Mitsubishi Electric MXZ-SM72TAM-U1 Service Manual page 88

8-3-2. For MA remote controller systems
Symptom or inspection code
Though the content of operation is displayed on the re-
mote controller, some indoor units do not operate.
Though the indoor unit operates, the display of the remote
controller goes out soon.
The display of the remote controller does not come up.
"Please Wait" keeps being displayed or it is displayed peri-
odically.
("Please Wait" is usually displayed for 3 minutes after the
power supply of the outdoor unit is on.)
The remote controller does not operate.
Inspection method and solution
• Check the part where the abnormality occurs.
1. The entire system
2. In the entire refrigerant system
3. In the same group only
4. 1 indoor unit only
OCH800A_88
Cause
• The power supply of the indoor unit is not on.
• Wiring between indoor units in the same group is not
finished.
• M-IC and A-IC are connected in the same group.
• The fuse on the indoor unit controller board is blown.
• The power supply of the indoor unit (Main) is not on.
• In the case of connecting the system controller, the
setting of the system controller does not correspond to
that of MA remote controller.
• The fuse on the indoor unit (Main) controller board is
blown.
The remote controller is not fed until the power supply of
both indoor unit and outdoor unit is on and the startup of
both units is finished normally.
• The power supply of the indoor unit is not on.
• The power supply of the outdoor unit is not on.
• The number of connected remote controllers is over the
limit (Maximum: 2 units) or the number of connected
indoor units is over the limit (Maximum: 16 units).
• The address of the indoor unit is "00" and the address
for the outdoor unit is the one other than "00".
• The transmission line of the indoor/outdoor unit is con-
nected to TB15.
• MA remote controller is connected to the transmission
line of the indoor/outdoor unit.
• The remote controller cable is shorted or down.
• The power supply cable or the transmission line is
shorted or down.
• The fuse on the indoor unit controller board is blown.
• The power supply of the outdoor unit is not on.
• The power supply of the feeding expansion unit for the
transmission line is not on.
• The setting of MA remote controller is not main remote
controller, but sub-remote controller.
• MA remote controller is connected to the transmission
line of the indoor/outdoor unit.
• The power supply of the indoor unit (Main) is not on.
• The transmission line of the indoor/outdoor unit is con-
nected to TB15.
• The transmission line of the indoor/outdoor unit is short-
ed, down or badly contacted.
• The fuse on the indoor unit controller board is blown.
In the case of the entire system or in the entire refrigerant
system
• Check the self-diagnosis LED of the outdoor unit.
• Check the items shown in the left that are related to the
outdoor unit.
In the case of in the same group only or 1 indoor unit only
• Check the items shown in the left that are related to the
indoor unit.