Mitsubishi Electric MJ-E14EG-S1-IT Service Manual page 11

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