Mitsubishi Electric MJ-E14EG-S1-IT, Service Manual, Page: 11 / 39

11
Check the power supply
board P7 connector insertion
and the connector pins
Is dehumidi fi cation
taking place?
Is the blower fan motor rotating?
A
Firmly insert the
connectors or
connector pins
Check the resistance values
for the blower fan motor.
Normal:Between yellow and blue 217-236
Ω
Between black and blue 219-237 Ω
Abnormal:Open or shorted
Replace the blower fan motor
Replace the control board
Replace the power
supply board
NO
YES
NO NG
NG
NG
NG
OK
OK
NG
OK
OK
YES
B
Does the compressor operate?
Check the power supply board P2
and P3 (run capacitors) connector
insertions and connector pins
Raise the humidity in the
usage environment and check.
(Compressor stopped due to
abnormally low temperatures)
Firmly insert the
connectors or
connector pins
Check the motor protector
continuity
Normal: shorted
Abnormal: open
* Check it at normal temperature
with the power OFF.
Is the operating environment low
temperature (below 3.2°C)?
Check the resistance
values for the compressor
Normal: 24 to 27 Ω
between C-R
40 to 45 Ω
between C-S
Abnormal: Open or shorted
Is there an overcurrent?
(Surface is hot)
Replace the power supply
board
Replace the control board
Replace the motor
protector
Replace the
compressor
Replace the
compressor
NO
YES
YES
NO
OK
OK
OK
OK
NG
NG
OK
NG
OK
NG
NG
NG
NG
NG
OK
OK YES
OK
OK
NG
NO
Is the heat exchanger
(evaporator) cold?
Are the power consumption
and current normal?
Check the refrigerant
circuit (Leaks or blockages)
• The part of the cooler
near the tube temperature
sensor should be at least
10°C lower than room
temperature when normal.
• If the amount of
refrigerant is low due to
a slow leak, white frost
appears on the bottom
of the heat exchanger
Replace the parts
responsible for the
leaks or blockages
NO
NO
NG
OK
YES
C
YES