Mitsubishi Electric PUHZ-SW50VHA Service Manual page 35

Symptoms: Nothing is displayed on the remote controller. 3
Diagnosis flow
Check the voltage of the
terminal block (TB6) of
the remote controller.
10 to 16 V DC?
NO
Check the status
of the LED2.
Blinking
Check the status of the LED2
after disconnecting the remote
controller wire from the terminal
block (TB5) of the indoor unit.
Check the status
of the LED2.
Blinking
OCH525C
YES
Lighting
Lighting
35
LED display of the indoor
controller board
LED1 :
LED2 :
LED3 : —
Inspection method and
Cause
troubleshooting
• Defective • Replace the
remote controller remote controller.
• Breaking or poor • Check if there is breaking
contact of the remote or poor contact of the
controller wire remote controller wire.
Check the voltage of the
terminal block (TB5)
connecting the remote
controller wire.
If it is not between 10 and
16 V DC, the indoor
controller board must be
defective.
• The remote controller • Check if the remote
wire short-circuits controller wire is
short-circuited.
• Defective indoor • Replace the indoor
controller board controller board.
or