Kuppersbusch EMWK 9600.0 User manual

Microwave oven
EMWK 9600.0 / 9800.0
MM
1 2 3 4 5 6
900900
600
360
180
90
600
360
180
90
P

Service Manual: H4-72-02-03
Responsible: Dieter Rutz KÜPPERSBUSCH HAUSGERÄTE AG
E-mail: [e-mail]
Phone: [phone] Kundendienst
Fax: [phone] Postfach 100 132
Date: 17.03.2006 45801 Gelsenkirchen

3 H4-72-02-03
For internal use only
Contents
1. Safety ............................................................................................................................... 4
1.1 Microwave warnings .............................................................................................. 5
1.2 Electric connection ................................................................................................5
1.3 Converter switch warnings .................................................................................... 5
2. Assembly ......................................................................................................................... 6
2.1 Disposing of the packaging and your old appliance .............................................. 6
2.2 Technical Data....................................................................................................... 6
3. Construction components ............................................................................................. 7
3.1 Power supply unit .................................................................................................. 7
4. Functions......................................................................................................................... 7
4.1 Demo mode (wiring for fairs) (EMWK 9800.0 only) ..............................................7
4.2 Children's safety device.........................................................................................7
4.3 Swelling arrow (EMWK 9800.0 only) .....................................................................8
4.4 Oven safety shutdown ........................................................................................... 8
5. Repairs............................................................................................................................. 9
5.1 Safety precautions - microwave energy ................................................................9
5.2 Checking the diode..............................................................................................10
5.3 Checking the converter switch.............................................................................10
5.4 Checking the safety switch .................................................................................. 11
5.5 Checking the hot-air fan motor ............................................................................12
5.6 Checking the antenna motor ...............................................................................12
5.7 Checking the magnetron, cross-flow and vapour filter ........................................ 12
5.8 Checking the power connection ..........................................................................13
5.9 Checking the ring heater .....................................................................................14
5.10 Checking the grill heater......................................................................................14
5.11 Checking the bottom heat....................................................................................14
5.12 Possible complaints from customers about the swelling arrow
(EMWK 9800.0 only) ...........................................................................................14
6. Cleaning......................................................................................................................... 15
7. Safety precautions during troubleshooting ............................................................... 16
7.1 Test program ....................................................................................................... 16
7.2 Testing the individual consumers ........................................................................ 17
7.3 Testing the converter...........................................................................................18
7.4 Testing the control elements ...............................................................................18
7.5 The debug mode ................................................................................................. 20
8. Leak test (leak indicator gauge) .................................................................................. 21
8.1 Abnormal operation (no-load operation)..............................................................21
8.2 Normal operation, loaded ....................................................................................21
9. Measuring the output power of the magnetron ......................................................... 22
10. Troubleshooting ........................................................................................................... 23
10.1 Error messages ................................................................................................... 24
10.2 Fault tracing tree.................................................................................................. 26

H4-72-02-03 4
For internal use only
1. Safety
The purpose of this service manual is to provide the customer service technicians who already have the
technical knowledge necessary to repair microwave ovens with specific information on the mode of
operation of the EMWK 9600/9800.0.
Danger!
Repairs may only be carried out by a qualified electrician!
Incorrect repairs can be extremely dangerous for the user!
To prevent electric shocks, please observe the following tips:
• In the event of faults, housing and frame may be live!
• Touching live components inside the appliance may cause dangerous currents to flow through your
body!
• Unplug the appliance before repair!
• When inspecting live parts, a residual current operated device must be used at all times!
• The ground wire resistance must not exceed that specified in the standard! It is of vital importance for
ensuring the safety of people and the functioning of the appliance.
• On completion of repairs, an inspection must be carried out in accordance with VDE 0701 [Associa-
tion of German Electrical Engineers] or the corresponding regulations for your country!
• On completion of repairs, a function and impermeability inspection must be carried out.
• On completion of the repair work a leak rate measurement must be made!
Note!
It is essential to observe the following notes in order to prevent damage to the appliance or the
components:
• The appliances must be disconnected from the mains prior to all repairs. If inspections must be car-
ried out on live appliances, make sure you use a residual current operated device.
• Do not take any measurements in the high-voltage circuit during operation. Risk to life and
limb!
• The mains plug of the microwave oven must always be accessible!
• Do not replace any components as long as the appliance is functioning.
• When looking for faults proceed systematically as outlined in the fault-finding steps.
• Observe EGB instructions.
• Never attempt repairs through the indiscriminate exchange of components!
• Always proceed systematically and observe the notes on troubleshooting!
• Do not take any measurements in the high-voltage circuit during operation. Risk to life and limb!

5 H4-72-02-03
For internal use only
1.1 Microwave warnings
• The microwave oven generates high voltages which may lead to serious or even fatal injury -
it is essential to observe the safety regulations contained in this repair manual at all times.
• Always disconnect the microwave from the mains prior to removing or installing components. Never
attempt to measure voltage on the inverter, the magnetron or high-voltage conducting wire. This
high-voltage circuit generates voltages exceeding 4000 volts.
• Always connect the microwave oven to a residual current overload circuit breaker prior to measuring
electric currents.
• Check to ensure that the power required by the oven does not exceed the nominal power of the
mains power supply.
• Pull the plug out of the mains socket and discharge the high-voltage capacitors of the converter
switch prior to removing or installing components.
• Connect the microwave oven with a twin-wire extension cable. The microwave oven must be
earthed. Looking for faults on a microwave oven that is not earthed is extremely dangerous.
• Carry out a functional test when repair work has been completed.
• Carry out a microwave leakage current test when repair work has been completed.
1.2 Electric connection
• Only connect the appliance to sockets with a safety fuse of at least 16 A. Please also check to
ensure that the main fuse in your home has a minimum output of at least 16 A so that it will not sud-
denly trip when the microwave oven is in operation.
• Before operation, check whether the mains voltage is the same as that indicated on the name/rating
plate of the appliance and whether the socket outlet is effectively earthed. The manufacturer
assumes no liability for damage which occurs through the non-observance of these regula-
tions.
1.3 Converter switch warnings
• The converter switch generates current of more than 4000 volts! Never attempt to measure the volt-
age in this switch.
• The aluminium dissipater on the converter switch gets very hot! Allow the dissipator to cool down
prior to removing the converter switch.
• Pull the plug out of the mains socket and discharge the high-power capacitors of the conversion
switch before removing the converter switch.
• The converter switch must be earthed. After replacing the converter switch tighten the earth terminal
and the earthed leads to the microwave oven casing. A converter switch with no earth connection
may be dangerous.

H4-72-02-03 6
For internal use only
2. Assembly
2.1 Disposing of the packaging and your old appliance
The packaging material for transport is fully recyclable.
Recycling the packaging saves raw materials and reduces the amount of waste. Disposed appliances
still contain useful materials. Take your old appliance to a recycling collection point. Please make your
old appliances unserviceable before disposing of it, to prevent it from misuse.
2.2 Technical Data
Voltage / Frequency 230V - 50Hz
Power consumption 6.7 A
Total electrical connection 3.6 kW
Microwave output 900 W (max) (5 levels)
Grill levels EMWK 9800.0 2500 W
EMWK 9600.0 2150 W
Appliance dimensions (WxHxD) 595 x 454 x 520 approx.
Niche dimensions (WxHxD) 562 x 450 x 550 mm approx.
Cooking cavity dimensions (WxHxD) 424 x 221 x 520 approx. (42 litres capacity)
EMWK 9800.0 EMWK 9600.0
12 oven functions 5 oven functions
3 Rack levels 3 Rack levels
6 memory programmes
Up to 3 microwave power levels in sequence
can be programmed
Up to 3 microwave power levels in sequence
can be programmed
Programmable electronic timer
with minute minder
Electronic clock with a timed control

7 H4-72-02-03
For internal use only
3. Construction components
3.1 Power supply unit
The power supply unit is a part of the relay board. It is essential to connect an earthed conductor (PE)
in order for the appliance to function properly.
Possible consequences if there is no earthed conductor
•If there is no PE connection
• The clock reference will be determined by the internal processor clock.
Error pattern: running deviations of the clock in the minutes section per day.
• If the power filter is not properly wired, the Y-capacitors will not be connected. Error pattern: the
Y-capacitors form a voltage divider. The appliance cabinet will be under half of the mains
voltage!
• Operation of the power filter will be very limited. Error pattern: radio screening.
• There will be no guarantee that the appliance is safe! It is absolutely essential for a protection
class I appliance to be connected to an earthed conductor
• The resistance to jamming of the appliance may be diminished due to the house wiring.
• In the event of the above-mentioned error patterns
• Check that an earthed conductor has been properly connected. If this is not the case the
appliance must be put out of operation and the customer must be notified accordingly!
4. Functions
4.1 Demo mode (wiring for fairs) (EMWK 9800.0 only)
Activate the demo mode
1. Press the memory button for approx. 4 seconds. The display will indicate: “Select your language”.
2. Select “English”.
3. Press the clock button for approx. 4 seconds. At the bottom on the right the display will show a “D”.
Deactivate the demo mode
1. Press the stop button for approx. 4 seconds. The “D” on the display will go off and the appliance will
be ready for operation again.
Please note! The demo mode will remain activated even if the power supply is cut off for a
longer period.
4.2 Children's safety device
Activating the child-proof lock
Press the stop button for approx. 4 seconds. The display will indicate “Child-proof lock”.
Deactivating the child-proof lock
Press the stop button for approx. 4 seconds. The lock will be released.

H4-72-02-03 8
For internal use only
4.3 Swelling arrow (EMWK 9800.0 only)
The swelling arrow indicates when the appliance has
reached the temperature set.
The display refers to 90% of the temperature set.
Here are two examples of different temperature settings.
4.4 Oven safety shutdown
4.4.1 EMWK 9600.0
The safety cut-off device is activated after 8 hours of operation.
Please note! The waiting time for the safety cut-off device is re-started every time a button is
pushed (or a knob is turned)!
4.4.2 EMWK 9800.0
The safety cut-off is activated irrespective of the temperature set.
30 - 100°C 24 hours
100 - 195°C 6 hours
200 - 245°C 3 hours
250 - 300°C 2 hours
Grill settings 2 hours
Please note! The waiting time for the safety cut-off device is restarted every time a button or
knob is activated.
Line Temperature set
120°C 250°C
7 90% 110°C 227°C
6 80% 100°C 204°C
5 70% 90°C 181°C
4 60% 80°C 158°C
3 40% 60°C 112°C
2 20% 40°C 66°C
1 Room
temperature 20°C 20°C
After
start
20%
40%
60%
70%
80%
90%

9 H4-72-02-03
For internal use only
5. Repairs
5.1 Safety precautions - microwave energy
Service technicians must never be exposed to the microwave radiation which can be
emitted by the magnetron or other components producing microwaves if the appliance
is not connected correctly or operated improperly.
All input and output connections, waveguides, flanges and seals are to be attached and
sealed correctly.
Never operate the appliance without having placed items in the cooking cavity which ab-
sorb the microwaves.
Never look into the open waveguide or the antenna when the. magnetron is live.
The appliance must never be operated without the housing or with the door open.
If the fuse blows, always block the system operability first (all microswitches) before the
appliance is switched on again. If a microswitch is defective, always replace all mi-
croswitches.
Before activation of the magnetron or before repair work, check the following points with all
appliances:
• The door does not close properly at the frame because it is deformed or the hinges are damaged.
• Door or door seal damaged
• Appliance obviously damaged
All defective or incorrectly set components in the locking, control, door locking, microwave generator and
transmission systems must be repaired, replaced or correctly set. Service technicians must first remove
their watches for all work on or near the magnetron.
•Attention!
The high-voltage capacitor could still be electrically charged about 30 sec. after the appliance has
been switched off. It is advisable to discharge the capacitor each time through both poles using a
suitably insulated cable. Secondary power circuits of the transformer have a high voltage and a low
amperage and for this reason it is extremely dangerous to work near these components if the appli-
ance is plugged into the mains. Never touch cables with your bare hands or with non-insulated tools
when the appliance is in operation.
• Do not measure the electric voltage of a high-voltage circuit or magnetron filament.
• Make sure that the door is not loose or is missing. If the screws are not tightened fully, this could lead
to the discharge of microwaves.
• Before you switch on the appliance, check that all electric connections are tight.
• Ensure with a reasonable procedure that no microwaves are emitted.
• Do not insert any metal objects either through the lamp gap or through any other gap as such objects
could act as an antenna and could result in the emission of microwaves.

H4-72-02-03 10
For internal use only
5.2 Checking the diode
1. Disconnect the high-voltage conducting wires from the magnetron.
2. Measure the resistance at the supply points. A good magnetron will have a heating filament resist-
ance of less than 1 Ω.
3. Measure the resistance between each terminal and the magnetron shell. The resistance between
each terminal and the shell of a good magnetron will be infinite.
Note!
• It is not possible to recognise all of the magnetron faults on the basis of resistance readings.
• It is difficult to determine an internal jump (short circuit) between anode and cathode.
• When examining the magnetron look out for burns around the antenna and for flawed magnets and
also check the terminals.
• It may also be possible to determine some magnetron faults by means of an audio test (buzzing and
rattling when the microwave oven is in operation).
5.3 Checking the converter switch
5.3.1 Checking the converter for a short circuit
The converter switch will probably have short-circuited if the 8A safety fuse of the microwave oven
triggers.
1. Disconnect all the conducting wires from the converter.
2. Remove the converter.
3. Check the three components indicated on the drawing by
measuring the switch resistance. Defect components will
generally have a very low resistance (almost 0 Ω).
Measuring point Normal Fault
Between the terminals < 1 Ω∞
Between terminal and shell ∞Fewer watts

11 H4-72-02-03
For internal use only
Q701 / Q702 (for adjusting resistance on a 9-V measuring
instrument)
DB701 (for diode adjusting on a 9-V measuring instrument)
5.3.2 Carrying out a check due to a short circuit
• Function of the cooling fan!
• Microwave oven has been installed in accordance with installation instructions!
• The ventilation slits are not blocked and air can enter!
5.4 Checking the safety switch
The safety switch ensures that no microwaves are generated when the door of the oven is open.
Main switch
• Cuts off the supply of 230V alternating current for converter switching.
Short-circuit switch
• If the main switch fails when the circuit is closed (short circuit) and the user then opens the door,
the monitoring switch will trigger a short circuit on the 230Vpower unit. The short circuit will acti-
vate the 10 A safety fuse and the short-circuited switching contacts will be fused together.
Signalling switch
• Reports the position of the door (open/closed) to the control module.
Checking the switch
1. Remove all of the leads from the three switches.
2. Check each switch for transmission with the door open and closed.
Normal Fault
Forwards Back Forwards Back
E-C > 1k Ω> 1k Ωapprox. 0 Ωapprox. 0 Ω
E-G > 1k Ω> 1k Ωapprox. 0 Ωapprox. 0 Ω
G-C > 1k Ω> 1k Ωapprox. 0 Ωapprox. 0 Ω
Forwards Back
+ – Reading ∞
~ ~ ∞∞
Door open Door closed
Main switch ∞Ωopen 0 Ωclosed
Signalling switch ∞Ωopen 0 Ωclosed
Short-circuit switch ∞Ωopen ∞Ωopen

H4-72-02-03 12
For internal use only
5.5 Checking the hot-air fan motor
1. Disconnect the power supply cables from the motor.
2. Measure the resistance of the motor winding when cold.
Normal: 150 Ω- 200 Ω
Fault: Low Ωreading or ∞
5.6 Checking the antenna motor
3. Disconnect the power supply cables from the motor.
4. Measure the resistance of the motor winding when cold.
Normal: 150 Ω- 200 Ω
Fault: Low Ωreading or ∞
5.7 Checking the magnetron, cross-flow and vapour filter
5. Disconnect the power supply cables from the motor.
6. Measure the resistance of the motor winding when cold.
5.7.1 Magnetron fan
Normal: 200 Ω- 200 Ω
Fault: Low Ωreading or ∞
5.7.2 Cross-flow fan
Normal: 1 - 2: 150 Ω- 200 Ω
1 - 3: 170 Ω- 190 Ω
2 - 3: 70 Ω- 90 Ω-
Fault: Low Ωreading or ∞
5.7.3 Vapour fan
Normal: 2 - 3: 610 Ω- 630 Ω
2 - 4: 350 Ω- 370 Ω
3 - 4: 240 Ω- 260 Ω-
Fault Low Ωreading or ∞

13 H4-72-02-03
For internal use only
5.8 Checking the power connection
The following approximate voltages must be measured on the connection points when the mains plug is
plugged in or when the mains cable has been connected.
400 V mains, 3-phase (most widely used in Germany and Europe)
230 V mains, 3-phase (still used in parts of Europe, e.g. in France and Belgium)
230 V mains, 2-phase, symmetrical voltage distribution (still used in parts of Europe, but
seldom, e.g. in France and Belgium)
The functioning of the appliance is limited with this power supply. Running deviations of the clock in the
minute section per day, since the clock reference cannot be taken from the power frequency. The clock
reference in this case is the internal processor clock.
Please note! The F901 (8A) fuse is not a part of the power unit. It is in the electric circuit of the MW
power supply.
When the fuse is triggered the electronic module (relay board) must not generally be
replaced. The MW components will need to be checked for a fault and the fault rectified.
(Exception: The short circuit has damaged the strip conductors (visual check).
Terminals Reading
X19 / X20 30 V~ or 240 V~
X19 / X18 approx. 0 V or 230 V~ or 240 V~
X20 / X18 230 V~ or 240 V~ approx. 0 V
Terminals Reading
X19 / X20 230 V
X19 / X18 133 V~
X20 / X18 133 V~
Terminals Reading
X19 / X20 230 V~
X19 / X18 115 V~
X20 / X18 115 V~

H4-72-02-03 14
For internal use only
5.9 Checking the ring heater
7. Disconnect the power supply cables from the heater.
8. Measure the resistance of the heater element when
cold.
Normal: 80 Ω- 90 Ω
Fault: Low Ωreading or ∞
5.10 Checking the grill heater
9. Disconnect the power supply cables from the heater.
10.Measure the resistance of the heater element
when cold.
Normal: external: 40 Ω- 60 Ω
internal: 30 Ω- 50 Ω
Fault: Low Ωreading or ∞
5.11 Checking the bottom heat
11.Disconnect the power supply cables from the heater.
12.Measure the resistance of the heater element when cold.
Normal: 30 Ω- 50 Ω
Fault: Low Ωreading or ∞
5.12 Possible complaints from customers about the swelling arrow
(EMWK 9800.0 only)
If food is very moist or if the food comprises water (baking tray filled with water for preserving food) or if
the load is large (baking on several levels) the last segment of the swelling arrow may not be switched
on.
The temperature will still be regulated in the oven without any restrictions. Baking and cooking results
will not be affected.
Any complaints which may be made are unjustified.

15 H4-72-02-03
For internal use only
6. Cleaning
Prior to all maintenance or cleaning work always pull out the mains plug and wait until the appli-
ance has cooled down.
The cavity is made of stainless steel and therefore cleaning is extremely easy. Always keep the cover
panel of the microwave outlet opening free of oil and grease splashes.
Never use scouring agents, metal wool or sharp metal objects for cleaning the cavity. Moreover, make
sure that no water or liquid cleaning agent enters the waste air and vapour extractor slits on the top of
the appliance.
No alcohol, scouring agents or ammonia-containing cleaning agents are to be used for cleaning the in-
side and outside of the door.
To ensure perfect closing, always keep the inside of the door clean and make sure that dirt and food
residues are not jammed between the door and the appliance front.
Regularly clean the fresh air openings on the rear of the appliance and the surface under the turntable
so that they do not become clogged with dust and dirt over the course of time. Please contact the
Customer service to check the fresh air openings on the rear of the appliance.

H4-72-02-03 16
For internal use only
7. Safety precautions during troubleshooting
Before it leaves the factory, every appliance is carefully checked but it must be correctly installed and
operated. In spite of all safety measures, safety depends on correct installation and correct operation
and maintenance by the customer.
Service technicians must never be exposed to the microwave radiation which can be
emitted by the magnetron or other components producing microwaves if the appliance is
not connected correctly or operated improperly. Make sure you observe the following
instructions ”5.1 Safety precautions - microwave energy” on page 9.
7.1 Test program
Activating the test program
The test program can only be carried out when the power network has been reset (max. time after reset
of 5 min.)
The following steps must be taken to activate the test program:
1. Press the clock button.
2. Press 90 W.
3. Press the clock button.
4. Press 900 W.
5. Press the start button.
Acknowledgement appears in the text display, all of the segments light up and a signal will sound.
Acknowledgement of a program start with door open/close or only door close.
Line 1 of the LED display will show “Test” and line 2 will show the software status of the electronic unit.
If the door is opened again line 2 of the display will show “Close door”.
Deactivating the test program
1. Cut off the power supply.
2. Press the stop button for approx. 6 seconds.
3. Do not press any buttons for 10 minutes.
Once the test program has been activated the following tests may be carried out:
• Testing the individual consumers
• Testing the converter
• The debug mode
• Testing the control elements

17 H4-72-02-03
For internal use only
7.2 Testing the individual consumers
7.2.1 EMWK 9600.0
Start up the test program.
7.2.2 EMWK 9800.0
Start up the test program.
Buttons to press Symbols
displayed
Clock
display
Consumers
Press the clock button
once
01
Press the plus or minus
button
None A1 Time, end (opener)
A2 Cooling fan + magnetron fan + vapour fan
A3 Antenna motor + converter
A4 Oven lamp
Buttons to press Symbols dis-
played
Clock
display
Text
display
Consumers
Turn the temperature knob
clockwise (one lock-in)
None Test
Output
Turn the program knob
clockwise (one lock-in
each)
A1:A6 Grill, interior + oven lamp
A2:A6 Grill, exterior + oven lamp
A3:A6 Ring heater + oven lamp
A4:A6 Bottom heat + oven lamp
A6 Universal disconnection +
oven lamp
A7 Magnetron fan + cooler fan
A8 Vapour fan, slow
A9 Vapour fan, fast
A11 Antenna motor + converter +
oven lamp
A12 Recirculation motor

H4-72-02-03 18
For internal use only
7.3 Testing the converter
1. Start up the test program.
2. Turn the temperature knob clockwise (three lock-ins).
Display: Test converter
Water Load
3. Press the start button.
Test is carried out at 900W for 2 minutes. Only carry out the test with the door closed!!!
Once the test has been completed a corresponding error message will be shown in the clock display.
Possible error messages are indicated under ”10. Troubleshooting” on page 23 .
7.4 Testing the control elements
7.4.1 EMWK 9600.0
Start up the test program.
Buttons to press Symbols
shown Clock display
Press the clock button once LED_CLOCK 02
Door contact open None 00:
Door contact closed None :00
MW power button 90 W LED_MW1 11:11
MW power button 180 W LED_MW2 22:22
MW power button 360 W LED_MW3 33:33
MW power button 600 W LED_MW4 44:44
MW power button 900 W LED_MW5 55:55
Start button None 0S:00
Stop button None 0S:01 + and error signal (no time limit)

19 H4-72-02-03
For internal use only
7.4.2 EMWK 9800.0
Start up the test program.
Buttons to press Symbols
shown Clock display Text display
Turn the program knob clock-
wise (two lock-ins)
None Test
Input
Door contact open None 00:
Door contact closed None :00
MW power button 90 W LED_MW1 11:11
MW power button 180 W LED_MW2 22:22
MW power button 360 W LED_MW3 33:33
MW power button 600 W LED_MW4 44:44
MW power button 900 W LED_MW5 55:55
Button for changing the line in
the text display
None . kg
Rapid heating button LED_rapid heating
Memory button LED_Memory 1 2 3 4 5 6
Clock button LED_clock ¨|
Minute minder button LED_MM h min
Start button None 0S:00
Stop button None 0S:01 + and error signal
(no time limit)

H4-72-02-03 20
For internal use only
7.5 The debug mode
7.5.1 EMWK 9600.0
Start up the test program.
7.5.2 EMWK 9800.0
Start up the test program.
Possible error messages are indicated under ”10. Troubleshooting” on page 23.
Buttons to press Symbol
display
Clock
display Designation
Press the clock button once None 04
Start button Start the debug mode
Any button None • Timer 10x faster
Error has occurred Error • Error shown in the clock display
Buttons to press Symbol
display
Clock
display
Text
display Designation
Turn the temperature
knob clockwise
(fourth lock-in)
None None Test
debug
Mode
Start button Oven tem-
perature
Start the debug mode
Any button • Timer 10x faster
• Temperature setting in line 2 of
the text display
• Error shown in the clock display
Error has occurred Error