Page 1
SERVICE MANUAL STAINLESS STEEL EM-SL20NECO
MICROWAVE OVEN WITH GRILL
FOREWORD
Read this manual carefully, especially precaution on microwave energy, and follow the procedure
strictly. Careless servicing and testing may expose yourself to the microwave energy leakage.
FILE No.
PRECAUTIONS
PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID
POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY
(a) Do not operate or allow the oven to be operated with the door open.
(b) Make the following safety checks on all ovens to be serviced before activating the magnetron or
other microwave source, and make repairs if necessary:
(1) Interlock operation, (2) proper door closing, (3) seal and sealing surfaces (arcing, wear, and
otherdamage), (4) damage to or loosening of hinges and latches, (5) evidence of dropping or
abuse.
(c) Before turning on microwave power for any service test or inspection within the
microwave generating compartments, check the magnetron, wave-guide or transmission line,
and cavity for proper alignment, integrity, and connections.
(d) Any defective or misadjusted components in the interlock, monitor, door seal, and microwave
generation and transmission systems shall be repaired, replaced, or adjusted by procedures
described in this manual before the oven is released to the owner.
REFERENCE No.
SM-2400005
C
1
5
0
w
4
5
0
w
K
g
/
A
U
T
O
MIN
S
E
C
C
150w 450w
Kg
/
AUTO
MIN
SEC
Product Code No.
EM-SL20NECO 1-437-574-25
Page 2
TABLE OF CONTENTS
Adjustment Procedures........................................1 Circuit Diagram.................................................... 4
Specifications....................................................... 2 Test Procedures and Troubleshooting................. 5-12
Power Output Measurement................................ 2 Disassembly Instructions..................................... 13-14
Precautions and Repair Service Tips...................2 Exploded View and Parts list................................15-19
Oven Control Panel..............................................3 Control Circuit Board............................................20
Overall Circuit Diagrams...................................... 21
1. ADJUSTMENT PROCEDURES
TO AVOID POSSIBLE EXPOSURE TO MICRO-WAVE
ENERGY LEAKAGE, THE FOLLOWING ADJUSTMENT OF THE INTERLOCK SWITCHES SHOULD
BE MADE ONLY BY AUTHORISED SERVICE
PERSONNEL
PRIMARY INTERLOCK SWITCH, DOOR SENSING
SWITCH AND INTERLOCK MONITOR SWITCH
ADJUSTMENT
(Figure 1)
(1) Loosen 2 screws securing the lever stopper.
(2) Adjust the lever stopper position so that it is pushed
up and pull forward until there is about zero gap.
2-1. Between the lever and the switch body on
the door sensing switch.
2-2. Between the lever and the switch body
on the interlock monitor switch.
2-3. Between the latch lever and the switch body
on the primary interlock switch.
when the door latch is securely locked.
(3) Tighten the lever stopper screws securely.
(4) Make sure the interlock monitor is closed after
the primary interlock switch opens when the door is
opened very slowly, according to “CHECKOUT
PROCEDURE FOR SWITCHES” on page 8.
(5) Make sure the interlock monitor is open before
the primary interlock and secondary interlock
switches close when the door is closed very slowly,
according to “CHECKOUT PROCEDURE FOR
SWITCHES” on page 8.
(6) Make sure the microwave energy leakage is below
the limit of the regulation (5mW/cm2) when
measured with a detector. ( All service
adjustments must be made for minimum energy
leakage readings.)
-1-
CAUTION
MICROWAVE ENERGY
PERSONNEL SHOULD NOT BE EXPOSED TO
THE MICROWAVE ENERGY WHICH MAY RADIATE FROM THE MAGNETRON OR OTHER
MICROWAVE GENERATING DEVICE IF IT IS
IMPROPERLY USED OR CONNECTED. ALL
INPUT AND OUTPUT MICROWAVE CONNECTIONS, WAVE GUIDES, FLANGES, AND GASKETS MUST BE SECURE. NEVER OPERATE
THE DEVICE WITHOUT A MICROWAVE ENERGY ABSORBING LOAD ATTACHED. NEVER
LOOK INTO AN OPEN WAVE GUIDE OR
ANTENNA WHILE THE DEVICE IS ENERGISED.
Figure 1
Lever Stopper
Door Sensing
Switch
Interlock Monitor
Switch
Primary Interlock
Switch
Screw
Positions
Latch Lever
Door Latch
Lever
Page 3
2. SPECIFICATIONS - EM-SL20N
Rated Power Consumption........ Micro 1450±10%W
Grill 1100+5/-10%W
Dual 2500+5/-10%W
(After 15mins.)
Microwave Output...................... 900W( Adjustable 90W
through 900W )
Frequency.................................. 2,450MHz ± 50MHz
Power Supply............................. 230V,50Hz
Rated Current.............................Micro 6.3±10% Amps
Grill 4.75+5/-10% Amps
Dual 10.9+5/-10% Amps
(After 15mins.)
Safety Devices........................... Thermal Protector for
Magnetron and Cavity,
Open at 122˚C
Thermal Protector for
Heater, Open at 150˚C
Fuse (Cartridge Type 8A)
Primary Interlock Switch
Door Sensing Switch
Interlock Monitor Switch
Timer.......................................... Electronic Digital
Overall Dimensions.............490(W)x378(D)x322(H)mm
Oven Cavity Size.................304(W)x304(D)x248(H)mm
Turntable Diameter.....................262mm
Net Weight..................................Approx. 19.0Kg.
3. POWER OUTPUT MEASUREMENT
(1) Prepare 1000cc tap water in a wide mouthed Pyrex
container.
(2) Stir thoroughly and note initial water temperature T1
(˚C).
(3) Place container in centre of oven and operate for 60
seconds at full power.
(4) Remove container, stir thoroughly and note final
water temperature T2 (˚C).
(5) Calculate power output= 70 x Temp. rise (T2-T1).
NOTE: This is only an approximate test method, not
IEC705 test method to which the microwave oven has
been tested and rated.
-2-
4.PRECAUTIONS AND REPAIR SERVICE TIPS
PRELIMINARY
A.SINCE NEARLY 4,000 VOLTS EXIST IN
SOME CIRCUITS OF THIS MICROWAVE
OVEN, REPAIRS SHOULD BE CARRIED
OUT WITH GREAT CARE
B.TO AVOID POSSIBLE EXPOSURE TO
MICROWAVE ENERGY LEAKAGE, THE
FOLLOWING PRECAUTIONS MUST BE
TAKEN BEFORE SERVICING.
(1)Before the power is applied.
(a)Open and close door several times to make sure
the primary interlock switch, the door sensing switch,
and the interlock monitor switch operate properly.
(Listen for the clicking sound from switches). Make
sure the interlock monitor switch is closed after the
primary interlock switch is opened, when the door is
opened. (See pages 1 and 7).
(b)Make sure the perforated screen and the dielectric
choke of the door are correctly mounted.
(2)After the power is applied.
(a)Open and close the door to see if the interlock
mechanism operates properly.
(b)Check microwave energy leakage with a leakage
detector and confirm the energy leakage is below
5mW/cm2.
(3)Do not operate the unit until it is completely
repaired, if any of the following conditions exists.
(a)Door does not close firmly against the cavity front.
(b)The hinge is broken.
(c)The choke dielectric or the door seal is damaged.
(d)The door is bent or warped, or there is any other
visible damage to the oven that may cause
microwave energy leakage.
NOTE: Always keep the seal clean
(e)Make sure there are no defective parts in the
microwave generating and transmission assembly.
(especially waveguide).
(4)Following items should be checked after the unit is
repaired.
(a)The interlock monitor switch is connected
correctly and firmly.
(b)The magnetron gasket on the magnetron is
properly positioned.
(c)Wave guide and oven cavity are intact ( no leakage
of microwave energy).
(d)The door can be properly closed and the safety
switches work properly.
(e)The oven must be stopped when the door is
opened or the time is up.
The oven must not be operated with any of the above
components removed or bypassed.
Page 4
C
150w 450w
Kg
/
AUTO
MIN
SEC
1
5
11
14
KEYS:
1. Display Window
2. Function and Accessary Indicator
3. Kitchen Timer Display
4. Auto Program Key
5. Auto-Defrost
6. Kitchen Timer Key
7. More/Less Key
8. Personal Menu Keys
9. MIcro Power
10. Delay Start
11. Quick Start
12. Clear/Stop
13. Start
14. Rotary Dial
-3-
5. OVEN CONTROL PANEL
Figure 1
Notes :
A "beep tone" sounds when a "pad" on the control panel is touched, to indicate a setting has
been entered.
When setting the controls you can keep your finger on a key until the desired setting is reached.
10
13
3
2
4
6
8
7
9
12
Page 5
SC1 : PRIMARY INTERLOCK SWITCH
SC2 : DOOR SENSING SWITCH
SC3 : INTERLOCK MONITOR SWITCH
MTCO/CFTCO : MAGNETRON/CAVITY FIRE
THERMAL CUT OUT
HT : HEATER THERMOSTAT
RL1 : MAIN RELAY
RL2 : POWER CONTROL RELAY
RL4 : GRILL HEATER RELAY
BM : BLOWER MOTOR
GM : GEAR MOTOR
L : CAVITY LAMP
ST : STEP DOWN TRANSFORMER
IR : INRUSH RESISTOR
6.CIRCUITDIAGRA
M
EM-SL20
N
MAGNETRON 2M-253H(IF)-N
2x500PF/2x1.5uH
1.14 F
HIGH VOLTAGE RECTIFIER
HIGH VOLTAGE CONDENSER
GM
BM
L
NO
COM
HIGH VOLTAGE TRANSFORMER
L1,L2 = 1mH
C1 = 0.22 F
C2,C3 = 4700PF
R = 1M
C1
R
C3
C2
L1
L2
230V ~
50Hz
SC1
MTCO/
CFTCO(122ûC)
NC
COM
SC3
RL2
21
S101
TOUCH KEY
BOARD
CONTROL
CIRCUIT
BOARD
SC2
COM
NO
RL3
RL4
5
1
3
RL1
ST
S1
H
HT(150û
o
C)
FUSE (8A T)
H.V. FUSE 0.75A
IR (25 )
OVEN CONDITION
DOOR : OPEN
-4-
- The parts marked with are supplied with
a high voltage which exceeds 250V.
- The parts marked with have special characteristics important for macrowave leakage.
When replacing any of these parts use only
manufacturer's specified parts.
Page 6
COMPONENT CHECKOUT PROCEDURE RESULTS
1) Check for resistance : Across the filament terminals of the Normal reading :
the magnetron with an ohmmeter on Rx1 scale. Less than 1 ohm.
2) Check for resistance : Across the filament terminals of Normal reading :
the magnetron and the chassis ground with an ohm-meter Infinite ohms
on highest scale.
The chart below shows the firing times of the variable power
relay for the EM-SL20 model. The table should be used as
a means to check the magnetron is operating correctly and
producing any other power setting apart from full power.
7. TEST
PROCEDURES
AND TROUBLESHOOTING
CAUTION
- DISCONNECT THE POWER SUPPLY
CORD FROM THE WALL OUTLET
WHENEVER REMOVING THE CABINET
FROM THE UNIT. PROCEED WITH THE
TESTS ONLY AFTER DISCHARGING
THE HIGH VOLTAGE CAPACITOR AND
REMOVING THE LEAD WIRES FROM
THE PRIMARY WINDING OF THE HIGH
VOLTAGE TRANSFORMER. ( See
Figure 3 )
Figure 4
A. TEST PROCEDURE
MAGNETRON
Figure 5
Figure 6
-5-
Filament Windings
Primary Windings
Secondary Winding
Power Level On Time/s % On Time
(inc.’ramp up’ time)
High (900W) 30.0 100
M-High(750W) 28.0 93
Roast (450W) 18.0 60
Simmer(300W) 13.0 43
Warm (150W) 8.0 27
Low (80W) 6.0 20
Page 7
COMPONENT CHECKOUT PROCEDURE RESULTS
1) Measure the resistance : Normal readings :
With an ohmeter on Rx1 scale.
a. Primary Winding ; Approximately 1.75 ohms.
b. Filament Winding ; Less than 1 ohm.
c. Secondary Winding ; Approximately 90.11 ohms.
2) Measure the resistance : Normal readings :
With an ohm-meter on highest scale.
a. Primary winding to ground ; Infinite ohms
b. Filament winding to ground ; Infinite ohms
Note : Remove varnish of
measured point.
1) Measure the resistance : Across two terminals with an Normal reading :
ohm-meter on highest scale Momentarily indicates several
ohms, and gradually returns
to 10 Meg-ohm.
Abnormal reading :
Indicates continuity or 10MΩ
from the beginning.
Measure the resistance : Across two terminals with an Normal reading :
ohm-meter on its highest scale. Indicates over 10MΩ in one
direction (forward direction)
and infinite ohms in the
reverse direction, using meter
which is provided with a 9-volt
battery.
NOTE
Some digital meters may
show over even in a forward
direction because low
measuring voltage of meter
does not allow the meter
current to pass through
the high voltage diode.
Abnormal reading:
Indicates continuity or infinite
ohms in both directions.
HIGH VOLTAGE
CAPACITOR
including
BLEEDER
RESISTOR
Figure 8
HIGH
VOLTAGE
DIODE
-6-
Figure 9
HIGH
VOLTAGE
TRANSFORMER
Figure 7
Page 8
COMPONENT CHECKOUT PROCEDURE RESULTS
Measure the resistance : Across two terminals with an
ohm-meter on its highest scale.
Normal reading :
Indicates continuity.
Abnormal reading :
Indicates infinite ohms.
Measure the voltage : Between test points TP-1,TP-2,
and ground (See control circuit board on page 20 ).
NOTE
Proceed with the check of the step down transformer, to
see if any one of the measured values is different from the
specified values
Figure 10
-7-
HV FUSE
Test TP-1 TP-2
point
Voltage -5V -15V
DC DC
CONTROL
CIRCUIT
BOARD
COMPLETE
Page 9
SWITCH CHECKOUT PROCEDURES DOOR OPEN DOOR CLOSE
CHECKOUT PROCEDURE FOR SWITCHES
Disconnect the lead wires from the switches and check the continuity of the switches, connecting an ohm-meter to its
terminals.
Primary Interlock
Door Sensing
Connect an ohm-meters leads to terminals "COM"
and "NO" of switch
Interlock monitor
Connect an ohm-meters leads to terminals "COM"
and "NC" of switch
CAUTION : After checking the switches, make sure that the interlock monitor switch is properly connected according to
the CIRCUIT DIAGRAM on page 4.
-8-
Page 10
B. TROUBLESHOOTING
STEP
SEQUENCE
RESULT
(1) PROBLEM
No display or mis-display in
the display window by touching
the keys.
a
Check 230V AC power
supply of connector S1
between Pin3 and Pin 5
after removing connector
S1 from control circuit
board.
Check continuity of FUSE,
Thermal Protector for cavity,
Thermal Protector for
magnetron and AC Power
Cord.
If the fuse has blown see
"D. REMOVING FUSE" on
page 13
0 230
0 Volt
0 230
230 Volt
PROBLEM
1-b
Control
Circuit Board
Check power supply voltage
on control circuit board.
(See page 7 )
Voltage
incorrect
Replace it if
necessary
0 V
0
V
Each Voltage
OK
Normal control
circuit board
Replace control
circuit board.
b
Runs
Runs
Correct seating of
connector S101 or
replace control circuit
board.
Normal control
circuit board
Runs
1
0
0
1
5
0
4
5
0
7
0
0
8
5
0
A
u
t
o
S
t
a
r
t
D
e
f
.
T
i
m
e
1
0
0
0
-9-
E
M
-S350
-9-
Page 11
STEP
SEQUENCE
RESULT
(2) PROBLEM
Cooking operation will
not start.
a
0 230
230 Volt
0 230
0 Volt
PROBLEM
3-b
No Continuity
∞ 0
0
∞
Continuity OK
Adjust or Replace
Door Sensing Switch
CHECK :
1. Power Supply to Oven
2. Primary Interlock Switch
3. Thermal protector for Cavity and Magnetron
Check continuity of connector
S102 between pins with the
door closed after removing
connector S102 from control
cct board.
Check contact
of connector S102
PROBLEM
3a
Correct Seating
Poor Contact Normal Contact
Contact OK
Normal Door
Sensing Switch
Touch START key and measure
voltage between the two wire
leads from primary windings of
H.V transformer after removing
the wire leads from terminals of
H.V transformer
Replace Control
Circuit Board
Normal Control
Cct. board
(3) PROBLEM
Oven does not heat up
a
-10-
Runs
Runs
Runs
-10-
Page 12
STEP
SEQUENCE
RESULT
b
Resistance
OK
Replace control
circuit board.
(4) PROBLEM
Low microwave power
output.
a
Normal control
circuit board
Replace Blower
motor
∞ 0
Resistance
incorrect
∞
274
Normal
Resistance
Replace thermal protector
for magnetron or thermal
protector for cavity.
∞
0
∞
0
Defective H.V capacitor,
H.V diode or H.V. fuse.
Replace HV
capacitor, H.V
diode or H.V.
fuse.
Replace HV
Magnetron.
Runs
Runs
Runs
Runs
Runs
Runs
A
u
t
o
S
t
a
r
t
D
e
f
.
T
i
m
e
A
u
t
o
S
t
a
r
t
D
e
f
.
T
i
m
e
A
u
t
o
S
t
a
r
t
D
e
f
.
T
i
m
e
A
u
t
o
S
t
a
r
t
D
e
f
.
T
i
m
e
A
u
t
o
S
t
a
r
t
D
e
f
.
T
i
m
e
A
u
t
o
S
t
a
r
t
D
e
f
.
T
i
m
e
-11-
Normal Blower
Motor
Measure resistance
of blower motor
(Approx 274 ohms)
No
Operation
Normal thermal protector for
magnetron or thermal
protector for cavity.
Normal
Operation
Temporarily
short across
terminals of
thermal protector
for magnetron
or thermal
protector for
cavity by using
jumper lead.
No
Operation
Normal
Operation
PROBLEM
3-b
Check operation
of blower motor
when START key
is touched.
Check resistance of
each winding after
removing lead wires.
(See page 6)
Normal HV Transformer
Check H.V capacitor , H.V.
diode or H.V fuse with an
ohm-meter after removing
the lead wires.( See page 7 )
∞
0
∞
0
Resistance
Correct
Normal H.V capacitor,
H.V diode or H.V. fuse.
Replace HV
Transformer
Normal
Magnetron
Normal H.V
capacitor ,
diode or fuse.
U
p
U
p
U
p
U
p
U
p
U
p
6
5
-11-
Page 13
STEP
SEQUENCE
RESULT
(5) PROBLEM
The magnetron operates on
high level when a lower cook
power is selected.
a
0 230
0 Volt
0 230
230 Volt
No problem
Measure water
temperature rise
exactly.
Replace control
circuit board.
Normal control
circuit board
Replace control
circuit board.
(6) PROBLEM
Unit does not heat up even
if display counts down when
key is touched for
"Grill Cooking".
a
Normal control
circuit board
Replace Heater
∞
52
Normal
Resistance.
0
∞
Resistance
Incorrect.
EM-G451
Auto
Start
Def. Dual Grill Time
DIRECT ACCESS
EM-G451
Time of day
Grill
Dual
150w
Dual
450w
Chilled
Meal
Liquid
Jacket
Potato
Pizza
Pork
Chops
Chicken
Pieces
Auto
Defrost
Down
Up
Timer/Weight
100 150 450 700
850 1000
Power
Delay
Start
Start
C
Clear/Stop
1
0
0
1
5
0
4
5
0
7
0
0
8
5
0
A
u
t
o
S
t
a
r
t
D
e
f
.
T
i
m
e
1
0
0
0
Runs
Runs
Check resistance of
heater.
Approximately 41.7Ω
measured over
both tubes.
Set power level
at low.
Touch START key and measure
voltage between leads for
primary winding of H.V transformer
after removing the wire leads from
terminals of H.V transformer.
-12-
Runs
Normal Heater
E
M
-
S
3
5
0
Check resistance of
heater.
Aproximately 48.7Ω
measured over both
terminals.
C
150w 450w
Kg
/
AUTO
MIN
SEC
Page 14
8.DISASSEMBLY INSTRUCTIONS
- OVEN MUST BE DISCONNECTED FROM ELECTRICAL OUTLET WHEN MAKING REPLACEMENTS,
REPAIRS, ADJUSTMENTS, AND CONTINUITY
CHECKS BEFORE PROCEEDING WITH ANY REPAIR
WORK AFTER DISCONNECTING. WAIT AT LEAST 1
MINUTE, UNTIL THE CAPACITOR IN THE HIGH VOLTAGE AREA HAS FULLY DISCHARGED.
- WHEN REPLACING ANY DOOR MICRO SWITCH,
REPLACE WITH THE SAME TYPE SWITCH SPECIFIED ON THE PARTS LIST.
A. REMOVING PRIMARY INTERLOCK SWITCH,
DOOR SENSING SWITCH AND INTERLOCK
MONITOR SWITCH
(See Figure 1 on page 1 and Figure 12 on this page)
(1) Remove 2 screws securing the lever stopper.
(2) Disconnect all lead wires from the primary interlock
switch, door sensing switch and the interlock monitor
switch
(3) Ease away the retaining clips holding the Primary
interlock switch onto the lever stopper and remove.
(4) Remove the door sensing switch by reference to the
step (3).
(5) Remove the interlock monitor switch by reference to
step (3).
(6) Make the necessary adjustment, and make microwave
energy leakage check according to “1. ADJUSTMENT
PROCEDURES” on page 1. After the switch is
replaced with a new one, check proper operation of it
according to “CHECKOUT PROCEDURE FOR
SWITCHES” on page 8.
Interlock Switch Replacement - when replacing faulty
switches, be sure switch retaining clips are not bent,
broken or otherwise deficient in their ability to secure
the switches in place.
B. REMOVING THE ANTENNA
(See exploded view on page 15 )
(1). Remove the screw securing the cavity cover to the
cavity.
(2). Remove the antenna complete by slightly bending it
so the retension clips holding it slide out of the cavity
wall.
C. REMOVING MAGNETRON
(See exploded view on page 16 )
(1) Remove the antenna complete according to
B. REMOVING THE ANTENNA.
(2) Disconnect the 2 lead wires from the magnetron.
(3) Remove 1 screw securing the duct to the
magnetron, and take out the duct.
(7) Remove 4 screws securing the magnetron to
the waveguide.
Take out the magnetron VERY CAREFULLY.
NOTES
- When removing the magnetron, make sure that its dome
does not hit any adjacent parts, or it may be damaged.
- After replacing the magnetron, be sure to check the
microwave energy leakage with a leakage detector and
confirm the leakage is below 5 mW/cm2 .
D. REMOVING FUSE
(A) Remove the 8A fuse with a screwdriver.
- When replacing the 8A fuse, be sure to use an exact
repair part.
- If the 8A fuse blows immediately, check the primary
interlock switch and the interlock monitor switch (termi
nals “C” and “NC”) according to “CHECKOUT
PROCEDURE FOR SWITCHES” on page 8, and make
sure to check the microwave energy leakage according
to “1. ADJUSTMENT PROCEDURE” on page 1, when
the primary interlock switch or the interlock monitor
switch is replaced.
- If the primary interlock switch is defective, replace not
only the primary interlock switch but also the interlock
monitor switch.
Then install a new 8A fuse.
- If the primary interlock switch and the interlock monitor
switch (terminals “C” and “NC”) operate properly,
determine which of the following is defective: blower
motor, turntable motor, high voltage transformer, high
voltage capacitor, high voltage diode or magnetron.
- If the high voltage diode is defective , replace not
only the high voltage diode but also the HV fuse.
E. REMOVING
DOOR
(1) Remove the 2 screws securing the upper hinge.
(2) Tilt the top of the door toward you.
(3) Lift up the door to remove it.
When replacing the door body or door assembly
the new door has to be set properly ensuring the correct
door gap between door body and cavity front.
To set the new door;
1. Mount door loosely on cavity.
2. Before tigthening the top and bottom hinge screws
place feeler gauges (the thickness varies for different
models- see table below) between the door assembly and
the cavity front plate between the top and bottom hinges.
NB. Be careful not to scratch the door cover with the feeler gauges.
3. The door should then be aligned with the control base
and held firmly in place leaving a gap within 1-2mm.
between the door cover and control base.
LEVER STOPPER
MICROSWITCH
RETAINING
CLIPS
-13-
Figure 12
Page 15
4. The hinge screws should then be tightened to hold the
door in place, and the feeler gauges removed.
5. The door gap should then be checked again using feeler
gauges.
Below is a table giving the door setting for the:-
EM-SL20N
After setting the door gap, the door is closed with the door
latch fully engaged and the screws securing the switch
base are loosened. The switch base is then eased to the
right to pull the door face hard onto the front of the
microwave. The screws are then secured tight. To check if
the operation has been carried out correctly push the door
top and bottom. Any movement should be minimal, and
the door should feel tight to the front face of the
microwave.Confirm that the operation has been successfully carried out by depressing the door release lever until
the microswitches are heard to operate. This occurs just
before the door opens.
NOTES
- After replacing the door, be sure to check that the
primary interlock switch, door sensing switch and the
interlock monitor switch operate normally. (See
page 1).
- After replacing the door check for microwave energy
leakage with a leakage detector.
Microwave energy leakage must be below the limit of
5mW/cm2.
F. DISASSEMBLYING
DOOR
( See exploded view on page 18 )
(1) Insert a thin flat blade screwdriver between the
choke dielectric and the door mainframe and lift
up the choke dielectric to release the hooks one
by one.
(2) To remove door cover, remove the 2 screws
securing the door cover to the door main frame
(3) Insert a thin flat blade screwdriver between the
door cover and door mainframe and release the
hooks one by one.
(4) To detach the glass door panel, insert a thin flat
blade screwdriver between the door panel and
door cover and release the clips one by one.
NOTES
- The choke dielectric, the glass door panel and the
door cover may be damaged when they are removed.
When re-installing them, replace them with new ones
if they are damaged.
- After installing the door in place, check for microwave
energy leakage with a leakage detector.
Microwave energy leakage must be below the limit of
5mW/cm2.
G. CHANGiNG POWER SUPPLY CORD
(See exploded view on page 16 )
(1) Removing the earthing screw.
(2) Remove the power supply cord from the terminal
of PCB complete.
DOOR GAP
Lower Limit Upper Limit
0.2mm. 0.8mm.
(3) Remove power cord from cavity assembly by
lifting cord bush, moving it to the left and pulling it
away from cavity rear plate.
(4) Install the new power supply cord with the
reverse procedure of above (1) to (3).
WARNING
For changing the power supply cord, never use parts
other than the following :
Part Name : Power Supply Cord Assembly
Part No : 617 213 2990 (Continental)
H. REMOVING TURNTABLE
MOTOR COVER
(Refer to Figures 13 and 14 below )
(1) Turn the unit and cut the 6 joints of the bottom
plate and the motor cover using diagonal pliers
(nipper). (See Figure 13 )
(2) Seperate the motor cover and the bottom plate.
NOTES
- Bend the cut joints inside slightly for safety and be
careful of the sharp edges.
RE-INSTALL :
(1) Rotate the motor cover through 180˚.
(2) Insert the edge of the motor cover into the tab on
the bottom plate.
(3) Secure the motor cover by screwing it to the
bottom plate (See Figure 14 )
Use screw 411 156 5502 (not supplied with oven)
Clip metal here
and at other 5
locations.
Retaining Lugs
Metal Tabs
Insert screw here to
secure.
Tabs fit into
retaining lugs.
Figure14
Figure13
-14-
Page 16
-15-
1
2
2
3
2
4
5
10
12
11
9
8
7
6
13
15
16
2
8. EXPLODED VIEW AND PARTS LIST
CAVITY PARTS
Key Part No. Description Q'ty
No.
13 617 221 0025 Heater Complete 1
14 617 202 4554 Thermostat, 150˚C 1
15 617 167 0431 Duct 1
16 617 169 6875 Frame Rear Plate 1
17 617 166 2153 Cook Net (H) 1
18 617 170 5058 Cook Net (L) 1
19 411 010 5600 SCR EVR PAN 3x6 1
Key Part No. Description Q'ty
No.
1 617 220 4376 Cabinet 1
2 411 156 5601 SCR TPG PAN+F+S 4x10 7
3 MO-A0730 Cavity 1
4 MO-S1121 Gear Motor 1
5 411 001 6005 SCR S-TPG PAN 4x8 2
6 MO-R0132 Special Washer 1
7 617 184 7659 Turntable Shaft 1
8 617 215 9560 Roller Base Ass'y 1
9 617 167 1421 Glass Tray 1
10 MO-A0737 Antenna Complete 1
11 617 169 8930 Cavity Cover 1
12 412 037 5901 SCR TPG TRS 4x6K 1
EM-SL20N
2
18
17
14
19
Page 17
-16-
1
18
24
5
3
3
3
2
6a
7
8
9
10
11
12
13
14
15
16
17
20
21
19
3
22
3
25
26
27
4
28
3
SWITCHES AND MICROWAVE PARTS
Key Part No. Description Q'ty
No.
1 411 010 5600 SCR EVR PAN 3x6 1
2 411 156 5601 SCR TPG PAN+F+S 4x10 1
3 411 156 5502 SCR S-TPG PAN+F+S 4x10 6
4 411 171 9004 SCR TPG TRS+FLG 3x8 1
5 617 213 2990 Power Supply Cord 1
6a 617 179 0746 PCB Complete (N-F) 1
6b 423
027 8802 Fuse 1
7 617 167 0417 Space Partition 1
8 617 162 2041 Capacitor Band 1
9 MO-S0856 Capacitor 1.14uF 1
10 MO-S0947AS Diode Ass'y 1
11 617 234 1934 Lead Wire Ass'y 1
12 617 182 2915 HV Fuse 1
13 617 229
3769 Blower Motor 1
14 MO-S1118 Magnetron 1
15 617 112 1025 Fan 1
16 MO-M1211 Duct 1
EM-SL20N
Key Part No. Description Q'ty
No.
17 617 195 3428 Latch Lever 1
18 617 189 0839 Lever Stopper 1
19 617 244 0651 Door Sensing Switch 1
20 617 244 0644 Interlock Monitor Switch 1
21 617 244 0651 Primary Interlock Switch 1
22 MO-S0587 Lamp Ass'y 1
24 617 202 4561 Thermostat V122˚C 1
25 617 220 1757 Stay Plate 1
26 617 218 9673 Special Screw 4
27 411 004 5609 NUT HEX M4 1
28 402 071 0703 Ceramic Resistor 1
Page 18
MICROWAVE PARTS
Key Part No. Description Q'ty
No.
1 617 209 4557 Transformer 1
2 617 225 1721 Special Screw 2
3 617 225 6153 Bottom Plate Assembly 1
4 ------------------ Gear Motor Cover 1
5 617 144 5435 Foot Cushion Assembly 4
6 617 166 7493 Bottom Hinge 1
7 411 156 5602 SCR S-TPG PAN+F+S 4x10 1
8 617 102 7495 Special Screw 2
-17-
1
3
4
5
8
6
7
EM-SL20N
2
2
Page 19
DOOR PARTS
Key Part No. Description Q'ty
No.
1 MO-A0748 Door Cover Assembly 1
2 MO-A0768 Door Main Frame(Supplied 1
with inner Door Panel)
* 617 144 2472 Glass Inner Door Panel 1
3 617 167 0189 Hinge 1
4 617 167 1292 Choke Dielectric 1
5 617 195 3411 Door Latch 1
6 617 101 1494 Spring 1
* MO-A0756 Door Assembly 1
-18-
3
2
4
6
5
EM-SL20N
Inner Door Panel always
supplied with Door Main Frame
but can be ordered seperately
quoting number below.
NB. Please refer to the detailed instructions for door
setting on page 14 of the service manual before
changing, adjusting or repairing these parts.
1
Page 20
Key Part No. Description Q'ty
No.
1 MO-A0749 Control Base Assembly 1
2 617 236 6463 Knob Body 1
3 617 219 5520 PCB Complete 1
4 617 224 0275 PCB Complete 1
6 617 197 4836 PCB Complete 1
7 617 181 7980 Latch Lever 1
8 MO-A0747 Handle Assembly 1
9 617 188 3329 Spring 1
10 617 224 1067 Knob Assembly 1
11 411 064 6608 SCR TPG BIN 3x8 11
12 617 231 3047 Special Nut (Metal) 1
* MO-P5257 Operating Instructions (EES) 1
* MO-P5276 Carton Box 1
-19-
9
1
2
8
* These items not illustrated
CONTROL PANEL PARTS
EM-SL20N
3
11
4
7
6
10
12
11
13
Page 21
10.CONTROL CIRCUIT
BOARD
EM-SL20N
Model Spares No. RL3 M.Processor
EM-SL20N 617 224 0275 Yes IC11 LM8842
-24-
Page 22
11. OVERALL CIRCUIT DIAGRAM
EM-SL20N
-21-
IC 11 LM8842
P65/AN5
P64/AN4
P61/AN1
C103
0.01u
50V
R120
10K
D111
513
V5T1
RL1
12
Q107
DTA143X
-15V
4.7K
10K
DOOR
SENSING
SWITCH
S1 3/5P
53062-0310
PT1 PD5TK-S150
-5V
93
40
R115 3.3K
R116
1K
BZ1
2KHZ
R119
10K
C106
0.01u
50V
19
XIN
XOUT
P50
P47
P54
P56/TOUT
AVSS
VSS
P63/AN3
P62/AN2
D11
1N4002 X4
C12
47u
/10V
-5V
-15V
D15
1N4002
C13
470u
/35V
ZD11
RD5.6ESB3
R11
4.7K
C15
1000P
/50V
C16
0.01u
/50V
D12
C14
0.01u
/50V
D13
D14
Q11
A564A
R12 2.7K
C11
470u
/35V
R1
3
R1
4
ZD13
ZD12
Q12
B123B
RD7.5ESB3 X2
C107
0.1u
/25V
OPEN
R121
10K
R122
100K
R123
100K
R124
100K
-5V
98992
VL3
VL2
VL1
R117
10K
-5V
Q108 A564A
R118
10K
OPEN
OPEN
OPEN
151617
OPEN
232526
OPEN
D103
1N4002
OPEN
18
OPEN
OPEN
OPEN
-5V
R105 4.7K
569
P57
11
10
P60/AN0
P43
P41
P40
P53
P52
P51
P42/INTO
P55/CNTR1
VCC
VREF
139192
24
2
1
D102
S102
5267-03A
R104
10K
C102
0.01u
/50V
R140 4.7K
1
2
3
S301 EH3P
R304
10K
C302
1000P
/50V
R303
10K
R301 10K
R302 10K
-5V
C301
1000P
/50V
97-94
90-68
67-58
55
54
53
525150
49
484746
1-4
5-27
39-28
COM1-4
LCD1 H4062
COM0-3
SEG0-22
SEG23-34
P11/SEG35
P12/SEG36
P13/SEG37
P14/SEG38
P15/SEG39
P16
P17
P20
P21
P22
Q101
DTA123X
2.2K
10K
-5V
39
38
RS1
4MHZ
R103
560K
D101
C1011µ/50V
R102
10K
ZD101
RD3.9
ESB2
R101
1K
RST
35
RL2
OPEN
7
8
TIMER SW
SW BOARD
(12700)
OPEN
OPEN
OPEN
OPEN
OPEN
LED1 LED2 LED3 LED4 LED5
R152
10K
R151
390Ω
R153
1.2K
Q151
A564A
27
P77
-15V
3
4
34
-5V
P67/AN7
P66/AN6
P70
R52 12K
R54 12K
R56 12K
37
36
P80
P81
OPEN
OPEN
-5V
42312
OPEN
OPEN
C1
C2
1
100
OPEN
OPEN
33
32
313029
28
OPEN
OPEN
OPEN
OPEN
OPEN
OPEN
P71
P72
P73
P74
P74
P75
P76
P23
P24
P24
P26
P27
45
44
43
42
41
R129 10K
R12810K
R12710K
R126 10K
R125 10K
R101
100K x5
R130
R131 R132
4.7K X5
5
3
1
4
2
12
14
16
13
15
7
9
11
13
15
6
8
10
12
14
16
10
8
6
4
2
11
9
7
5
3
1
SW2
SW9-2
SW10
SW11
SW6
SW5
SW4
SW3
SW13
SW12
SW8
SW9-1
SW14
DELAY
START
A.DEF
MICRO
POWER
QUICK
START
GRILL
KITCHEN
TIMER
MORE/
LESS
CLEAR/
STOP
START
AUTO
GRILL
450W
GRILL
150W
S101
52045-1645
S103
52044-1645
SW BOARD
(31900)
MAGNETRON
2x500PF/2x1.5uH
HIGH VOLTAGE RECTIFIER
HIGH VOLTAGE CONDENSER
GM
BM
CL
HIGH VOLTAGE TRANSFORMER
MQ/OVEN
THERMO
PRIMARY
SWITCH
230V
50Hz
C1
R
C3
C2
L1,L2 = 1mH
C1 = 0.22µF
C2,C3 = 4700PF
R = 1MΩ
L1
L2
MONITOR SWITCH
HEATER
THERMO
GRILL
HEATER
FUSE
8A(T)
RL4
CAPACITOR
2.2K
10K
Q102
DTA123Y
D107
D104
R106 R107
18Ω x 2
MQ
RL2
RL3
INRUSH
RESISTOR
Q105
C1741
R114
150Ω
4.7K
10K
Q106
DTA143X
R112
4.7K
R113
47K
14
CL
RL1
D110
OPEN
OPEN
2.2K
10K
Q104
DTA123Y
D109
D106
R110 R111
18Ω x 2
GRILL
HEATER
2.2K
10K
Q103
DTA123Y
D108
D105
R108 R109
18Ω x 2
INRUSH
22
21
20
P46
P45
P44
Page 23
2002-09
Please Note
All the information that appears in this service manual was
correct at the time of production. SANYO Electric Company
reserves the right to make changes to parts or processes in
order to maintain their policy of continuing improvement.
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