innovair ICS0629C21, Service Manual

Page: 78 / 103

2.4 Solving steps for typical malfunction
2.4.1 For the indoor unit
2.4.1.1 Open or short circuit of temperature sensor
Check the connections
between temperature
sensor and PCB. Are the
connections good?
Check the connections
between temperature
sensor and PCB. Are the
connections good?
Correct the connections.
Correct the connections. No
Yes
No
Replace the sensor.
Replace the sensor.
Replace the indoor PCB
Replace the indoor PCB
Measure the resistance value
of the sensor via Appendix 1
Measure the resistance value
of the sensor via Appendix 1
Is it normal?
Is it normal?
Yes
2.4.1.2. Outdoor unit malfunction
Whether the outdoor
main board has error
displayed
Whether the outdoor
main board has error
displayed
Power off, then restart the unit 2
minutes later. If the outdoor main board
displays error code several minutes
later?
Power off, then restart the unit 2
minutes later. If the outdoor main board
displays error code several minutes
later?
No
Yes
Refer to corresponding
solving steps
Refer to corresponding
solving steps
Yes
2.4.1.3. Indoor EEPROM malfunction
Yes
Replace the indoor main PCB
Power off, then restart the
unit 2 minutes later
EEPROM: An electrically erasable programmable read-only memory whose contents can be erased and
reprogrammed using a pulsed voltage.
74 Electrical Control System