Toshiba MM-A0280HT Service Manual page 71

BUS communication alarm (1)
Are X,Y and PQ
communication cables normal?
Is connection of CN101 on
the indoor P .C. board normal?
(When indoor PQ communication
cable is connected.)
Is connection of CN602
on interface P .C. board
of the master outdoor
Is there a connection error
of power source wiring?
Is the source power
of either central controller or
indoor/outdoor turned on?
14
Did power failure occur?
Is [97] displayed only
on the central controller?
Is the network address
different from main or sub
remote controller?
Clear the alarm after turning
on the power source, and
start the operation.
Troubleshooting
Diagnostic Procedure for Check Code
Check code
[97]
No
Yes
No
Yes
No
unit normal?
Yes
Yes
No
No
Yes
Yes
No
No
Yes
No
Yes
1. Connection error of communication cable (PQ)
between indoor and outdoor units
2. Connection error of (XY) for outdoor units
3. Power source system error of the central controller
and indoor unit
4. Noise of peripheral devices
5. Power failure
6. Indoor P .C. board error, central controller error
Is the operation status
of the indoor unit reflected on
the central controller?
Yes
Is there noise interference, etc.?
No
Central controller error
72
Operation cause
Check communication cable.
Check connector connection.
Check connector connection.
Check power source wiring.
Clear the alarm after turning
on the power source, and
start the operation.
No
Indoor P .C. board error
No
Is there noise interference, etc.?
Yes
Yes
Eliminate noise interference.