Sharp R9h56 Service Manual

							R-9H56
19 TEST PROCEDURES (CONTD)
PROCEDURE
LETTERCOMPONENT TEST
RY413
(J1)
31
CN-A
M
1
357 9  
DAMP
M
CONV MFAN
POWER P S1 S2
T1
ba
c VRS1
d
Problem: POWER ON, indicator does not
light up.
NOTE: *At the time of making these repairs,
make a visual inspection of the
varistor. check for burned  damage
and examine the transformer with an
ohmmeter for the presence of layer
short-circuit (check primary coil
resistance). If any abnormal condition
is detected, replace the defective
parts.
PAH SENSOR TEST
Checking the initial sensor cooking condition
(1) The oven should be plugged in at least five minutes before sensor cooking.
(2) Room temperature should not exceed 35ûC.
(3) The unit should not be installed in any area where heat and steam are generated. The unit should
not be installed, for example, next to a conventional surface unit. Refer to the INSTALLATION
Instructions .
(4) Exhaust vents are provided on the back of the unit for proper cooling and air flow in the cavity. To
permit adequate ventilation, be sure to install so as not to block these vents. There should be some
space for air circulation.
(5) Be sure the exterior of the cooking container and the interior of the oven are dry. Wipe off any moisture
with a dry cloth or paper towel.
(6) The Sensor works with food at normal storage temperature.For example, chicken pieces would be
at refrigerator temperature and canned soup at room temperature.
(7) Avoid using aerosol sprays or cleaning solvents near the oven while using Sensor settings. The
sensor will detect the vapor given of by the spray and turn off before food is properly cooked.
(8) After the oven is started on sensor cooking condition, if the sensor has not detected the vapor of the
food, ERROR will appear and the oven will shut off.
Water load cooking test
Make sure the oven has been plugged in at least five minutes before checking sensor cook operation.
The cabinet should be installed and screws tightened.
(1) Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup.
(2) Place the container on the center of tray in the oven cavity.
(3) Close the door.
(4) Touch REHEAT SENSOR pad twice. Now, the oven is in the sensor cooking condition and MENU2
will appear in the display.
(5) The oven will operate for the first 16 seconds, without generating microwave energy.
When the AH sensor is defective (open or short), ERROR will appear in the display after 16 seconds
cleaning time.
If ERROR appears check sensor wire connections and/or AH sensor.
NOTE: ERROR will appear if the door is opend or STOP/CLEAR pad is touched during first stage of
sensor cooking.
(6) After approximately 16 seconds, microwave energy is produced, oven should turn off after water is
boiling (bubling).
If the oven does not turn off, replace the AH sensor or check the control unit, refer to explanation below.
TESTING METHOD FOR AH SENSOR AND/OR CONTROL UNIT
To determine if the sensor is defective, the simplest method is to replace it with a new replacement
sensor.
(1) Disconnect oven from power supply and remove outer case.
(2) Discharge the high voltage capacitor. 
						

							R-9H56
20
(3) Remove the AH sensor.
(4) Install the new AH sensor.
(5) Re-install the outer case.
(6) Reconnect the oven to the power supply and check the sensor cook operation, proceed as follows:
6-1. Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup.
6-2. Place the container on the center of tray in the oven cavity.
6-3. Close the door.
6-4. Touch REHEAT SENSOR pad twice.
6-5. The control panel is in automatic Sensor operation.
6-6. The oven will turn off automatically after the water is boiling (bubling).
If new sensor dose not operate properly, the problem is with the control unit.
CHECKING CONTROL UNIT
(1) Disconnect oven from power supply and remove outer case.
(2) Discharge the high voltage capacitor.
(3) Disconnect the wire leads from the cook relay.
(4) Disconnect the sensor connector that is mounted to lower portion of control panel.
(5) Then connect the dummy resistor circuit (see fig.) to the sensor connector of control panel.
(6) Reconnect the oven to the power supply and check the sensor cook operation, proceed as follows:
6-1. Touch REHEAT SENSOR pad twice.
6-2. The control panel is in the sensor cooking operation.
6-3. After approximately 20 seconds, push plunger of select switch. This condition is same as
       judgement by AH sensor.
6-4. After approximately 3 seconds, cooking operation turns off, an audible signal will sound,
and the display will then revert to the time of day.
If the above is not the case, the control unit is probably defective.
If the above is proper, the AH sensor is probably defective.
R1,R2 :  100W ± 1% 1/2W
   R3 :   10kW ± 5% 1/4W
   R4 :    3kW ± 5% 1/4W
TEST PROCEDURES (CONTD)
PROCEDURE
LETTERCOMPONENT TEST
Plunger
NC
NO
COM
COMNO
NC
R3 R4 R1
R2 1
2
3 F-1
F-2
F-3To connector (F)
on Control Unit.
CONNECTOR
Sensor Dummy Resistor Circuit 
						

							R-9H56
21
4) ACL Circuit
A circuit to generate a signals which resetting the LSI to
the initial state when power is applied.
5) Buzzer Circuit
The buzzer is responds to signals from the LSI to emit
noticing sounds (key touch sound and completion sound).
6) Temperature Measurement Circuit: Oven
The temperature in the oven cavity is sensed by the
thermistor. The variation of resistance according to
sensed temperature is detected by the temperature
measurement circuit and the result applied to LSI. The
LSI uses this information to control the relay and display
units.
7) Absolute Humidity Sensor Circuit
This circuit detects the humidity of a food which is being
cooked, to control its automatic cooking.
8) Door Sensing Switch
A switch to inform the LSI if the door is open or closed.
9) Relay Circuit
To drive the magnetron, heating element, fan motor,
convection motor, damper motor, turntable motor and
light the oven lamp.
10) Indicator Circuit
Indicator element is a Fluorescent Display.
Basically, a Fluorescent Display is triode having a
cathode, a grid and an anode. Usually, the cathode of a
Fluorescent Display is directly heated and the filament
serves as cathode.
The Fluorescent Display has 6-digits, 15-segments are
used for displaying figures. The touch control section consists of the following units
as shown in the touch control panel circuit.
(1) Key Unit
(2) Control Unit
The principal functions of these units and the signals com-
municated among them are explained below.
Key Unit
The key unit is composed of a matrix, signals generated in
the LSI are sent to the key unit through P03, P05, P11, P12,
P15, P16, P20 and P23. When a key pad is touched, a signal
is completed through the key unit and passed back to the
LSI through R24-R27 to perform the function that was
requested.
Control Unit
Control unit consists of LSI, power source circuit, synchro-
nizing signal circuit, ACL circuit, buzzer circuit, temperature
measurement circuit, absolute humidity sensor circuit and
indicator circuit.
1) LSI
This LSI controls the temperature measurement signal,
AH sensor signal, key strobe signal, relay driving signal
for oven function and indicator signal.
2) Power Source Circuit
This circuit generates the voltage necessary for the
control unit from the AC line voltage.
3) Synchronizing Signal Circuit
The power source synchronizing signal is available in
order to compose a basic standard time in the clock
circuit. It incorporates a very small error because it works
on commercial frequency.
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL 
						

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1 VCC IN Connected to GND.
2 VEE IN
Anode (segment) of Fluorescent Display light-up voltage: -28V.
Vp voltage of power source circuit input.
3 AVSS IN
Power source voltage: -5V.
VC voltage of power source circuit input.
4 VREF IN
Reference voltage input terminal.
A reference voltage applied to the A/D converter in the LSI. Connected to GND.(0V)
5 AN7 IN Used for initial balancing of the bridge circuit (absolute humidity sensor). This input is
an analog input terminal from the AH sensor circuit, and connected to the A/D coverter
built into the LSI.
6 AN6 IN
AH sensor input.
This input is an analog input terminal from the AH sensor circuit, and connected to the
A/D converter built into the LSI.
7-9 AN5-AN3 INHeating constant compensation terminal.
10 AN2 IN
Input signal which communicates the damper open/close information to LSI.
Damper opened; H level signal(0V:GND).
Damper closed; L level signal(-5V).
11 AN1 IN
Input signal which communicates the door open/close information to LSI.
Door closed; H level signal(0V).
Door opened; L level signal(-5V).
12 AN0 IN
Temperature measurement input: OVEN THERMISTOR.
By inputting DC voltage corresponding to the temperature detected by the thermistor,
this input is converted into temperature by the A/D converter built into the LSI.
13 P55 OUT
Magnetron high-voltage circuit driving signal.
To turn on and off the cook
relay(RY2). In HIGH operation, the
signals holds L level during micro-
wave cooking and H level while
not cooking. In other cooking modes
(MED HIGH, MED, MED LOW,
LOW) the signal turns to H level
and L level in repetition according
to the power level.
14 P54 OUT
Heating element driving signal.
To turn on and off shut-off relay(RY3). L level during
convection cooking; H level otherwise. During con-
vection cooking, the signal becomes H level when the
temperature of the oven cavity exceeds the predeter-
mined temperature.
15 P53 OUT
Cooling fan motor driving signal.
To turn on and off shut-off relay(RY6). L level
during both microwave and convection cooking;
H level otherwise.
16 P52 OUT
Convection motor driving signal.
To turn on and off shut-off relay(RY5). L level
during CONVECTION; H level otherwise.
17 P51 OUT
Damper motor relay driving signal.
To turn on and off shut-off relay(RY4).
18 P50 OUT Terminal not used.
19 P47 OUTOven lamp and turntable motor driving signal. (Square Waveform : 50Hz)
To turn on and off the shut-off  relay(RY1).
DESCRIPTION OF LSI
LSI(IZA589DR):
The I/O signals of the LSI(IZA589DR) are detailed in the following table.
Pin No. Signal I/O Description
VARI MODE ON TIME OFF TIME
HIGH (100% power) 32 sec. 0 sec.
MED HIGH (approx. 70% power) 24 sec. 8 sec.
MED (approx. 50% power) 18 sec. 14sec.
MED LOW (approx. 30% power) 12 sec. 20 sec.
LOW (approx. 10% power) 6 sec. 26 sec.
ONOFF During
cooking
LGND H.(Convection)
ONOFF
During
cooking
LGND
H.
ONOFF During
cooking
LGND H.(Convection)
ONOFFH : GND
L 
						

							R-9H56
23
The square waveform voltage is delivered
to the relay(RY1) driving circuit and
relays(RY2,RY3,RY5) control circuit.
20-21 P46-P45 OUT Terminal not used.
22 P44 OUT
Timing signal output terminal for temperature measurement(OVEN).
H level (GND) : Ttermistor OPEN timing.
L level (-5V) : Temperature measuring timing.(Convection cooking)
23 P43 OUT
Signal to sound buzzer.
A: key touch sound.
B: Completion sound.
C: When the temperature of the oven cav-
ity reaches the preset temperature in
the preheating mode, or when the
preheating hold time (30 minutes) is
elapsed.
24 P42 OUT
Timing signal output terminal for temperature measurement(OVEN).
H level (GND) : Ttermistor OPEN timing.
L level (-5V) : Temperature measuring timing.(Convection cooking)
25 P41 IN
Signal to synchronize LSI with commercial power source freqency.
This is the basic timing for all real time
processing of LSI.
26 P40 IN Connected to GND.
27 RST IN
Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is applied.  Temporarily
set to L level the moment power is applied, at this time the LSI is reset. Thereafter
set at H level.
28/29XCIN/XCOUTOUT Terminal not used.
30 XIN IN
Internal clock oscillation frequency setting input.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit with
respect to XOUT terminal.
31 XOUT OUT
Internal clock oscillation frequency control output.
Output to control oscillation input of XIN.
32 VSS IN
Power source voltage: -5V.
VC voltage of power source circuit input.
33 P27 IN
Signal coming from touch key.
When any one of G-1 line keys on key matrix is touched, a corresponding signal from
P03,P05,P11,P12,P15,P16,P20 and P23 will be input into P27. When no key is
touched, the signal is held at L level.
34 P26 IN
Signal similar to P27.
When any one of G-2 line key on key matrix is touched, a corresponding signal will be
input into P26.
35 P25 IN
Signal similar to P27.
When any one of G-3 line key on key matrix is touched, a corresponding signal will be
input into P25.
36 P24 IN
Signal similar to P27.
When any one of G-4 line key on key matrix is touched, a corresponding signal will be
input into P24.
37 P23 OUT
Segment data signals.
The relation between signals and indicators are as follows:
SignalSegmentSignalSegmentSignalSegmentSignalSegment
P35 ........... P1 P03 ........ P5 P12 ......... P8 P20 ....... P13
P36 ......... P2 P04 .......... P6 P13 ............ P9 P21 ........... P14
P00 .......... P3 P05 ............. P7 P15 ........... P10 P23 ........... P15
P01 ............ P4 P11 ........... P12 P16 ........... P11
Pin No. Signal I/O Description
During cookingL
H20 msec.
A
B
C
H: GND
L 0.1 sec
2 sec
1 sec
1 sec
H : GND
L (-5V)
20 msec 
						

							R-9H56
24
Pin No. Signal I/O Description
Key strobe signal.
Signal applied to touch-key section. A pulse
signal is input to P24-P27 terminal  while one of
G-5 line keys on key matrix is touched.
38 P22 OUT
Digit selection signal.
The relationship between digit signal and digit are as follows;
Digit signalDigit
P22 ............. 1st.
P17 .......... 2nd.
P14 .......... 3rd.
P06 ........... 4th.
P02 .......... 5th.
P37 ..........  6th.
Normally, one pulse is output in every §
period, and input to the grid of the Fluores-
cent Display.
39 P21 OUT
Segment data signal.Signal similar to P23.
40 P20 OUTSegment data signal.Signal similar to P23.
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P24-P27 terminal  while
one of G-6 line keys on key matrix is touched.
41 P17 OUT
Digit selection signal.Signal similar to P22.
42 P16 OUTSegment data signal.Signal similar to P23.
Signal similar to P23.
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P24-P27 terminal  while
one of G-7 line keys on key matrix is touched.
43 P15 OUT
Segment data signal.
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P24-P27 terminal  while
one of G-8 line keys on key matrix is touched.
44 P14 OUT
Digit selection signal.Signal similar to P22.
45 P13 OUTSegment data signal.Signal similar to P23.
46 P12 OUTSegment data signal.Signal similar to P23.
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P24-P27 terminal  while
one of G-9 line keys on key matrix is touched.
47 P11 OUT
Segment data signal.Signal similar to P23.
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P24-P27 terminal  while
one of G-10 line keys on key matrix is touched.
48/49 P10/P07 OUT Terminal not used.
50 P06 OUT
Digit selection signal.Signal similar to P22.
51 P05 OUTSegment data signal.Signal similar to P23.
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P24-P27 terminal  while
one of G-11 line keys on key matrix is touched.
52 P04 OUT
Segment data signal.Signal similar to P23.
ß(50Hz)
GND
VP
P22 ß(50Hz)H
L
GND
VP
P17
P14
P06
P02
P37 
						

							R-9H56
25
Pin No. Signal I/O Description
53 P03 OUT
Segment data signal.Signal similar to P23.
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P24-P27 terminal  while
one of G-12 line keys on key matrix is touched.
54 P02 OUT
Digit selection signal.Signal similar to P22.
55-56 P01-P00 OUTSegment data signal.Signal similar to P23.
57 P37 OUTDigit selection signal.Signal similar to P22.
58-59 P36-P35 OUTSegment data signal.Signal similar to P23.
60-64 P34-P30 OUT Used for initial balancing of the bridge circuit (absolute humidity sensor).
SW1
SW2
SW3
SW4
SW5P30
P31
P32
P33
P34
 LSI
(IC1)
AN7
AN6
620k
300k
150k
75k
37.4k
464
563
6
7
862
61
60
35
26
47k 47k
10k
0.01uF0.015uF0.01uF
360k
+
-
1
12
VA : -15V
VA : -15V
R519
S
F-2
101.8k
F-1
F-3C11
3.57k
3.32k
VC : -5V
0.1
uF
C. Thermistor in 
    closed vesssl
S. Thermistor in
   open vessel
IC2(IZA495DR)
C
S
R3R1
R2+
- Operational
amplifier
Output
voltage
S : Thermistor
    open vessel
C : Thermistor
    closed vessel
2Absolute humidity (g/m  )
Output voltage
Absolute humidity vs,
output voltage characterist
LSI are turned on in such a way as to change the
resistance values in  parallel with R50-1.  Changing the
resistance values results in that there is the same
potential at both F-3 terminal of the absolute humidity
sensor and AN7 terminal of the LSI.  The voltage of AN6
terminal will indicate about -2.5V.  This initial balancing
is set up about 16 seconds after the unit is put in the
Sensor Cooking mode.  As the sensor cooking proceeds,
the food is heated to generate moisture by which the
resistance balance of the bridge circuit is deviated to
increase the voltage available at AN6 terminal of the LSI.
Then the LSI observes that voltage at AN6 terminal and
compares it with its initial value, and when the comparison
rate reaches the preset value (fixed for each menu to be
cooked), the LSI causes the unit to stop sensor cooking;
thereafter, the unit goes in the next operation
automatically.
When the LSI starts to detect the initial voltage at AN6
terminal 16 seconds after the unit has been put in the
Sensor Cooking mode, if it is not possible to balance, of
the bridge circuit due to disconnection of the absolute
humidity sensor, ERROR will appear on the display and
the cooking is stopped.
1) Absolute humidity sensor circuit (1) Structure of Absolute Humidity Sensor
The absolute humidity sensor includes two thermistors
as shown in the illustration. One thermistor is housed in
the closed vessel filled with dry air while another in the
open vessel. Each sensor is provided with the protective
cover made of metal mesh to be protected from the
external airflow.
(2) Operational Principle of Absolute Humidity Sensor
The figure below shows the basic structure of an absolute
humidity sensor. A bridge circuit is formed by two
thermistors and two resistors (R1 and  R2).
The output of the bridge circuit is to be amplified by the
operational amplifier.
Each thermistor is supplied with a current to keep it
heated at about 150ûC, the resultant heat is dissipated in
the air and if the two thermistors are placed in different
humidity conditions they show different degrees of heat
conductivity leading to a potential difference between
them causing an output voltage from the bridge circuit,
the intensity of which is increased as the absolute
humidity of the air increases.  Since the output is very
minute, it is amplified by the operational amplifier.
(3) Detector Circuit of Absolute Humidity Sensor Circuit
This detector circuit is used to detect the output voltage
of the absolute humidity circuit to allow the LSI to control
sensor cooking of the unit.  When the unit is set in the
sensor cooking mode, 16 seconds clearing cycle occurs
than the detector circuit starts to function and the LSI
observes the initial voltage available at its AN6 terminal.
With this voltage given, the switches SW1 to SW5 in the
ABSOLUTE HUMIDITY SENSOR CIRCUIT
Sensing part
(Open vessel)Sensing part
(Closed vessel) 
						

							R-9H56
26
1. Precautions for Handling Electronic Components
This unit uses CMOS LSI in the integral part of the
circuits. When handling these parts, the following
precautions should be strictly followed. CMOS LSI have
extremely high impedance at its input and output
terminals. For this reason, it is easily influenced by the
surrounding high voltage power source, static electricity
charge in clothes, etc., and sometimes it is not fully
protected by the built-in protection circuit.
In order to protect CMOS LSI.
1) When storing and transporting, thoroughly wrap them in
aluminium foil. Also wrap all PW boards containing them
in aluminium foil.
2) When soldering, ground the technician as shown in the
figure and use grounded soldering iron and work table.
2. Shapes of Electronic Components
3. Servicing of Touch Control Panel
We describe the procedures to permit servicing of the
touch control panel of the microwave oven and the
precautions you must take when doing so. To perform
the servicing, power to the touch control panel is available
either from the power line of the oven itself or from an
external power source.
(1) Servicing the touch control panel with power supply
of the oven:
CAUTION:
THE HIGH VOLTAGE TRANSFORMER OF THE
MICROWAVE OVEN IS STILL LIVE DURING
SERVICING PRESENTS A HAZARD.
Therefore, when checking the performance of the touch
control panel, put the outer cabinet on the oven to avoid
touching the high voltage transformer, or unplug the
primary terminal (connector) of the high voltage
transformer to turn it off; the end of such connector must
be insulated with an insulating tape. After servicing, be
sure to replace the leads to their original locations.
A.On some models, the power supply cord between the
touch control panel and the oven itself is so short that the
two cant be separated.
SERVICING
For those models, check and repair all the controls
(sensor-related ones included) of the touch control panel
while keeping it connected to the oven.
B.On some models, the power supply cord between the
touch control panel and the oven proper is long enough
that they may be separated from each other. For those
models, therefore, it is possible to check and repair the
controls of the touch control panel while keeping it apart
from the oven proper; in this case you must short both
ends of the door sensing switch (on PWB) of the touch
control panel with a jumper, which brings about an
operational state that is equivalent to the oven door
being closed. As for the sensor-related controls of the
touch control panel, checking them is possible if dummy
resistor(s) with resistance equal to that of the controls
are used.
(2) Servicing the touch control panel with power supply
from an external power source:
Disconnect the touch control panel completely from the
oven proper, and short both ends of the door sensing
switch (on PWB) of the touch control panel, which brings
about an operational state that is equivalent to the oven
door being closed. Connect an external power source to
the power input terminal of the touch control panel, then
it is possible to check and repair the controls of the touch
control panel it is also possible to check the sensor-
related controls of the touch control panel by using the
dummy resistor(s).
4. Servicing Tools
Tools required to service the touch control panel
assembly.
1) Soldering iron: 30W
(It is recommended to use a soldering iron with a grounding
terminal.)
2) Oscilloscope: Single beam, frequency range: DC - 10MHz
type or more advanced model.
3) Others: Hand tools
5. Other Precautions
1) Before turning on the power source of the control unit,
remove the aluminium foil applied for preventing static
electricity.
2) Connect the connector of the key unit to the control unit
being sure that the lead wires are not twisted.
3) After aluminium foil is removed, be careful that abnormal
voltage due to static electricity etc. is not applied to the
input or output terminals.
4) Attach connectors, electrolytic capacitors, etc. to PWB,
making sure that all connections are tight.
5) Be sure to use specified components where high precision
is required.
approx. 1M ohm
ECB
ECBECB
Transistor
2SB793Transistor
DTD143EATransistorDTA114YS
DTA143ES
DTB143ES 
						

							R-9H56
27
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
WARNING: Avoid possible exposure to microwave energy. Please follow the instructions below before
operating the oven.
1. Door does not close firmly.
2. Door hinge, support or latch hook is damaged.
3. The door gasket or seal or damaged.
4. The door is bent or warped.
5. There are defective parts in the door interlock system.
6. There are defective  parts in the microwave generating
and transmission assembly.
7. There is visible damage to the oven.
Do not operate the oven:
1. Without the RF gasket (Magnetron).
2. If the wave guide or oven cavity are not intact.
3. If the door is not closed.
4. If the outer case (cabinet) is not fitted. 1. Disconnect the oven from power supply.
2. Make sure that a definiteÓ clickÓ can be heard when the
microwave oven door is unlatched. (Hold the door in a
closed position with one hand, then push the door open
button with the other, this causes the latch leads to rise,
it is then possible to hear a ÒclickÕ as the door switches
operate.)
3. Visually check the door and cavity face plate for damage
(dents, cracks, signs of arcing etc.).
Carry out any remedial work that is necessary before
operating the oven.
Do not operate the oven if any of the following conditions
exist;
Please refer to ÔOVEN PARTS, CABINET PARTS, DOOR PARTSÕ, when carrying out any of the following removal
procedures:
OUTER CASE REMOVAL
To remove the outer case, proceed as follows.
1. Disconnect the oven from power supply.
2. Open the oven door and wedge it open.
3. Remove the screws from rear and along the side edge of
case.
4. Slide the entire case back about 1 inch (3cm) to free it
from retaining clips on the cavity face plate.
5. Lift the entire case from the oven.6. Discharge the H.V. capacitor before carring out any
further work.
7. Do not operate the oven with the outer case removed.
N.B.; Step1, 2 and 6 from the basis of the 3D checks.
CAUTION: DISCHARGE HIGH VOLTAGE CAPACITOR
BEFORE TOUCHING ANY OVEN COMPO-
NENTS OR WIRING.
REMOVAL
1. CARRY OUT 
3D CHECKS.
2. Disconnect the wire leads from power transformer.
3. Disconnect the filament leads of the power transformer
from the megnetron and high voltage capacitor.
4. Disconnect the high voltage leads of capacitor from  the
transformer.
5. Remove the two (2) screws and one (1) washer holding
the transformer to the base cabinet.
6. Remove the transformer.
RE-INSTALL
1. Rest the transformer on the base cabinet with its primary
terminals toward rear cabinet.
2. Insert the two edges of the transformer into two metal
tabs of the base cabinet.
POWER TRANSFORMER REPLACEMENT
3. Make sure the transformer is mounted correctly to the
corners underneath those tabs.
4. After re-installing the transformer, secure the transformer
with two screws to the bace cabint, one is with outertooth
washer and the other is without outer-tooth washer.
5. Re-connect the wire leads (primary and high voltage)
and high voltage lead to the transformer and filament
leads of transformer to the magnetron and capacitor,
referring to the ÒPictorial DiagramÓ.
6. Re-install the outer case and check that the oven is
operating properly.
NOTE: LIVE(ORANGE) WIRE MUST BE CONNECTED
TO THE CABINET-SIDE OF THE POWER
TRANSFORMER.
1. CARRY OUT 
3D CHECKS
2. Disconnect filament lead of transfomer and high voltage
wire lead from magnetron.
3. Take off three (3) screws secured the chassis support to
oven cavity and waveguide.
4. Remove the cooling fan assembly refer to ÒCooling Fan
RemovalÓ
5. Carefully remove four (4) mounting screws holding the
magnetron and magnetron air guide to waveguide. Whenremoving the screws hold the magnetron and magnetron
air guide to prevent it from falling.
6. Remove the magnetron from the waveguide with care so
the magnetron antenna should not hit by any metal
object around the antenna
CAUTION: WHEN REPLACING THE MAGNETRON, BE
SURE THE R.F. GASKET IS IN PLACE AND
THE MAGNETRON MOUNTING SCREWS
ARE TIGHTENED SECURELY.
MAGNETRON REMOVAL 
						

							R-9H56
28
ASYMMETRIC RECTIFIER AND HIGH VOLTAGE RECTIFIER REMOVAL
1. CARRY OUT 3D CHECKS.
2. Remove one (1) screw holding the high voltage rectifier
terminal to the capacitor holder.
3. Disconnect the high voltage rectifier assembly from the
capacitor.CAUTION: WHEN REPLACING HIGH VOLTAGE RECTI-
FIER ASSEMBLY, ENSURE THAT THE
EARTHING SIDE TERMINAL MUST BE SE-
CURED FIRMLY WITH  AN EARTHING
SCREW.
HIGH VOLTAGE CAPACITOR REMOVAL
1. CARRY OUT 3D CHECKS.
2. Disconnect the high voltage wire leads and rectifier
assembly from the high voltage capacitor and magnetron.
3. Disconnect filament lead of transfomer from high voltage
capacitor.
4. Disconnect high voltage wire leads of capacitor fromtransformer.
5. Remove one (1) screw and washer holding the high
voltage rectifier from the capacitor holder.
6. Remove one (1) screw holding capacitor holder to rear
cabinet.
7. Remove the  high voltage capacitor from the holder.
1. CARRY OUT 
3D CHECKS.
2. Pull the wire leads from the oven lamp socketby pushing
the terminal hole of the oven lamp socket withthe flat type
small screw driver.
3. Lift up the tab of oven lamp mounting plate holding the
oven lamp socket.
4. Slide the oven lamp socket left-ward.
5. Now, the oven lamp socket is free.
CAUTION:WHEN REPLACING THE OVEN LAMP
SOCKET, REPLACE IT SO THAT THE SIDE
WHERE THE BLACK DOT IS PUT FACES
UPWARD.
OVEN LAMP SOCKET REMOVAL
HEATER UNIT ASSEMBLY REMOVAL (HEATING ELEMENT/THERMISTOR)
1. CARRY OUT 3D CHECKS.
2. Disconnect wire leads from oven thermal cut-out,
convection motor, thermistor and heater element.
Remove convection motor assÕy refer to ÒConvection
Motor Removal No.3 to No.5Ó.
3. Remove eleven (11) screws holding heater duct to the
oven cavity.
4. Release two (2) snap bands holding wire harness to the
thermal protection plate (left).
5. The heater unit is now free.HEATING ELEMENT AND THERMISTOR
1. Remove two (2) screws holding heating element to
heater duct.
2. Loosen two (2) screws holding holders to heater duct
and take heating element out of heating element holders.
3. Heating element is free.
4. Remove two (2) screws holding thermistor to heater
duct.
5. Thermistor is free.
Oven lamp
socket
Terminal
Wire lead
Flat type small 
screw driver
Terminal hole
CONTROL PANEL ASSEMBLY AND CONTROL UNIT REMOVAL
To remove the control panel, proceed as follows:
1. CARRY OUT 3D CHECKS
2. Disconnect connector CN-A, CN-E, CN-B, CN-F, TAB1,
TAB2 and TAB3 from the control unit.
3 Remove one (1) screw holding the control panel back
plate to the chassis support.
4. Remove the one (1) screw holding the bottom edge of
the back plate to the cabinet base.
5. Remove two (2) screws holding the back plate to the
oven cavity flange.
6. Lift up and pull the control panel forward.
Replacement of individual component is as follows:
CONTROL UNIT AND KEY UNIT
1. Disconnect the wire connector from the control unit.
2. Remove the four (4) screws holding the panel frame to
the back plate.3. Separate the panel frame and back plate.
4. Remove the three (3) screws holding the control unit to
the panel frame.
5. Lift up the control unit and disconnect the key connector
from the control unit.
6. Now, the control unit and frame assembly are separated.
NOTE: 1.Before attaching a new key unit, remove remaining
adhesive on the control panel frame surfaces
completely with alcohol and so on.
2. When attaching the key unit to the control panel
frame, adjust the lower  edge and right edge of the
key unit to the correct position of  control panel
frame.
3. Stick the key unit firmly to the control panel frame
by rubbing with soft cloth not to scratch.
Black dot