Mitsubishi Electric EHST20C-VM6HB Service Manual page 42

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 of the indoor unit.
Check the status
of the LED2.
Blinking
OCH533D
YES
Lighting
Lighting
Cause
• Defective
remote controller
• Breaking or poor
contact of the remote
controller wire
• The remote controller
wire short-circuits
• Defective indoor
controller board
42
LED display of the indoor
controller board
LED1 :
LED2 : or
LED3 : —
Inspection method and
troubleshooting
• Replace the
remote controller.
• Check if there is breaking
or poor contact of the
remote controller wire.
Check the voltage of the
terminal block connecting
the remote controller wire.
If it is not between 10 and
16 V DC, the indoor
controller board must be
defective.
• Check if the remote
controller wire is
short-circuited.
• Replace the indoor
controller board.