Haier HPU-42CV03 Service Manual page 50

2) Sensor failure
check if the wiring is
correct according to
wiring diagram
if sensor is fixed
well
yes
Is sensor short-circuit
or open-circuit?
yes
Is sensor resistance
acceptable?
yes
Is DC voltage between
both ends of sensor
near 5V or 0V?
no
Replace PCB
3) EEPROM failure
start
Is EEPROM in mainboard
inversely connected or in
poor contact?
replace EEPROM
Power on again to
check if failure is
eliminated
Commercial Air Conditioner
no
reconnect
no
Relocate
yes
Replace sensor
no
Replace sensor
no
re-set
no
replace PCB
49
Model: HPU-42CV03
HPU-42HV03