Toshiba MMU-P0121H Service Manual page 77

<For 4-way Air Discharge Cassette type>
Check code
[97]
BUS communication alarm (1)
Are X, Y and P, Q
communication cables normal?
YES
Is connection of CN602
connector on interface
P.C. board of the master
outdoor unit normal?
YES
Is there no connection error
of power supply wiring?
NO
Is the power supply
of either central controller or
indoor/outdoor turned on?
YES
Did power failure occur?
NO
Is [97] displayed only
on the central controller?
YES
Is the network address
difficult from main or
sub remote controller?
YES
Clear the alarm after turning
on the power supply, and
start the operation.
1. Connection error of communication cable (PQ) between indoor
and outdoor
2. Connection error of (XY) for outdoor or indoor communication
3. Power supply system error of the central controller and indoor
4. Noise of peripheral devices
5. Power failure
6. Failure of indoor main P.C. board (MCC-1361) or central
controller
NO
NO
YES
NO
YES
Is the operation status
NO
of the indoor unit reflected on
the central controller?
YES
NO
Is there no noise source, etc.?
NO
Indoor main P.C. board
(MCC-1361) failure
3-74
Operation cause
Modify communication cable.
Modify connection of connector.
Modify power supply wiring.
Clear the alarm after turning
on the power supply, and
start the operation.
NO
Indoor main P.C. board
(MCC-1361) failure
Is there no noise source, etc.?
YES
Eliminate noise.
NO
YES