Midea CD400 Service Manual

Shunde Midea Dishwasher Manufacturing Co., Ltd.

Dishwasher Service Manual

Midea

Life can be lovelier.

Fully Automatic Double Pump

For the sake of safe and efficient manipulation, you should prepare and learn to
use the following tools prior to servicing the dishwater: plus screwdriver, minus
screwdriver, H screwdriver, torque spanner, OTK caliper and universal meter.

Attention: never measure the resistance of live cord. Otherwise, you measuring

device may be damaged.

1. Dishwater does not work when
turned ON (No power indication).

Phenomena

Power socket defect.
Power cord defect.
Broken timer cord.
Lock malfunction.
Power switch failure.

Check socket.
See power cord.
See timer.
See door lock assembly.
See option switch and power switch.

Possible Causes

Service Instructions

Inlet valve core will not close.
Timer failure.

3. Overflowing incoming water.

Commonly Used Tools

Trouble Shooting

1

See protection and working
pressure switches.
See inner connecting wires.

Twisted inlet hose.
Excessive lower water pressure or
blocked water tap.
Inlet valve malfunction or blocked valve
filter.
Working pressure switch failure.

2. Small or no incoming
water.

4. Drainage activates again and
again without washing.

Working and protection
pressure switches failure.

See protection and working
pressure switches.
See inlet valve.
See timer.

Straighten up the inlet hose.
Check the water tap.
Check the inlet valve.
See protection and working
pressure switches and check
appropriate connecting wires.

5. Timer does not work.

6. Incomplete drainage.

7. Leakage.

Timer cord failure.
Timer failure.
Heating element failure (for heated
washing).
Thermostat failure.
Insufficient water.

See connecting wires.
See timer.
See heating element.
See thermostat.
See 2.

Twisted or blocked drain hose.
Pump motor failure.

Check drain hose.
See water pump motor assembly.

Tilted dishwater.
Unlocked door.
Broken connecting hose in
dishwasher.
Aged gasket.
Loose or defect inlet valve
connector.

Damaged pump.
Pump gasket failure.

Adjust the machine foot.
Lock the door.
Replace connecting hose.
Replace gasket.
Tighten the inlet valve. See inlet valve.
Reconnect the pump and the sump,
add gasket at the connector and
tighten the wedge.
See water pump motor assembly.

8. Dishwater powder retained in
the powder trough.

9. No brightness liquid from
dispenser.

10. Bad dispenser sealing

Caked dishwater powder.
Dishes block the water flow to the
dishwasher powder.

No brightness liquid in dispenser.
Electromagnetic valve does not
work.

See dishwater powder and
brightness liquid.
See loading of dishes.

See dispenser and inner
connecting wires.

Sealing cap failure.
Broken dispenser case.

Replace dispenser.

Protection or working pressure
switch failure.

Incorrect cord connection.

Many of the performance failures of the dishwasher are not the result of mechanical troubles. And the
unsatisfactory washing result can usually be corrected without any service.

This manual deals first with the problems in performance. To have satisfactory washing result, you have to use the
machine correctly. First thing first, the dishes shall be placed in a correct manner. If the machine works well and
the washing result is unsatisfactory, you should check the layout of the dishes as follows:

Load the dishes as instructed in the user's manual.
Preparation of the dishes such as dumping the remaining food, and removing from the dishes food lumps,
starches in particular, shall be done prior to loading.
The dishes shall face the water flow from the spray arm for free washing. Do not place the dishes in an
overlapped way.
Load heavy pans and large soup bowls downwards. If the upper racks are barred from water flows, do not
place articles on them any more.
Leave some space in the front of the wire basket so that the water flow may wash out the dishwater powder
from the powder trough in the inner door.
On the fork/knife rack, the tableware shall be placed with handle down evenly. Do not load there the
articles that may fall out from the bottom.

2

11. Unsatisfactory washing
result.

13. Water drops at the door.

12. Unsatisfactory drying.

14. Difficult opening/shutting
of the door.

15. Excessive working noise.

16. Water accumulated in
bottom pan.

Bad sealing of hose connectors.
Salt spoon, colophony spoon or
water tank leakage.
Incomplete sealing of inner
container from sump.
Incomplete sealing of thermostat.

Collision of dishes.
Vibrating pump motor assembly.
Foreign articles in the pump.
Loose screws.

Improper loading of dishes.

Aged, incorrect or insufficient dishwater
powder.
Improper procedure selection.
Twisted or blocked drain hose.
Foreign articles in the main washing
system.
Blocked spray arm.
Brightness liquid leaks into the inner
container during washing.
Filter screen not clipped to the right
position.

Improper loading of dishes.
Brightness liquid not used.
Heating element problem.
Heated wash mode not selected.

Condensed vapor from air
vent.

Dislocated door gasket.
Bent lock linkage.
Disalignment of lock hook.

See loading of dishes.
Add brightness liquid.
See heating element.
Reselect procedure.

Normal phenomena.

Press gasket back to position.
See door lock assembly.
See door lock assembly.

See loading of dishes.
See motor and pump assembly.

Check screws.

Check water hoses.
Check water softener (WP5F).

Check the contact.
Check the contact.

See loading of dishes.
See dishwasher powder and brightness
liquid.

Reselect procedure.
Check drain hose.

Clean spray arm.
Replace dispenser.
Clip filter screen to the right position.

Note: in the narration of this manual, the number in brackets behind the part stands for the serial

number of the part in the explosion diagram. The double pump model in the explosion
diagram is equipped with a WP5E. The actual configuration may be different.

III. Check of Performance: Loading of Dishes

IV. Check of Performance: Dishwasher Powder and Brightness Liquid

The water (pressure, hardness and temperature) and the dishwasher powder are the major elements that affect the
washing effect of the machine. Choose the right dishwasher powder and dosage according to the local water
condition, you will have satisfactory washing result.

Use only the fresh and dry dishwasher powder of the designated brand. Outdated powder will reduce the
washing effect.
Contact the local water supply company for the water condition, if applicable. The higher the water hardness is,
the more powder shall be used.

Check the brightness liquid in the dispenser and add without delay if it is insufficient. The brightness liquid

helps the water to drip, making the dishes easy to dry and curbing the formation of water specks on the surface
of the dishes.

¡¾Í¼1¡¿

A

B

¡¾Í¼2¡¿ ¡¾Í¼3¡¿

C

C

D

3

V. Power cord

The power cord of the dishwasher usually has a three-pin plug. Connect
the power supply as instructed in the user's manual.
If the dishwasher does not work, the power cord might be in the fault.
Most of the power cord troubles arise from damaged cord or loose
connection, and are visible.

Attention: to avoid electric shock, the power socket and power cord shall
be well grounded. Never use two-hole conversion connector that has no
ground terminals.

Steps for the check:

A. Disconnect the power prior to check.
b. Check the power plug. Improper connection may lead to bad contact.
c. Pull out the power plug in one stroke. Never pull at the power cord or use

a knife or other sharp tools that may cut the cord.

d. Check the power plug for overheat caused damage, corrosion or

looseness. In case of troubles, remove the outer casing (1) first, then the
rear panel (97) and replace the power cord (see Process 6).

e. Open the power cord clamp (96), remove the old power cord and replace

a new one with terminals. Secure the power terminals to the connection
terminals, and replace the power cord clamp.

f. Replace the rear panel and the outer casing.

VI. Removal of Outer Casing, Control Panel, Rear

This dishwasher is completely sealed. In order to repair internal parts, you have to remove the
outer casing before you can check and repair the parts.

Steps for the check:

a. Remove the three screws on the sides of the outer casing.

b. Open the door, and remove the six screws in the front of the inner container (see fig. 1 below). Note: do

not mix these stainless steel screws with the other ordinary ones.
c. Remove the seven screws in the back of the outer casing (see fig. 2 below).
d. Remove the screws in position D in fig. 2 below and take away the rear panel.
e. Lift up and away the outer casing from the dishwasher, and check and repair the internal parts.
f. Remove the six screws from the control panel bracing bar (58) (see fig. 3 below) and the two stainless

steel screws in position C of the inner container (see fig. 1 below), and pull out the control panel.
g. Remove the timer knob (see 1 in the appending diagram).
h. Turn the dishwasher upside down, remove all the screws in the bottom pan, open the cord clamp and

remove the bottom pan.

Turn all the switches to OFF and pull out the power cord plug.

An ohmmeter and the ability to read circuit diagrams are needed in this step.

Remove the outer casing.

Pull out the two input terminals of the timer motor and measure them with an ohmmeter (use the
range of R 100). If the pointer does not sweep partly across the line, replace the timer.

Refer to the circuit diagram to check the connection of the timer terminal to the elements.

4

VII. Check Internal Connecting Wire

The internal connecting wire connects the timer (60), the power switch (61), the inlet valve (95), the heating
elements (45) and other electric elements together. The wires shall be kept intact. Any damage to the wire
may cause overheat and result in broken wire. Common troubles to the internal connecting wire are broken
wire, bad connection terminal contact, and connection terminal insulation layer damages.

To repair the dishwasher, the ground shall be connected. When an electric component is replaced, check
whether the ground is connected again. This is a crucial step to avoid electric shock and short circuit.
Attention: to replace electric cord, use the cord of the same temperature resistance and specifications. The
specifications and temperature rise are marked on the cord.

Turn all the control knobs to OFF and pull out the power cord plug.
Open the outer casing, and, if necessary, remove the bottom pan.
Check the wires and connectors and replace the damaged ones.

Steps for the check:

VIII. Door Lock Assembly

Slider

micro switch

Micro switch spring

Linkage

The working mechanism of the door lock is that the linkage (8)
bolts up the door hook, which, in its turn, presses the micro switch
spring in the lock assembly to form a closed circuit. The lock
mechanism consists of the door lock holder (11), the slider (10)
and the micro switch (3). When the door is opened, the door hook
is withdrawn to release the micro switch, cutting the power supply
for open door protection.

In case of worn out slider, micro switch failure or deformed micro
switch spring, troubles may occur and the dishwasher will stop to
work as usual.

Steps for the check:

a. Pull out the power cord plug prior to servicing the door lock

mechanism.
b. Remove the outer casing.
c. If micro switch failure is the case, disconnect the micro switch,

remove the two screws and replace a new micro switch.
d. In case of deformed micro switch spring, adjust the spring

with nipper pliers so that the micro switch returns to its

original position when the slider is released and the micro

switch closes when the slider is pressed tight.

IX. Timer

The timer of the dishwasher consists of a synchronous motor and various switches, and controls the
various operations of the dishwasher automatically. The step motor, like a clock, runs at constant speed.
When it passes through the selected procedure, the internal switches will open or close at a precise
sequence, realizing the control of the circuit over the internal components.

The output cords of the timer are in different colors. With a copy of the circuit diagram in hand, you can
track the circuit from the timer to any element.

The timer is a very reliable unit. In case of dishwasher troubles, check other causes first before focusing
on and replacing the timer.

Steps for the check: