Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 916

FDC-HKX
Indoor unit
Red LED *3 times flash
Green LED Keeps flashing
* Lamp OFF if remote controller wire is broken at power ON.
Is DC 10.8V de-
YES
tected between
remote controller
terminals (X)
(red) ~ (Z)(black)?
NO
Is DC10.8V detected
between indoor PCB
connectors (CNK) 1
(red) ~ 3 (black)?
NO
Defective indoor unit
PCB
Indoor unit
Stays OFF or Lights
Red LED
continuously
Stays OFF or Lights
Green LED
continuously
Power supply reset
914
Outdoor unit
Red LED
Green LED
Is voltage swing-
YES
ing at DC6 ~ 10V
between remote
controller termi-
nals (Y) (white)
~ (Z)(black)?
NO
Defective remote con-
troller PCB
YES
Broken or poor connec-
tion of remote controller
cord (red) or (black)
Outdoor unit
Red LED
Green LED
Is it normalized?
Defective indoor unit PCB
Replace. (Defective CPU)
Stays OFF
Keeps flashing
• Remote controller normal
voltage (DC)
X ~ Z: 10.5 ~ 10.8V
Y ~ Z: 5 ~ 10.8V
Is voltage swinging
at DC6 ~ 10V between
indoor PCB connestors (CNK)
2(white) ~
3(black)?
NO
Broken or poor connec-
tion of remote controller
cord (white) or (black)
Note (1)
If it is normalized by replacing the PCB, it should be judged the remote
controller or indoor unit PCB is defective (defective remote controller
communication circuit).
Stays OFF
Keeps flashing
YES
NO
Unit is normal.
(Interference by temporary
noise on remote controller
cords)
YES
Power sup- Is it
ply reset normalized?
Defective remote controller PCB
Replace. ... Defective indoor
unit PCB Replace.
Unit is normal.
(Runaway of indoor unit
CPU due to noise, etc.
Transient trouble)
YES
NO