Toshiba HFC R407C Service Manual page 51

Diagnostic procedure for check code
Check code
[8A]
Multi Controller PC board malfunction
Check lead connection between indoor unit and Multi Controller and outdoor unit.
If no error is detected, replace Multi Controller board (MCC-1210).
Check code
[97]
Central management communication
short circuit
Are X,Y communication cables
normal?
Yes
Is there a connection error of
power source wiring?
No
Is the power source 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
different from main or sub
remote controller?
Yes
Clear the alarm after turning on
the power source, and start the
operation.
Troubleshooting
No
Yes
No
Yes
Is the operation status of
No
the indoor unit reflected on
the central controller?
Yes
No
Is there noise
interference, etc.?
No
Central controller error
Operation cause
1. Multi Controller PC board error.
Operation cause
1. Connection error of (XY) for outdoor units.
2. Power source system error of the central
controller and indoor unit.
3. Noise of peripheral devices.
4. Power failure.
5. Indoor PC board error, central controller error.
Clear the alarm after turning on the
power source, and start the operation.
No
Yes
Check communication cable.
Check power source wiring.
Indoor PC board error
No
Is there noise
interference, etc.?
Yes
Eliminate noise interference.
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