Toshiba MMU-P0121H Service Manual page 89

Check code
[cF]
Communication alarm between
indoor MCU
Check disconnection of lead wire and connection of connector between indoor main P.C. board (MCC-1361)
and indoor motor P.C. board (MCC-1382).
If no error is detected, replace indoor main P.C. board (MCC-1361) or indoor motor P.C. board (MCC-1382).
Check code
[d1]
Master outdoor unit set up alarm
Are multiple inverter
outdoor units connected?
NO
Is set up of the master outdoor
units at center position duplicated?
Set SW08 bit 2 on interface
[
P.C. board of each unit. (*1)
NO
Check interface P.C. board.
( * 1) Set up of outdoor unit at center position (SW08 bit 2 set up on outdoor interface P.C. board)
OFF : Server/ON : Master (Automatic set up for inverter outdoor unit)
1. Error of connection between CN28 of indoor main P.C. board
(MCC-1361) and CN27 of indoor motor P.C. board (MCC-1382)
2. Indoor main P.C. board (MCC-1361) error
3. Indoor motor P.C. board (MCC-1382) error
1. No. of connected inverter outdoor units
2. Incorrect set up of master outdoor unit
3. Defective outdoor interface P.C. board
YES
YES
]
3-86
Operation cause
Operation cause
Set only one inverter
outdoor unit for 1 system.
Set only one unit as master,
turn off all power supply ,
and then restart the operation.