Haier HSU18VHJ(DB) Service Manual page 69

7.3.9 Power Supply Over or under voltagve fault
Indoor display
outdoor display:
Method of An abnormal voltage rise or fall is detected by checking the specified voltage detection
circuit.
Malfunction
Detection
Malfunction An voltage signal is fed from the voltage detection circuit to the microcomputer
Decision
Conditions
Supposed
Causes the IPM module is broken
the outdoor PCB is broken
T roubleshooting * Caution Be sure to turn off power switch before connect or disconnect connector,
Check the power supply
Is it rated power?
Yes
Check the IPM
module
Is it normal?
Yes
Change the outdoor PCB
About how to check the IPM module,please refer to IPM protection fault
HSU12/18VHJ(DB)
F19
LED1 flash 6 times
Supply voltage not as specified
or else parts damage may be occurred.
No
This question may be caused by the
power
No
Change the new one
66
Functions and control
Domestic Air Conditioner