outdoor transmission wiring F1, F2 disconnection, short circuit
or wrong wiring
Outdoor unit power supply is OFF
System address doesn’t match
Defect of outdoor unit PC board
Defect of indoor unit PC board
Mini UM.book Page 148 Monday, January 24, 2005 11:32 AM