Sanyo EM-D953 Service Manual

			FILE No.
SERVICE MANUAL	MICROWAVE OVEN WITH	EM-D953(UK WHITE)
	CONVECTION AND GRILL	EM-D953(UK GREEN)
		EM-D953(UK BROWN)

Auto Def. Grill			Convec.	Time	Start
				Kg
				LB
				OZ
80 150		300	450	750 900
D I R E C T			AC C E S S
Baked		Chicken		Frozen
Potato		Pieces
					Pizza
Roast	Casserole				Cake/
Joint
				Pudding
Baked		Chops/
Fish				Snacks
		Steaks
Slow Cook	Auto Defrost
Low / High				More / Less
Micro
Power Convec.					Grill
			Temp.
1.	+ Micro
2. Convec.
3. Convec.	+ Grill			Dual Cook
Micro + Grill
Up				Clear/Stop
TIMER / WEIGHT				C
Down				Start
					EM-D953

Auto Def. Grill		Convec. Time Start
				Kg
				LB
				OZ
80 150	300	450	750 900
D I R E C T AC C E S S
Baked	Chicken			Frozen
	Pieces			Pizza
Potato
Roast	Casserole			Cake/
				Pudding
Joint
Baked	Chops/			Snacks
Fish
	Steaks
Slow Cook	Auto Defrost			More / Less
Low / High
Micro Power Convec.Temp.				Grill
1. Convec. + Micro			Dual Cook
2. Convec. + Grill
3. Micro + Grill
			Clear/Stop
Up				C

TIMER / WEIGHT

Down	Start
	EM-D953

Product Code No.

EM-D953(UK White)	43736813
EM-D953(UKGreen)	43736815
EM-D953(UK Brown)	43736814

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.

ENG 030

REFERENCE No. SM-850092

	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.

1. ADJUSTMENT PROCEDURES
	Lever Stopper
TO AVOID POSSIBLE EXPOSURE TO MICRO-WAVE
ENERGY LEAKAGE, THE FOLLOWING ADJUST-			Door Latch
MENT OF THE INTERLOCK SWITCHES SHOULD
BE MADE ONLY BY AUTHORISED SERVICE
				Lever
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

the door sensing switch.

2-2. Between the lever and the switch body
				Interlock Monitor
on the interlock monitor switch.
				Switch
2-3. Between the latch lever and the switch body
on the primary interlock switch.
			Door Latch
when the door latch is securely locked.
						Latch Lever
(3) Tighten the lever stopper screws securely.
(4) Make sure the interlock monitor is closed after
					Primary Interlock
the primary interlock switch opens when the door is
					Switch
	Screw
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
measured with a detector. ( All service
adjustments must be made for minimum energy
leakage readings.)
					Figure 1

-1-

2. SPECIFICATIONS - EM-D953

Rated Power Consumption........		Microwave 1625W
		Convection 1200W
		Grill 1300W
		Dual 2860W
Microwave Output......................		900W
Frequency..................................		2,450MHz ± 50MHz
Power Supply.............................		230V,50Hz
Rated Current.............................		6.4±10% Amps Micro
		(After 15mins.)
		5.3±10% Amps Conv.
		(After 15mins.)
		5.5±10% Amps Grill
		(After 15mins.)
		11.4±10% Amps Dual
		(After 15mins.)
Safety Devices...........................		Thermal Protector for
		Magnetron, Open
		at 135˚C.
		Thermal Protector for
		Cavity, Open at 150˚C.
		Thermal Protector for
		Heater, Open at 122˚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 x 3 Stages
		Convection, 90 mins
		Grill, 90 mins
Oven Temperature Control.........		Convection,
		40˚C-250˚C
		Dual,
		150˚C-250˚C
Overall Dimensions.........	570(W)x482(D)x355(H)mm
Oven Cavity Size.............	348(W)x344(D)x251(H)mm
Turntable Diameter.....................		325mm
Net Weight..................................		Approx. 24Kg.

3. POWER OUTPUT MEASUREMENT

(1)Prepare 1000±5g tap water.

(2)Adjust water temperature to 10oC±2oC.

(3)Pour water into a container made of borosilicate glass, 190mm outer diameter cylinder, maximum 3mm thickness.

(4)Place the container in the centre of the oven cavity.

(5)Set the heating time for 47 seconds at full power and start the oven.

(6)Take the container out immediately when heating time is up.

(7)Stir water for making even water temperature in the container.

(8)Measure water temperature.

Water temperature rise should be between 8˚C to 12˚C for correct power output.

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

6

7

10

Notes :

A "beep tone" sounds when a "pad" on the control panel is touched, to indicate a

setting has been 14 entered.

When setting the controls you can keep your finger on a key until the desired setting is reached.

1.DISPLAY WINDOW.

2.INDICATORS:

Auto / Def. / Grill/ Convec -

Cooking mode indicators.

Time / Start / Kg, LB, OZ -

A flashing indicator that prompts you to enter the desired cooking time,start the oven, or enter food weight.

80, 150, 300, 450, 750, 900

Power level indicators.

Auto Def. Grill Convec. Time Start

					Kg	1
					LB
					OZ
80 150		300	450	750 900
D I R E C T AC C E S S						3
Baked		Chicken			Frozen
		Pieces			Pizza
Potato
Roast	Casserole				Cake/	4
					Pudding
Joint
Baked		Chops/			Snacks
Fish
		Steaks
Slow Cook	Auto Defrost				More / Less	5
Low / High
Micro Power Convec.Temp.					Grill	8
						9
1. Convec. + Micro				Dual Cook		11
2. Convec. + Grill
3. Micro + Grill
Up				Clear/Stop		12
					C
TIMER / WEIGHT					Start
Down						13
					EM-D953

Figure 2

KEYS:

3.Clock Set.

4.Direct Access menu keypad.

5.Time adjust for Auto Defrost and Direct Access

6.Auto Defrost

7.Slow Cook.

8.Grill only.

9.Convection Temp. only.

10.Microwave Power.

11.Dual Cook:

1.Convection+Micro

2.Convection+Grill

3.Micro+Grill

12.Clear / Stop.

13.Start.

14.Time and Weight set.

-3-

6.CIRCUIT DIAGRAM				230V 50Hz
EM-D953 UK Version				N		L
OVEN CONDITION									MT
DOOR : OPEN			L1,L2 = 1.0mH			BR	HAT	BL
			C1 = 0.22µF		C1
			C2,C3 = 4700PF
			R = 1MΩ		R				BR
						8.0A(T)
				L2	L1	BK	BK		Y
TOUCH KEY
BOARD				C3	C2			CL	COM
			W				W		SC1
S101						BL			NO
							BK
				QH
			BK		W	QHT
								BM
RL3
CONTROL									BK	BK
CIRCUIT			BL	SH		SHT			Y
BOARD
			W		BK
RL4									SC3
						BL
S1
					BK				NC COM
ST	1
	3		CM				Y
RL1
			W						Y
	5
RL6			BR
	7		BL			DM
RL5
		Y
	9					W
			Y
RL7	RL2						TM		Y
					HIGH VOLTAGE TRANSFORMER
	1	G	SC2 COM
S102		NO
	2
			V
	3	Y	SC4 COM			HV FUSE	MAGNETRON 2M-219H(B)
S201 S103		NO
	1
2 1			W			1.14uF
	OT

HIGH VOLTAGE CONDENSER HIGH VOLTAGE RECTIFIER

2x500PF/2x1.5uH

SC1 :	PRIMARY INTERLOCK SWITCH
SC2 :	DOOR SENSING SWITCH
SC3 :	INTERLOCK MONITOR SWITCH
SC4 :	DUMPER SWITCH
QHT :	THERMAL PROTECTOR FOR GRILL
MT :	THERMAL PROTECTOR ON WAVEGUIDE
HAT :	THERMAL PROTECTOR FOR CAVITY
SHT :	THERMAL PROTECTOR FOR CONVEC.
RL1 :	MAIN RELAY
RL2 :	POWER CONTROL RELAY
RL3 :	GRILL HEATER RELAY
RL4 :	CONVEC. HEATER RELAY
RL5 :	FAN MOTOR RELAY
RL6 :	DUMPER MOTOR RELAY

BM : BLOWER MOTOR		WIRING COLOUR
CM	: CONVEC. FAN MOTOR	W	: WHITE
TM	: TURNTABLE MOTOR	G	: GREY
DM	: DUMPER MOTOR	LB : LIGHT BLUE
CL	: OVEN LAMP	BK : BLACK
QH	: GRILL HEATER	V	: VIOLET
SH	: CONVEC. HEATER	BR : BROWN
OT	: OVEN THERMISTOR	Y	: YELLOW
		BL : BLUE

Figure 3

-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-D953 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)		26	87
Roast (450W)		16	53
Simmer(300W)		11	37
Warm (150W)		6	20
Low	(80W)	4	13

-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

it from the control circuit board with an

Approximately 300K ohms

ohm-meter on the highest scale.

Normal Reading:

CONVECTION

Measure the resistance: After removing the lead

HEATER

wires from the convection heater with an

Approximately 46K 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 80K 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 389K 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 120K 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 22K 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,TP-3

and ground or between TP-4, and TP-5. ( See

CONTROL

Test

TP-1

TP-2

TP-3

TP-4/

CIRCUIT

control circuit board on page 24 ).

point

TP-5

BOARD

NOTE

Voltage

-5V

-15V

-30V

2.0V

COMPLETE

Proceed with the check of the step down transformer, to

DC

DC

DC

AC

see if any one of the measured values is different from the

specified values

Measure the resistance between terminals of FPC

connector after removing it from S101. ( See Figure

When

When not

11).

Resistance

touched

touched

NOTE

Value

Less than

More than

- When reconnecting the FPC connector, make sure

the holes on the connector are properly inserted in

1K Ohms

1 MEG Ω

hooks of the plastic fastener in S101.

MATRIX CIRCUIT FOR TOUCH

When checking the "START" key, con-

nect Ohmmeter as illustration below.

KEYBOARD FPC CONNECTOR

TOUCH KEY

Ohm-meter

BOARD

TOP

1A1

2A2

S101 10P

A3

3

A4

7

6

5

4

3

2

1

4

A5

5

C1

UP

GRILL

A.DEF

BAKED

CHICKEN ROAST

6

7

POTATO PIECES

JOINT

C2

8

8

C3

START

DOWN

DUAL

CASSE-

CHOPS/

SNACKS

9C4

COOK

ROLE

STEAKS

9

10C5

STOP/

MICRO

CONVEC

SLOW

BAKED

FROZEN

CAKE/

10

CLEAR

POWER

TEMP

COOK

FISH

PIZZA

PUDDING

TERMINALS OF FPC CONNECTOR

Figure 11

-8-