Mitsubishi Electric MJ-E14EG-S1-IT User manual

2013
DEHUMIDIFIER
SERVICE MANUAL
Model MJ-E14EG-S1-IT
No.MJW-E-13020
Sold from 2014
CONTENTS
1. Precautions 2
2. Names and Functions of Parts 4
3. Specifications 5
4. Outer Dimensions 5
5. Wiring Diagram 6
6. Function 7
7. Technical Points 8
8. Precautions for failure diagnosis 9
9. Troubleshooting Procedure 10
10. Troubleshooting 18
11. Maintenance 20
12. Service Checklist 21
13. Precautions for Disassembly and Reassembly 22
14. Disassembly and Reassembly Hints 24
15. Parts Catalog 34

2
1. Precautions
2
Note) This page is extracted from the instruction manual.

33
Note) This page is extracted from the instruction manual.

4
2. Names and Functions of Parts Note) This page is extracted from the instruction manual.

5
3. Specifications
4. Outer Dimensions
Note) This page is extracted from the instruction manual.
238
160 80 210
360
534

6
P1
P3 P6 P12P13
HUM.S
P9 P11 P20 P21
P100 P101
P7
P30 P50
P15
VDD GND
P40
P2
CRS
Operation control
board
Control boardPower supply board
5. Wiring Diagram
1) Wiring Diagram
2) Board Diagram
[Operation control board]
[Power supply board]
[Control board]
Com-
pressor
Capacitor for
compressor Fan Solenoid
Valve
White
Red
Gray Gray
Black
Yellow
Blue Blue
Yellow/Green
Blue
Brown
Power plug
Humidity
sensor
Room
temperature
sensor
Thermopile
(Move Eye)
Ambient
tempera-
ture
Object
tempera-
ture
Float switch
Gray
Blue
White White White
Gray
Tube
temperature
thermistor
Stepping
motor
(left/right)
Stepping
motor
(up/down)

7
6. Function
Function List
Operation Off
Operating mode
Laundry Mildew guard Low High Auto Defrosting detection Tank full detection (Dehumidify) Tank full detection (Move Eye) Tank full protection Drying inside ON timer setup in progress ON timer setup complete
Blower fan OFF ON ON ON ON ON/OFF ON ON ON OFF ON/OFF OFF OFF
Compressor OFF ON ON ON ON
ON/OFF OFF OFF OFF OFF OFF OFF OFF
Up-down louvre CLOSE ON ON *1 *1 *1*3 *1*4 *1 ON OFF Top
centre
CLOSE CLOSE
Left-right louvre Centre ON ON *2 *2 *2*3 *2*4 *2 ON OFF Centre Centre Centre
LED indicator
POWER Flashing
FULL
DRYING INSIDE
LCD indicator
7-segment Current humidity display (3-second display of set humidity only when SELECTION is selected)
Operation mode Selected operating mode lamp lit Flashing Lit
MOVE EYE *4 *4 *4
TIMER Set OFF timer time display ON timer time display
Up-down swing area *1 *1, *5 *1 *1 *1
Up-down swing monitor *1
Left-right swing area *2 *2, *5 *2 *2 *2
Left-right swing monitor *2
CHILD LOOK Lit when child lock is ON
Switch
POWER
MOVE EYE *6 *6
DEHUMIDIFY *6 *6
SWING *5 *5 *5
SWING *5 *5 *5
DRYING INSIDE
TIMER *7
CHILD LOCK
*1: Operates when ON is selected for the up-down louvre. Stops when OFF is selected.
*2: Operates when ON is selected for the left-right louvre. Stops when OFF is selected.
*3: Operates when the blower fan is running
*4: Can only operate when using MOVE EYE (LAUNDRY, MILDEW GUARD) mode.
*5: Can only operate when using DEHUMIDIFY (LOW, HIGH, AUTO) mode.
*6: Operation mode moves to “tank full protection” when the switch is pressed.
*7: Can operate as the ON timer setting
: Lit/Can operate
: Unlit/Stopped/Cannot operate
When MOVE EYE is to be turned OFF (MOVE EYE operating mode only)
If MOVE EYE is to be turned OFF when it is in MOVE EYE operating mode, turn the power OFF and press
the MOVE EYE switch for at least 3 seconds.
Follow the same procedure to turn operations ON.
MOVE EYE is ON at the time of factory shipment.
This dehumidifier remembers whether MOVE EYE is ON or OFF.
Even if the power plug is pulled out or power is turned OFF, operations start with the same setting that
was previously set.

8
7. Technical Points Note) This page is extracted from the instruction manual.

9
8. Precautions for failure diagnosis
The following precautions should be observed in order to perform troubleshooting safely and correctly.
The following diagrams indicate circumstances where danger can result from mishandling the unit.
WARNING
Mishandling may result in fatal or serious injury, or fire.
CAUTION
Mishandling may result in injuries or damage to your home or property, etc.
Forbidden Always follow the
instructions Alert
Meanings of graphic symbols are explained below.
Remove the power plug
from the socket.
Failure to do so may cause electric shock or injuries.
When performing work with
the power on, be careful not
to touch the live part.
This may cause electric shock.
Do not touch a rotating object
until it completely stops.
The rotating object may catch your hand etc,
and result in injuries.
Do not work with wet hands.
This may cause electric shock.
Check the wiring diagram
before wiring processing.
Failure to do so may cause combustion,
generation of smoke, and/or malfunction.
After the work,
lay the wire out as it was before.
Failure to do so may cause combustion,
generation of smoke, and/or malfunction.
Unplug Electric shock
Don't touch No wet hands
Check Return to
as it was
WARNING
Wear protective gloves.
Failure to do so may result in injuries
by the edge of metal, electric shock,
and/or burns caused by contact with hot section.
Keep children away.
Failure to do so may result in
electric shock and/or injuries when moving
the unit or using a measuring device.
Wear gloves Keep away
CAUTION

10
9. Troubleshooting procedure
1) Failure diagnosis flowchart
Do any of the following
errors appear on the
humidity indicator?
“E0” “E1” “E2” “E3” “E4”
“E5” “E7” “E8” “A1” “A2”
“A6” “A8” “P4”
Perform the recommended
actions described in “Error
Indications and Corrective
Actions” on page 16.
Check the continuity of current
fuse on the power supply board
FUSE1 : 10A FUSE2/3 : 2A
CHILD LOCK indicator
turns on
When the POWER switch is
turned ON, does the operating
mode lamp turn on?
Deactivate the child lock
Check the power cord conduction Replace the power cord
Replace the power
supply board
Does the detection buzzer
beep when the POWER
switch is turned ON?
Check if the lamps on the
control panel turn on.
* How to turn on all of the
lamps (See “LED and
Monitor indicators” on
page 17)
* Check whether any of the
LEDs on the operation
control board have fallen
off (repair if an LED has
fallen off)
Check that the power
supply board, control
board and operation
control board connectors
are firmly connected
(carefully check whether
any of the connector pins
have been pulled out,
etc.).
Firmly insert the
connectors or
connector pins in
the trouble spots
Replace the operation
control board
Replace the control
board
Replace the power
supply board
Is the FULL lamp lit? Is the tank full?
Drain the water from the tank
Float check:
• Is the float switch disconnected
or installed reversely?
• Is the float operation smooth?
• Is there a magnet attached
to the float?
Repair the float problem
Check the float switch
• Check the control board
P12 connector insertion
and the connector pins
• Check the continuity
between the P12
connector terminals when
the water tank is installed
Normal . . . When tank is
full: shorted
When tank is empty: open
Replace the float switch
Replace the control board
Replace the power
supply board
A
YES
YES
NO
NO
YES YES OK
NG
NG
OK
OK
OK
NG NG
NG
NG
NG
OK
OK
NGNO
OK
OK
NG
NG
NG
OK
NG
NG OK
OK
OK
OK
YES
YES
NO
NO
YES
YES
NO

11
Check the power supply
board P7 connector insertion
and the connector pins
Is dehumidification
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 217-236Ω
Between black and blue 219-237Ω
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
OKYES
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

12
B
D
The unit stops working
in the middle of operation
Check the resistance values
for the tube temperature.
Normal: 8.0KΩto 20.8KΩ
(Between P15 pins)
Abnormal:Open or shorted
Check the resistance values
for the solenoid valve.
Normal: 2.0KΩto 2.2KΩ
(Between the pin1 and pin2)
Abnormal:Open or shorted
Replace the tube
temperature thermistor
Replace the solenoid valve
The louvre does not
swing
C
Is the filter blocked due to dust, etc.?
Is the operating environment low
humidity or low temperature?
The main unit is operating
normally.
Check the operating environment
again, and then operate again.
Is the operation being
performed with the unit set to
automatic operating mode?
(LAUNDRY/MILDEW
GUARD/AUTO/OFF TIMER)
①LAUNDRY: A minimum of about 84 minutes to a maximum of about 12 hours
②MILDEW GUARD: A minimum of about 4 hours to a maximum of about 12 hours
③AUTO: If the current humidity goes lower than the set humidity, operation stops.
④OFF TIMER: Has the timer stopped operating? Operation stops at the set time.
⑤Is the OFF timer being used at the same time as timer OFF for all operating modes?
Operation stops at the set time as timer operation is given priority.
The main unit is operating normally if ①through ⑤are true.
Is the up-down swing louvre
OFF?
Check the connector connection
between the control board P11
connection and the stepping motor
connector and connector pins.
Check the resistance values
between the stepping motor
connector pins.
Normal
Terminals 1-2
Terminals 1-3 342Ωto 418Ω
Terminals 1-4
Terminals 1-5
Abnormal
Open or shorted
E
Replace the control board
Replace the control board
Replace the power supply board
Replace the power supply board
Clean filter
Normal. Dehumidification
may not be possible in low
humidity and low temperature
environments.
Explain the performance curve
on page 8.
Is the dehumidifier installed
in a low humidity, low
temperature environment?
Does the up-down swing
louvre change to Wide,
Frontward, and Upward?
Firmly insert the
connectors or connector
pins in the trouble spots
Replace the stepping motor
Dehumidification
may not be possible
in a low humidity,
low temperature
environment. Explain
the performance
curve on page 8.
Normal
Replace the control
board
Replace the power
supply board
OK
OK
OK
OK
NG
NG
YES
OK
OK
NO
YES
NO OK
NG
NG
NG
NG
NG
YESYES
YES
NO
YES YES YES
NO
NO NO
OK
OK
NG
NG NG OK
OK
NO
OK
OK
NG

13
D
F
MOVE EYE operation
is abnormal
Is the left-right swing louvre
stopped? Normal
E
YES
NO
Does the left-right swing
change to Wide and Stop
swing operation?
Check the connection
between the control board
P9 connector and the
stepping motor as well as the
connector pins.
Firmly insert the
connectors or connector
pins in the trouble spots
Check the resistance values
between the stepping motor
connector pins.
Normal
Terminals 1-2
Terminals 1-3 342Ωto 418Ω
Terminals 1-4
Terminals 1-5
Abnormal
Open or shorted
Replace the stepping
motor Replace the control
board
Replace the power
supply board
Is the operating mode the
MOVE EYE operating mode?
Is the MOVE EYE monitor on
the control panel lit?
Check the control board P40
connector insertion and the
connector pins
See “LED and Monitor indicators” on page 17 of the Troubleshooting
procedure. Press the MOVE EYE switch and the DEHUMIDIFY
switch 4 times at the same time when the POWER switch is OFF,
and then set the POWER switch to ON within 2 seconds.
After it starts up, select the mode with the TIMER switch. Press the
TIMER switch 6 times to select the mode 6. (the selected mode
number is displayed in the timer display)
Check method: Cover the MOVE EYE sensor with the palm of the
hand, and check whether the humidity display shows approximately 35.
Replace the move eye
How to check the MOVE EYE and louvre operations: Hang a wet
towel on a wall with no window or heat source.
Run with the dehumidifier operating mode set to LAUNDRY
operating mode. Check that the MOVE EYE monitor is lit. MOVE
EYE and louvre operation is normal if 3 minutes after it starts up,
the area where air blows out from the main unit gradually narrows
and the air hits the centre of the towel being dried.
MOVE EYE is OFF. Turn the POWER switch
OFF and press the MOVE EYE switch for about 3
seconds. When the detector beeps and the MOVE
EYE operating mode is set to LAUNDRY or MILDEW
GUARD, does the MOVE EYE monitor turn on?
Normal
Repair the control board
P40 connector
Replace the control board
Replace the power supply
board
YES YES
NG
NO
OK
NO
OK
OK
NG
NG
OK
OK
OK
NG
NO YES
YES
NO NO
YES
YES
OKNG
NO
OK
OK
NG OK
OK
NG
NG

14
F
Amount of
dehumidification is low
Is there dust or dirt on the
room temperature sensor?
YES
NO
Replace the room
temperature sensor
Remove the dust or
dirt from the room
temperature sensor
Check the control board P13
connector insertion and the
connector pins
Firmly insert the
connectors or connector
pins in the trouble spots
Check the resistance values for
the room temperature sensor
Connector pins (between 3-4)
Normal: 8 to 20.8KΩ
Abnormal: Open or shorted
Is there dust or dirt on the
humidity sensor?
Remove the dust or dirt
from the humidity sensor
Replace the control board
Check the humidity sensor
operation
(Hold a steaming towel or hot
air from a dryer close to the
humidity sensor for 1 minute.
If the humidity indicator rises,
it is OK.)
Normal
YES
YES
NG
NG
YES
NG
NO
NO
OK
OK
NO
OK
OK
OK
Is the dehumidifier installed
in a low humidity, low
temperature environment?
The unit is normal.
Dehumidification may
not be possible in a
low humidity and low
temperature environment.
Explain the performance
curve on page 8.
OK
OK
OK

15
2) Simple Check Table for Main Parts
Part name Test criteria
Tube temperature
detection thermistor
Disconnect the connector and measure the resistance values with a tester (Part temperature
10°C to 30°C).
Normal Abnormal
8.0KΩto 20.8KΩOpen or shorted
Room temperature
sensor
Disconnect the connector and measure the resistance values with a tester (Part temperature
10°C to 30°C).
Normal .............8.0 to 20.8KΩ(between pins 3-4)
Abnormal .........Open or shorted
Compressor
Disconnect the connector and measure the resistance values across terminals with a tester
(Coil temperature 10°C to 30°C).
Normal Abnormal
C-R side 24Ωto 27Ω
Open or shorted
C-S side 40Ωto 45Ω
Blower fan motor
Measure the resistance values across terminals with a tester (Part temperature: 10°C to
30°C).
Normal Abormal
Yellow-Blue 217Ωto 236Ω
Open or shorted
Black-Blue 219Ωto 237Ω
* Be careful of injury or shock
Solenoid valve coil
Measure the resistance values across terminals with a tester (Part temperature: 10°C to
30°C).
Normal Abnormal
2.0KΩto 2.2KΩOpen or shorted
Stepping motor
Measure the resistance values across terminals with a tester (Part temperature: approx
25°C).
Normal Abnormal
Terminals 1-2
342Ωto 418ΩOpen or shorted
Terminals 1-3
Terminals 1-4
Terminals 1-5

16
3) Error Indications and Corrective Actions
Indicator
(current humidity
display)
Error (failure) Corrective action
A1 Microprocessor failure
RAM error Replace the control board
A2 Frequency determination error
Check the outlet, 220V power
(Try to replace the power supply and control
boards)
A6 Watchdog error
(Main stop/Interrupt) Replace the control board
A8 E2PROM failure Replace the control board
E0 Room temperature sensor
disconnected Check the P13 connector connection
Check the room temperature sensor board
E1 Room temperature sensor short
E2
Move eye thermopile
OBJ High temperature abnormal
(object temperature)
Check the connectors
Replace the move eye thermopile
E3
Move eye thermopile
OBJ Low temperature abnormal
(object temperature)
Check the connectors and the disconnection
Replace the move eye thermopile
E4
Move eye thermopile
AMB High temperature
abnormal (ambient temperature)
Check the connectors
Replace the move eye thermopile
E5
Move eye thermopile
AMB Low temperature abnormal
(ambient temperature)
Check the connectors and the disconnection
Replace the move eye thermopile
E7 Tube temperature thermistor
disconnected Check the connectors
Check the P15 tube temperature thermistor
connection
E8 Tube temperature thermistor
short
P4 Compressor failure
Check the air flow
Check the tube temperature thermistor
Check the compressor operating noise
4) Self Diagnostic Test Program
(1) Deactivate 3-minute restart prevention
Start . . . . . . . . . .Press the MOVE EYE and DEHUMIDIFY switches together 3 times when
the power is off. Press the POWER switch within 2 seconds.
Functions . . . . . . .①Deactivates 3-minute restart (immediate operation)
②Sets the operating mode to LAUNDRY
③When E2PROM error is detected, FULL LED and CHILD LOCK monitor
are lit.
④Turns the solenoid valve ON for 3 seconds when the power is off, and
then after 3 seconds, turns the solenoid valve OFF.
⑤When the operating mode changes, it fixes the fan rank and unlocks the
E2PROM error display.
Finish . . . . . . . . .Turn the power OFF.

17


Microprocessor
version display
Current
humidity
indicator
Room
temperature
indicator
(1°C increments)
Room temperature
indicator
(0.2°C increments)
Tube temperature
indicator
(1°C increments)
Tube temperature
indicator
(0.2°C
increments)
Move eye
thermopile
OBJ indicator
(1°C
increments)
Move eye
thermopile
OBJ indicator
(0.2°C
increments)
MOVE EYE
AMB indicator
Fan rank
indicator
Blower fan
operation
cumulative time
(Top 8 bits)
Blower fan
operation
cumulative time
(Bottom 8 bits)
Current
sensitivity
table
7 seg + All
LEDs lit
(2) LED and Monitor indicators
Start . . . . . . . . . .Press the MOVE EYE and DEHUMIDIFY switches together 4 times when
the power is off. Press the POWER switch within 2 seconds.
Mode selection . . . .Use the TIMER switch to change the diagnostic mode (0 to 13). The selected
mode number is displayed in the timer display.
Finish . . . . . . . . .Turn the power OFF.
How to display the humidity
indicator by diagnostic mode
In decimal : 0, 1, 2, 4, 6, 8, 9, 10, 13
In hexadecimal : 3, 5, 7, 11, 12
(3) Demo mode
Start . . . . . . . . . .Hold the MOVE EYE and DEHUMIDIFY switches together when the power
is off and press the POWER switch.
Operations . . . . . .①Demo mode continues until the microprocessor is reset
②All of the switches are disabled
③Operates the same way as when in LAUNDRY mode except for the
compressor and the blower fan.
Finish . . . . . . . . .Turn the power OFF.
(4) Error history check mode
Start . . . . . . . . . .Press the MOVE EYE and DEHUMIDIFY switches together 5 times when
the power is off. Press the POWER switch within 2 seconds.
Mode selection . . . .Use the TIMER switch to change the diagnostic mode (0 to 7).
Operations . . . . . .①Mode 0: Newest error history display
②Mode 7: Oldest error history display
Finish . . . . . . . . .Turn the power OFF.

18
Note) This page is extracted from the instruction manual.
10. Troubleshooting

19
Note) This page is extracted from the instruction manual.

20
11. Maintenance Note) This page is extracted from the instruction manual.