Sanyo EM-sl30 Schematic

SERVICE MANUAL	STAINLESS STEEL
	MICROWAVE OVEN WITH
	CONVECTION AND GRILL

MIN	SEC
AUTO
1.
2.
3.
	C
	/	Kg

FILE No.

EM-SL30NEUKUK

MIN SEC

AUTO

1.

2.

3.

C

/ Kg

Product Code No.

EM-SL30NEUK 1-437-574-26

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.

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 other damage), (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-2400004

	TABLE OF CONTENTS
Adjustment Procedures........................................	1	Circuit Diagram....................................................	4
Specifications.......................................................	2	Test Procedures and Troubleshooting.................	5-15
Power Output Measurement................................	2	Disassembly Instructions.....................................	16-17
Precautions and Repair Service Tips...................	2	Exploded View and Parts list................................	18-23
Oven Control Panel..............................................	3	Control Circuit Board............................................	24
		Overall Circuit Diagrams......................................	25

CAUTION

MICROWAVE ENERGY

PERSONNEL SHOULD NOT BE EXPOSED TO

THE MICROWAVE ENERGY WHICH MAY RADI-

ATE FROM THE MAGNETRON OR OTHER

MICROWAVE GENERATING DEVICE IF IT IS

IMPROPERLY USED OR CONNECTED. ALL

INPUT AND OUTPUT MICROWAVE CONNEC-

TIONS, WAVE GUIDES, FLANGES, AND GAS-

KETS MUST BE SECURE. NEVER OPERATE

THE DEVICE WITHOUT A MICROWAVE ENER-

GY ABSORBING LOAD ATTACHED. NEVER

LOOK INTO AN OPEN WAVE GUIDE OR

ANTENNA WHILE THE DEVICE IS ENERGISED.

			Lever Stopper
	1. ADJUSTMENT PROCEDURES
	TO AVOID POSSIBLE EXPOSURE TO MICRO-WAVE
				Screw
	ENERGY LEAKAGE, THE FOLLOWING ADJUST-
				Positions
	MENT OF THE INTERLOCK SWITCHES SHOULD
	BE MADE ONLY BY AUTHORISED SERVICE
						Door Latch
	PERSONNEL
	PRIMARY INTERLOCK SWITCH, DOOR SENSING
					Door Sensing
	SWITCH AND INTERLOCK MONITOR SWITCH
					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						Lever
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									Interlock Monitor
on the primary interlock switch.									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 9.
(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 9.
(6) Make sure the microwave energy leakage is below
the limit of the regulation (5mW/cm2) when				Primary Interlock
	Latch Lever
measured with a detector. ( All service				Switch
adjustments must be made for minimum energy
leakage readings.)
										Figure 1

-1-

2. SPECIFICATIONS - EM-SL30N

Rated Power Consumption........		Micro. 1450+15%W
		Conv. 1200+5/-10%W
		Grill 1100+5/-10%W
		Dual 2550+15%W
		(After 15mins.)
Microwave Output......................		900W
Frequency..................................		2,450MHz ± 50MHz
Power Supply.............................		230V,50Hz
Rated Current.............................		6.45±10% Amps Micro
		5.3±10% Amps Conv.
		4.95±10% Amps Grill
		11.5±10% Amps Dual
		(After 15mins.)
Safety Devices...........................		Thermal Protector for
		Magnetron and Cavity,
		Open at 122˚C.
		Thermal Protector for
		Heater, Open at 150˚C.
		Thermal Protector for
		Convection, Open at
		122˚C
		Fuse (Cartridge Type
		8A)
		Primary Interlock Switch
		Door Sensing Switch
		Interlock Monitor Switch
Timer..........................................		Electronic Digital
		Micro,90min
		Convection, 90 mins
		Grill, 90 mins
Oven Temperature Control.........		Convection,
		40˚C-250˚C
		Dual,
		100˚C-250˚C
Overall Dimensions.........	490(W)x445(D)x322(H)mm
Oven Cavity Size.............	304(W)x305(D)x248(H)mm
Turntable Diameter.....................		262mm
Net Weight..................................		Approx. 20Kg.

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.

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 9).

(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).

(f)Make sure there are no defective parts in the inter lock mechanism.

(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.

-2-

5. OVEN CONTROL PANEL
	2			1
		MIN	SEC
				3
	4	AUTO
				5
	6			7
				8
	9	1.		10
		2.
		3.
				C
	11			12
				13
				/ Kg
				14
				Figure 1
KEYS:
1.	Display Window		8.	Personal Menu Keys
2.	Function and Accessary Indicator		9.	Slow Cook
3.	Kitchen Timer Display		10. Dual Cook
4.	Auto Program Key		11. Quick Start
5.	Auto-Defrost		12. Clear/Stop
6.	Kitchen Timer Key		13. Start
7.	More/Less Key		14. Rotary Dial

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.

-3-

6.CIRCUIT DIAGRAM EM-SL30N

OVEN CONDITION

DOOR : OPEN

TOUCH KEY

BOARD

S101

RL3

CONTROL

CIRCUIT

BOARD

	RL4
		S1
	ST	1
	RL1	3
		5
	PHC	7
	VST
	RL5	9
RL7	RL2
	S102	1
		2
S201
2	1

OT

		230V ~
		50Hz
	L1,L2 = 1mH		FUSE (8A T)
		C1
	C1 = 0.22 F
	C2,C3 = 4700PF	R
	R = 1M	L2	L1
		C3	C2
			MTCO/
			CFTCO
			CL
H	HT		BM

SH SHTCO

COM SC3 NC

COM

SC1

CM

NO

IR

TM

HIGH VOLTAGE TRANSFORMER

SC2 COM

NO

HV FUSE

MAGNETRON 2M-253H(IF)-N

1.14uF

HIGH VOLTAGE CONDENSER HIGH VOLTAGE RECTIFIER

2x500PF/2x1.5uH

SC1	: PRIMARY INTERLOCK SWITCH
SC2	: DOOR SENSING SWITCH
SC3	: INTERLOCK MONITOR SWITCH
HT	: GRILL HEATER THERMOSTAT
MTCO/ : MAGNETRON/CAVITY FIRE THERMAL
CFTCO CUT OUT
SHTCO: CONVEC. HEATER THERMAL CUT OUT
RL1	: MAIN RELAY
RL2	: POWER CONTROL RELAY
RL3	: GRILL HEATER RELAY
RL4	: CONVEC. HEATER RELAY
RL5	: FAN MOTOR RELAY
IR	: INRUSH RESISTOR

BM :		BLOWER MOTOR
CM	:	CONVEC. FAN MOTOR
TM	:	TURNTABLE MOTOR
DM	:	DUMPER MOTOR
CL	:	OVEN LAMP
H	:	GRILL HEATER
SH	:	CONVEC. HEATER
OT	:	OVEN THERMISTOR	Figure 3

- The parts marked with	are supplied with
a high voltage which exceeds 250V.
- The parts marked with	have special char-

acteristics important for macrowave leakage. When replacing any of these parts use only manufacturer's specified parts.

-4-

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 )

A. TEST PROCEDURE

Filament Windings

Secondary Winding

Primary Windings

Figure 4

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.

	Figure 5
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.

MAGNETRON

Figure 6

The chart below shows the firing times of the variable power relay for the EM-SL30 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.

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

-5-

COMPONENT	CHECKOUT PROCEDURE	RESULTS
	1) Measure the resistance :	Normal readings :
	With an ohmeter on Rx1 scale.
	a. Primary Winding ;	Approximately 1.7 ohms.
	b. Filament Winding ;	Less than 1 ohm.
	c. Secondary Winding ;	Approximately 92 ohms.
	2) Measure the resistance :	Normal readings :
	With an ohm-meter on highest scale.
	a. Primary winding to ground ;	Infinite ohms
HIGH	b. Filament winding to ground ;	Infinite ohms
VOLTAGE
TRANSFORMER
		Note : Remove varnish of
		measured point.

Figure 7

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.

HIGH VOLTAGE

CAPACITOR

Abnormal reading :

including

Indicates continuity or 10MΩ

BLEEDER

from the beginning.

RESISTOR

Figure

8

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.

HIGH

NOTE

VOLTAGE

Some digital meters may

DIODE

show over even in a forward

direction because low

measuring voltage of meter

does not allow the meter

current to pass through

Figure 9

the high voltage diode.

Abnormal reading:

Indicates continuity or infinite

ohms in both directions.

-6-

COMPONENT

CHECKOUT PROCEDURE

RESULT

Measure the resistance: Between the Pin 1 and

Normal Reading:

THERMISTOR

Pin 3 of connector S103 after disconnecting

Approximately

it from the control circuit board with an

1800K ohms @ 20˚C

ohm-meter on the highest scale.

1400K ohms @ 25˚C

Normal Reading:

CONVECTION

Measure the resistance: After removing the lead

HEATER

wires from the convection heater with an

Approximately 46 ohms

(BACK HEATER)

ohm-meter on R x 1 scale.

Normal Reading:

Measure the resistance: After removing the lead

GRILL HEATER

wires from the grill heater with an

(UPPER HEATER)

Approximately 48.7 ohms

ohm-meter on R x 1 scale.

Normal Reading:

Measure the resistance: After removing the lead

BLOWER

wires from the blower motor with an

MOTOR

Approximately 300 ohms

ohm-meter on R x 100 scale.

Normal Reading:

Measure the resistance: After removing the lead wires

CONVECTION

from the convection fan motor with an ohm-meter on

FAN MOTOR

Approximately 180 ohms

R x 100 scale.

Normal Reading:

Measure the resistance: After removing the lead

TURNTABLE

wires from the turntable motor with an ohm-meter

MOTOR

Approximately 16K ohms

on highest scale.

-7-

COMPONENT

CHECKOUT PROCEDURE

RESULTS

Measure the resistance : Across two terminals with an ohm-meter on its highest scale.

Normal reading :

Indicates continuity.

HV FUSE	Abnormal reading :
	Indicates infinite ohms.

			Figure 10
		Measure the voltage : Between test points TP-1,TP-2
		and ground ( See control circuit board on page 24 ).
	CONTROL
					Test	TP-1	TP-2
	CIRCUIT	NOTE
					point
	BOARD	Proceed with the check of the step down transformer, to
					Voltage	-5V	-15V
	COMPLETE	see if any one of the measured values is different from the
						DC	DC
		specified values

-8-