Inverter NN-CT880MBPQ User manual

HAD1003004C2
Microwave Oven
NN-CT880MBPQ
NN-CT870WBPQ
32L
United Kingdom
©Panasonic Home Appliance Division 2010. Unauthorized copying
and distribution is a violation of law.

NN-CT880MBPQ NN-CT870WBPQ
2
1 Contents
1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2 Inverter Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3 Feature Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
4 Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
5 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . 5
6 Schematic Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
7 Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
8 Description of the Operation Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
9 Cautions to be Observed when Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
10 Part Replacement Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
11 Component Test Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
12 Measurements and Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
13 Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
14 Exploded View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
15 Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
16 Door Assy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
17 Escutcheon Base. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
18 Packing and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
19 Trim Kit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
20 Digital Programmer Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
21 Key Board Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Power source 230V - 240V AC Single Phase 50Hz
Power requirements Microwave 1200W
Grill 1560W
Convection 1300W
Combi 2700W
Output (IEC60705) Microwave 1000W
Grill 1500W
Convection 1250W
Microwave frequency 2450Mhz
Timer 99 min 99 second
Oven cavity size 32L
Outside dimensions 530mm(W) x 508mm(D) X 344MM (H)
Inside dimensions 350mm(W) X 360mm(D) x 250mm(H)
Weight 21Kg

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2 Inverter Warning
The inverter board looks like a regular PCB, however, this PCB
drives the magnetron tube using very high voltages and cur-
rent.
It has
1. Very high voltage and high current
2. An Aluminium heat sink that becomes very hot
3. The capacitors on the inverter circuit will contain a high
voltage charge even when the oven is not operating.
Do not
1. Do not touch the circuitry as it contains very high volt-
ages. When replacing the board please take extreme
care to avoid possible electric shock. High voltages may
remain in the circuit.
2. Do not touch the aluminium heat sink as it will become
very hot. It also contains high voltages.
3. Do not attempt to repair the inverter PCB as this can be
very dangerous. Replace the high voltage inverter circuit
as a complete unit. Return the old unit fully repacked
in the original shipping box and completed paper
work.
4. Do not adjust or tamper with the preset volume on the
inverter board. It is very dangerous to adjust this preset
without proper test equipment.
5. Do not test the oven while the inverter grounding strip or
screws are loose. It is very dangerous to operate the
inverter circuit board without a proper ground connection.
Inverter Grounding
Figure 1
Inverter PCB layout
Figure 2
3 Feature Chart
Function BPQ
Microwave 6
Grill 3
Convection 17
Combi Yes
Sensor Reheat 0
Sensor Cook 5
Sensor Combi 8
Sensor Crisp -
Weight Defrost 3
Weight Combi 5
Weight Reheat -
Weight Cook -
Memory Cook 3
Weight Crisp -
Stage Cooking 3 stage
Delay / Stand Yes
More / Less Yes
Kg -> lb/oz Yes
Clock 24H
Word Prompt English
Step by Step LED

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4 Control Panel
Chaos
Defrost
Vegetables
Potatoes
Fish
Pizza
Meat
Crispy Top
Chicken
Bake
10
min
1
min
10
sec
1
h
Micro Power Grill 1-2-3
Convection
Combination
Turbo-Bake
Memory
Timer
Start
Stop / Cancel
less
more
NN-CT890S
(1) Display Window
(2) Time Pads
(3) Auto Weight Chaos Defrost
Programs
(4) Auto Sensor Programs
(5) Auto Weight Combination Bake
Programs
(6) Microwave Power Pad
(7) Grill Pad
(8) Convection Pad
(9) Turbo-Bake Pad
(10) Combination Pad
(11) Memory Pad
(12) Timer Pad:
This can be used to delay a
cooking program for up to 9 hrs 59
mins., or used to time or for standing
(non-cooking) time. It is also used for
setting the clock. Refer to page 18.
(13) lb/oz Conversion Pad
(14) More/Less Pads
(15) Start Pad:
Press to start operating the oven.
If during cooking the door is opened
or Stop/Cancel Pad is pressed once,
Start Pad has to be pressed again to
continue cooking.
(16) Stop/Cancel Pad:
Before Cooking:
one press clears your instructions.
During Cooking:
one press temporarily stops the
cooking program. Another press
cancels all your instructions and the
time of day will appear in the display.
(3)
Beep Sound:
A beep sounds when a pad is
pressed. If this beep does not
sound, the setting is incorrect.
When the oven changes from one
function to another, two beeps
sound. After completion of cook-
ing, ve beeps sound.
* The design of your control panel may vary from the panel
displayed (depending on colour and shape of pads or buttons),
but the words relating to the pads will be the same, and
function in the same way.
(1)
(2)
(6)
(9)
(11)
(13)
(15)
(16)
(7)
(8)
(10)
(12)
(14)
(4)
(5)
N.B. If an operation is set and start pad is not pressed, after 6
minutes, the oven will automatically cancel the operation. The
display will revert back to colon or clock mode.

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5 Operation
G
Press Timer Pad twice
Colon starts to blink. “SET TIME”
will appear in the display window.
G
Press Time Pads
Enter time of day by pressing
Time Pads
e.g. 13 pm (24hr clock).
G
Press Timer Pad
Colon stops blinking. Time of day
is now locked into the display.
Press thirteen
times
Setting the Clock
N.B.
1. To reset time of day, repeat steps above.
2. The clock will keep the time of day as long as the oven is plugged in and electricity is supplied.
3. This is a 24 hour clock.
10
min
1
min
10
sec
1
h
Press five times
Press twice
Inoperable
Example of how to set 1.25pm
Timer
Timer
• Select Cooking Time.
• Press this pad until
the power you
require appears in
the display window.
Microwave Cooking and Defrosting
There are 6 different microwave power levels available.
Selecting Microwave Power Level
10
min
1
min
10
sec
1
h
Micro Power
Start
Power
Press Level Wattage
once High 1000 W
twice Defrost 270 W
3 times Medium 600 W
4 times Low 440 W
5 times Simmer 250 W
6 times Warm 100 W
N.B.
1. Maximum time that can be set on HIGH power is 30 min.
2. On all Power Levels, except HIGH power, the maximum time that can be set is 99 minutes,
50 seconds. The 1h pad is inoperable.
• Press Start.
inoperable

NN-CT880MBPQ NN-CT870WBPQ
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10
min
1
min
10
sec
1
h
Grill 1-2-3
Start
Grilling
Start
• Select Grill power.
Press once for Grill 1
(High), twice for Grill 2
(Medium) or three
times for Grill 3 (Low).
The Grill symbol will
appear.
• Press Start to
preheat.
“P” will appear in the
display window. When
the grill is preheated
the oven will beep and
the “P” will flash. Then
open the door and
place the food inside.
• Press Time pads to
enter cooking time.
Maximum time is 99
mins., 50 secs. 1 h
pad is inoperable.
• Press Start.
The cooking program
will start and the time
in the display will
count down.
Always preheat the grill before use.
The metal tray must be on the glass turntable when preheating, unless you are using the enamel
shelf.
Start
Convection Cooking
•
Press to select oven
temperature. The
oven starts at 150 °C
and then for each
press the
temperature will
count up in 10 °C
stages to 250 °C,
then to 40 °C, 100
°C, 110 °C etc. The
Convection symbol
will appear.
•
Press Start to
preheat. A “P” will
appear in the
display window.
When the oven is
preheated the oven
will beep and the “P”
will ash. Then open
the door and place
the food inside. *
•
Press Time Pads to
enter cooking time.
Maximum cooking
time is 9 hours, 59
minutes. The 10 sec
pad is inoperable.
•
Press Start Pad.
10
min
1
min
10
sec
1
h
Start
Convection
The oven will maintain the selected temperature for approximately 30 minutes. If no food has been
placed inside the oven or a cooking time set, then it will automatically cancel the cooking program and
revert to time of day. There is no pre-heat at 40°C.
inoperable

NN-CT880MBPQ NN-CT870WBPQ
7
TURBO-BAKE Cooking
The oven can be programmed to cook or reheat food by the grill and the convection oven working
simultaneously, to give foods that extra crispness and colour. This is known as TURBO-BAKE and can
often reduce traditional oven cooking times.
ALWAYS PREHEAT BEFORE USE .
The Metal Tray must be on the Glass Turntable when preheating, unless you are using the enamel
shelf on the lower level. If using enamel shelf, remove glass turntable and roller ring.
Grill 1-2-3
Start
Turbo-Bake
• Press to select oven
temperature. The oven starts
at 150°C, and then for each
press the temperature will
count up in 10°C stages to
250°C, then to 100°C, 110°C
etc. Grill and Convection
symbols will appear.
• Press to select Grill power, if
you wish to adjust from Grill 3
(Low) to select Grill 1 (High),
or Grill 2 (Medium).
• Press Start to preheat. “P” will
appear in the display window.
When the oven is preheated
the oven will beep and the “P”
will ash. Then open the door
and place the food inside.*
10
min
1
min
10
sec
1
h
Start
• Press Time Pads to enter cooking time.
Maximum time is 9 hours, 59 minutes. The 10
sec. pad is inoperable.
• Press Start.
Combination Cooking
•
Press Combination
pad.
•
Select rst
cooking mode.
•
Select microwave
power. Options
available depend on
rst cooking mode
selected.
•
Press if preheating. *
•
Set cooking time. 10 sec. pad
is inoperable.
•
Press Start pad.
Start
Combination
Grill 1-2-3
Micro Power
or
or
PREHEAT IF NECESSARY
Convection
Turbo-Bake
10
min
1
min
10
sec
1
h
Start
inoperable

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Combination 1. Convection and Microwave
This is the most popular combination mode combining convection heat with microwave power.
Casseroles, meat joints, jacket potatoes and pastries are very successful using this combination.
Unsuitable foods are those which contain whisked eggs, meringues, rich fruit cakes, biscuits and
yorkshire puddings.
It is not necessary to preheat except when cooking pastry dishes, to achieve a better result. For pastry
dishes preheat oven to 210°C on Convection so that the oven is hot, and then select the desired
Combination program.
10
min
1
min
10
sec
1
h
Convection
Micro Power
Start
Combination
•Press Combination Pad. •Press to select oven
temperature. The oven starts
at 150°C, and then for each
press the temperature will
count up in 10°C stages to
250°C, then to 100°C, 110°C
etc.
•Press Micro Power Pad to
select Microwave setting.
HIGH & DEFROST are not
available.
•Press to enter required cooking time. 10 sec
pad is inoperable.
•Press Start Pad.
Combination 2. Grill and Microwave
This Combination mode is suitable for foods
which are normally grilled and for reheating
small savoury items.
Do not use this program with less than 200 g
(7 oz) of food.
It is necessary to preheat when using this
Combination mode and food should always be
cooked uncovered.
Grill 1 - HIGH
Grill 2 - MEDIUM
Grill 3 - LOW
To Preheat Grill
Grill 1-2-3 Micro Power
Start
Combination
• Press Combination
Pad.
•
Select Grill Power.
Press once for Grill 1
(High), twice for Grill 2
(Medium) or three
times for Grill 3 (Low).
•
Select Microwave
Power. Keep pressing
this pad until the
power you require
appears in the display
window. Options
available depend on
Grill Power selected.
•
Press Start to
preheat. “P” will
appear in display
window. When grill is
preheated “P” will
ash and oven will
beep. Just open the
door and place food
inside. *

NN-CT880MBPQ NN-CT870WBPQ
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10
min
1
min
10
sec
1
h
Start
• Press to enter required cooking time.
10 sec. pad is inoperable.
• Press Start Pad.
inoperable
Combination 3. TURBO-BAKE and Microwave
This Combination mode is very useful for foods which require quick browning or crisping.
Unsuitable foods are casseroles, cakes, meringues, pastries with sweet fillings, foods
containing whisked eggs and yorkshire puddings.
It is not necessary to preheat and food should always be cooked uncovered.
10
min
1
min
10
sec
1
h
Turbo-Bake
Grill 1-2-3
Micro Power
Start
Combination
•Press Combination
Pad.
•Press to select oven
temperature. The
oven starts at 150°C,
and then for each
press the temperature
will count up in 10°C
stages to 250°C, then
to 100°C, 110°C etc.
•Press to select Grill
Power, if you wish to
adjust from Grill 3
(Low) to Grill 1 (High)
or Grill 2 (Medium).
•Press to select
Microwave Power.
The options available
will depend on the
other cooking modes
previously selected.
•Press to enter required
cooking time. The 10 sec.
pad is inoperable.
•Press Start Pad.

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8 Description of Operating instruction
8.1. Variable power cooking control
The HIGH VOLTAGE INVERTER POWER SUPPLY controls
the output power by a signal from the digital Programmer circuit
DPC. The power relay (RY1) turns on to supply power to the
inverter circuit. The level of output power is controlled by the
drive signal level from the inverter circuit.
NOTE1: The ON/OFF time ratio does not correspond with
the percentage of microwave power since approximately 2
seconds are required for heating the magnetron filament.
NOTE: 2 If microwave cooking is over 8 minutes on HIGH
power, the fan motor rotates for 1 minute after cooking to
cool the oven and electrical components.
Duty cycles for microwave cooking
8.2. Grill Cooking
The digital programmer circuit controls the grill power by oper-
ating the power relay RY4 in the sequence shown in the table
below
Duty cycles for Grill Cooking
8.3. Auto weight defrost, Auto
weight Cook
When an auto control feature is selected and the start pad
pressed:
1. The digital programmer circuit determines the power level
and the cooking time and indicates the operating state in
the display. The table shows the corresponding cooking
times for each category and its respective weight.
2. When the cooking time in the display window has
elapsed, the oven turns off automatically via the control
signal from the digital programmer circuit.
Note: After auto cooking if the oven temperature is
over the predetermined temperature the fan motor
rotates to cool the oven and its components.
Defrost Menu’s
Weight Menu’s
Output Duty ON/OFF
ON time OFF time
High 1000W 22” 0”
Defrost 440W 16” 6”
Medium 600W 22” 0”
Low 440W 22” 0”
Simmer 440W 15” 7”
Warm 440W 8” 14”
Duty ON/OFF
ON Time OFF Time
Grill 1 66” 0”
Grill 2 54” 12”
Grill 3 42” 24”
Category 1st Touch Weight Cooking Time
Turbo Defrost 500g 8m 20s
Category 1st Touch Weight Cooking Time
1. Whole Chicken 1000g 18m 20s
2. Chicken Pieces with
skin & bone
300g 7m 30s

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8.4. Convection Cooking
1. The digital programmer circuit operates the power relays
RY3,RY5 and RY6 in the sequence as shown in the figure
below.
2. When the oven reaches a predetermined temperature the
digital programmer circuit stops supplying power to relay
RY5, resulting in the convection heater turning off.
3. When the temperature drops below the predetermined
temperature, the digital programmer circuit supplies
power to power relay RY5 resulting in the convection
heater turning on.
Note: After the convection process, if the oven tempera-
ture is higher than the predetermined temperature, the
fan motor rotates to cool the electronic components and
the oven.
Convection Cooking Duty Cycles
Figure 1

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8.5. Combination Cooking
Combination cooking is achieved by operating the microwave
and heater modes together during one cooking cycle. There
are three combination modes.
1. Combination (convection and microwave)
2. Combination (grill and microwave)
3. Combination (grill, convection and microwave)
The digital programmer circuit operates the power relays as
shown in the figures below.
When the oven temperature reaches the predetermined tem-
perature, the digital programmer circuit stops supplying power
to relay (RY5) resulting in the convection heater turning off.
During this time the digital programmer circuit continues to
operate relay (RY1) so that microwave activity continues at the
duty cycle selected. The inverter control signal level is also
maintained. The microwave activity continues to cycle until the
entire cooking program is completed.
When the oven temperature drops below the selected tempera-
ture, the digital programmer circuit operates power relay (RY5)
switching on the heater elements.
In the case of grill combination the sequence applies with the
digital programmer circuit switching power relay (RY4) to con-
trol, the grill elements.
With convection, grill and micro power combination. The grill
elements and convection elements are operated alternatively
whilst the oven temperature is above the selected level.
< Convection + Microwave Combination >
Convection Heater Microwave
ON time OFF time Output [W] Duty (ON /OFF)
Oven Temp 100 - 200 C $66" 0" ON time OFF time
Oven Temp 210 - 250 C $66" 0" Medium 600W $66" 0"
Low 440W $66" 0"
Simmer 440W $45" 21"
Warm 440W $24" 42"
< Grill + Microwave Combination >
Grill Heater Microwave
ON time OFF time Output [W] Duty (ON /OFF)
Grill 1 54" $12" ON time OFF time
Grill 2 42" $24" Medium 600W $66" 0"
Grill 3 34" $32" Low 440W $66" 0"
Simmer 440W $45" 21"
Warm 440W $24" 42"
< Grill Convection + Microwave Combination >
Convection Heater Grill Heater Microwave
ON time OFF time ON time OFF time Output [W] Duty (ON /OFF)
Oven Temp 100 - 200 C $Grill OFF Grill ON Grill 1 54" $12" ON time OFF time
Oven Temp 210 - 250 C $Grill OFF Grill ON Grill 2 42" $24" Medium 600W $66" 0"
Grill 3 34" $32" Low 440W $66" 0"
Simmer 440W $45" 21"
Warm 440W $24" 42"
Convection And Microwave Combination Duty Cycles
Grill And Microwave Combination Duty Cycles
Grill Convection And Microwave Combination Duty Cycles

NN-CT880MBPQ NN-CT870WBPQ
15
8.5.1 convection and microwave duty cycles
Figure 1

NN-CT880MBPQ NN-CT870WBPQ
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8.5.2 grill and microwave duty cycles
Figure 2

NN-CT880MBPQ NN-CT870WBPQ
17
Figure 3
8.5.3 Grill,Convection and microwave duty cycles
Auto sensor cook is a revolutionary way to cook by microwave
without setting a power level or selecting a time. All that is
necessary is to select an auto sensor program before
starting to cook.
Understanding Auto sensor cooking
As food cooks, a certain amount of steam is produced. If the
food is covered, this steam builds up and eventually escapes
from the container. In auto sensor cooking, a carefully designed
instrument, called the humidity sensor element, senses the
escape of steam. then, based upon the auto sensor program
selected, the unit will automatically determine the correct power
level and the proper length of time it will take to cook the food.
NOTE: Auto sensor cooking is successful with the foods and recipes found in the auto sensor cooking guide. Because of
the vast differences in food composition, items not mentioned in the cooking guide should be prepared in the microwave
oven using the power select and time features. Please consult variable power microwave cook book for procedures.
8.6 One touch Auto sensor cooking

NN-CT880MBPQ NN-CT870WBPQ
18
9 Cautions to Be Observed When Troubleshooting
Unlike many other appliances, the microwave oven is a high
voltage, high current device. Although it is free from danger in
ordinary use, extreme care should be taken during repair.
Caution
Servicemen should remove their watches whenever
working close to or replacing the magnetron.
9.1. Check the grounding
Do not operate on a two wire extension cord. The microwave
oven is designed to be used when grounded. It is imperative,
therefore, to ensure the appliance is properly grounded before
beginning repair work.
9.2. Inverter Warnings
DANGER, HIGH VOLTAGE AND HIGH TEMPERATURE
(HOT/LINE) OF THE INVERTER POWER SUPPLY (U)
This high voltage inverter power supply handles very high
voltage and very high current for the magnetron tube.
Though it is free from danger in ordinary use, extreme care
should be taken during repair. As you can see, it looks like a
TV flyback transformer, however, the current is extremely
large and is therefore, dangerous due to this high current
and high voltage.
The aluminium heat sink is also energized with high voltage
(HOT), so do not touch when the AC input terminal is con-
nected. The power devices (Collector) is directly connected
to the aluminium heat sink.
The aluminium heat sink may be (HOT) due to heat energy,
therefore, extreme care should be taken during servicing.
WARNING FOR INVERTER POWER SUPPLY (U) GROUND-
ING
Check the high voltage inverter power supply circuit ground-
ing. This high voltage inverter power supply circuit board
must have a proper chassis ground, the inverter grounding
bracket must be connected to the chassis. If the inverter
board is not grounded it will expose very high voltages and
cause extreme DANGER! Be sure that the inverter circuit is
properly grounded via the inverter earth bracket.
HV Inverter warning
Figure 1

NN-CT880MBPQ NN-CT870WBPQ
19
WARNING!
DISCHARGE THE HIGH VOLTAGE CAPACITORS
For about 30 seconds after the oven is turned off, an elec-
tric charge remains in the high voltage capacitors in the
inverter power supply circuit board.
When replacing or checking parts, remove the power plug
from the outlet and short the inverter output terminal of the
magnetron filament terminals to the chassis ground with an
insulated handle screwdriver to discharge. Please be sure
to touch the chassis ground side first and then short to the
output terminals.
WARNING
There is high voltage present with high current capabilities
in the circuits of the primary and secondary windings, choke
coil and heat sink of the inverter. It is extremely dangerous
to work on or near these circuits with the oven energized.
DO NOT measure the voltage in the high voltage circuit
including the filament voltage of the magnetron.
WARNING
Never touch any circuit wiring with your hand nor with an
insulated tool during operation.
Inverter Grounding
Figure 2
Discharging the high voltage capacitors
Figure 3

NN-CT880MBPQ NN-CT870WBPQ
20
9.3. When parts must be replaced,
remove the power plug from
the outlet.
9.4. When the 10A fuse is blown
due to the operation of the
short switch:
WARNING
When the 10A 250V fuse is blown due to the operation of
the short switch, the primary latch switch and short switch
must be replaced. It is also important to change the power
relay 1 (RY1) when the continuity test shows shorted con-
tacts.
1. This is mandatory. Refer to “adjustments and measure-
ments” for the location of these switches.
2. When replacing the fuse, confirm that it has the appropri-
ate rating for these models.
3. When replacing faulty switches, be sure the mounting
tabs are not bent, broken or deficient in their ability to hold
the switches.
9.5. Avoid inserting nails, wire etc.
through any holes in the unit
during operation.
Never insert a wire, nail or any other metal object through the
lamp holes on the cavity or any holes or gaps, because such
objects may work as an antenna and cause microwave leak-
age.
9.6. Confirm after repair
1. After repair or replacement of parts, make sure that the
screws of the oven, etc. are neither loose nor missing.
Microwaves might leak if screws are not properly tight-
ened.
2. Make sure that all electrical connections are tight before
inserting the plug into the wall outlet.
3. Check for microwave energy leakage. (Refer to proce-
dure for measuring microwave energy leakage).
CAUTION MICROWAVE RADIATION
DO NOT BECOME EXPOSED TO RADIATION FROM THE
MICROWAVE GENERATOR OR OTHER PARTS CON-
DUCTING MICROWAVE ENERGY
IMPORTANT NOTICE
The following components have potentials above 250V
while the appliance is in operation.
• Magnetron
• High voltage transformer (Located on inverter (U))
• High voltage diodes (Located on inverter (U))
• High voltage capacitors (Located on inverter (U))
Pay special attention in these areas.
When the appliance is operated with the door hinges or
magnetron fixed incorrectly, the microwave leakage can
reach more than 5mW/cm3. After repair or exchange, it is
very important to check if the magnetron and the door
hinges are correctly fixed.
9.7. Sharp Edges
Caution
Please use caution when unpacking, installing or moving
the unit, as some exposed edges may be sharp to touch
and cause injury if not handled with care.

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21
10 Parts Replacement Procedure
10.1. Magnetron
1. Discharge the high voltage capacitors on the inverter cir-
cuit.
2. Remove the five screws shown in figure 1
3. Disconnect the two high voltage leads from the magne-
tron
4. Remove the four screws holding the magnetron as shown
in figure 2
NOTE: After replacing the magnetron, tighten the mount-
ing screws making sure that there is no gap between the
waveguide and the magnetron to prevent microwave leak-
age.
Caution
When replacing the magnetron, ensure that the antenna
gasket is in place.
Note
The magnetron used for this model is unique for the inverter
power supply system. Make sure to use the magnetron as
listed in the parts list.
Removal of the magnetron
Figure 1

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22
10.2. Inverter power supply (U)
1. Discharge the high voltage capacitors
2. Unplug the H.V. Lead wires from the magnetron
3. Remove the connector CN701 and CN702 from the
inverter PCB
4. Remove the two screws holding the inverter base to the
chassis (See figure 3)
5. Remove the one screw holding the inverter earth wire to
the oven chassis.
6. Carefully remove the inverter PCB and support base from
the oven.
7. Remove the air guide E by un-clipping the catch hooks
8. Remove the four screws holding the PCB to the inverter
support base.
Caution when replacing the inverter power supply (U)
1. Make sure that grounding plate is in place
2. Securely tighten the grounding screw through the side of
the chassis (Base).
3. Securely connect the 3 lead wire connectors
4. Make sure that the heat sink has enough space (gap)
from the oven. Take care not to touch any lead wire to the
aluminium heat sink because it is hot.
Removal of the inverter PCB
Figure 3
Screws to remove the magnetron
Figure 2