Toshiba MMU-P0121H Service Manual page 86

Check code
[b5]
Indoor outside input alarm
[b6]
Indoor outside interlock
Is outside device connected
to connector CN21 of indoor main
P.C. board (MCC-1361)?
YES
Is outside device connected
YES
Check cause of the operation.
Check code
[b7]
Secondly unit alarm in group
operating
When a trouble occurred on any one of the secondly units operating in a group, an alarm is output to the
central control remote controller.
Using the remote controller of indoor unit, check a trouble on each secondly unit and take measures against
the error code.
Check code
[b9]
Indoor pressure sensor alarm
There is an abnormal output voltage of indoor pressure sensor. Check disconnection of connector (CN23) of
indoor main P.C. board (MCC-1361) and output voltage of the sensor.
If the sensor is normal, replace the indoor main P.C. board. (MCC-1361)
1. External device error
2. Indoor main P.C. board (MCC-1361) error
NO
NO
Secondly unit error at group operating of the indoor unit
Output voltage error of indoor pressure sensor
3-83
Operation cause
Check indoor main
P.C. board. (MCC-1361)
Defective Replacement
Check outside device.
Defective Replacement
Operation cause
Operation cause