Sanyo EMP415WS Schematic

File No :

SERVICE MANUAL Microwave Oven EM-P415WS (U.S.A.)

	Product Code No.		437 499 00

CAUTION

WARNING TO SERVICE TECHNICIANS

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 as 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, andconnections.

(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.

(e)A microwave leakage check to verify compliance with the Federal performance standard should be performed on each oven prior to release to the owner.

REFERENCE NO. SM-860251

CAUTION

For microwave energy emission

On every service calls, check for microwave energy emission, must be made according to the following manner.

Measurement of energy emission

Measurement must be made with the microwave oven operating at its maximum output and containing a load of 275±15 milliliters of tap water initially at 20o±5o celsius (68 ±9oF) placed within the cavity at the center.

NOTE : The water container must be a 600 milliliter beaker and made of an electrically none conductive material such as glass or plastic.

The cook tray must be in place when measuring emission.

A properly operating door and seal assembly will normally register emission on greater than 4mW/cm2 to allow for measurement uncertainty with the cooking shelf or tray in place.

All repairs must be performed in such a manner that microwave energy emission are minimal.

Follow the instructions supplied with a detector being used and performed an R.F. emission test around the door front and edges and all edges and vent of the outer case. The cabinet (wrapper) must be in place and the oven fully assembled.

When performing emission survey, with the meter on FAST RESPONSE the movement of a detector probe shall not exceed one (1) inch per second.

In the area emitting the highest reading, switch the meter to SLOW RESPONSE, and take a reading for minimum of three (3) seconds. We recommended the pattern outline shown below when the door surface is surveyed.

NOTE : Periodically check to be sure that the probe tip is not worn or dirty.

The following U.S. standard applies to microwave ovens : 21 CFR 1030.10, Performance Standard for Microwave Ovens.

It requires that the power density of the microwave radiation emitted by a microwave oven shall not exceed five (5) milliwatts per square centimeter at any point 5 centimeter (about 2 inches) or more from the external surface of the oven.

All microwave ovens exceeding the emission level of 4mW/cm2 must be reported to Dept. of Service for microwave ovens and the manufacturer immediately and the owner should be told not to use the microwave oven until it has been repaired completely.

If a microwave oven is found to operate with the door open, report to Dept. of Service, the manufacturer and CDRH* immediately. Also tell the owner not to use the oven.

*CDRH : Center for Device and Radiological Health.

The interlock monitor switch acts as the final safety switch protecting the customer from microwave radiation. If the interlock monitor switch operates to blow the fuse with interlocks failed, you must replace all interlock switches primary and secondary interlock switches and the monitor switch with new ones because the contacts of those interlock switches may be melted and welded together.

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- TABLE OF CONTENTS -

Adjustment Procedures ...................................................	1	Test Procedures and Troubleshooting ....................	4 ~ 10
Specifications ..................................................................	2	Disassembly Instructions .......................................	11	~	14
Power Output Measurement ...........................................	2	Exploded View and Parts List ................................	15	~	20
Precautions and Repair Service Tips ..............................	2	Overall Circuit Diagram ..........................................			21
Circuit Diagram ...............................................................	3

1. ADJUSTMENT PROCEDURES

TO AVOID POSSIBLE EXPOSURE TO MICROWAVE ENERGY LEAKAGE, THE FOLLOWING ADJUSTMENT OF THE INTERLOCK SWITCHES SHOULD BE MADE ONLY BY AUTHORIZED SERVICE PERSONNEL.

The SANYO service center should have the designated detector to measure the microwave energy leakage after the repair or adjustment.

NOTE : Detector to be used at the service center is NARDA 8100, 8200 or the equivalent.

PRIMARY INTERLOCK SWITCH, INTERLOCK MONITOR SWITCH AND DOOR SENSING SWITCH ADJUSTMENT

(Figure 1)

(1)Loosen 2 screws securing the Lever Stopper.

(2)Adjust the Lever Stopper position so that it is pushed forward and pull backward until there is about zero gap between the Latch Lever and the switch body on the Primary Interlock Switch and at the same time there is about zero gap between the Door Latch and the switch body on the Door Sensing Switch when the Door Latch is securely locked.

(3)Tighten the Lever Stopper screws securely.

(4)Make sure the Interlock Monitor Switch closes after the Primary Interlock Switch opens when the Door is opened very slowly, according to “CHECKOUT PROCEDURE FOR SWITCHES” on page 6.

(5)Make sure the Interlock Monitor Switch opens before the Primary Interlock Switch closes when the Door is closed very slowly, according to “CHECKOUT PROCEDURE FOR SWITCHES” on page 6.

(6)Make sure the microwave energy leakage should be no greater than 4mW/cm2 to allow for measurement uncertainty when measured with a detector.

(All service adjustments must be made for minimum microwave energy leakage readings.)

NOTE : If the Interlock Monitor Circuit operates and at the same time the Fuse blows with the Door opened, be sure to replace the Control Circuit Board because Relay 2 on the Control Circuit Board, the Door Sensing Switch and the electric circuit related on the Door Sensing Switch, which act as Secondary Interlock Switch.

Door

Latch

Lever Stopper

Door

Sensing

Switch

Interlock

Monitor

Switch

Screws

Latch	Primary
Lever	Interlock
Figure 1	Switch

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2. SPECIFICATIONS

4. PRECAUTIONS AND REPAIR SERVICE TIPS

Rated Power Consumption ..	1650W.
Microwave Output ................	1100W.
Frequency .............................	2,450MHz±50MHz.
Power Supply ........................	120V±12V, 60Hz.
Rated Current .......................	14 Amp.
Safety Devices .....................	Thermal Fuse open at
	332°F (167°C) for Cavity.
	Thermal Protector open at
	275°F (135°C) for Magnetron.
	Fuse (Cartridge Type 20A)
	Primary Interlock Switch,
	Door Sensing Switch and
	Relay 2.
	Interlock Monitor Switch.
Timer .....................................	Electronic Digital, up to
	99 min. 99 sec.
Overall Dimensions ................	205/8”(W) x 161/2”(D) x 113/8”(H)
Oven Cavity Size ..................	133/4”(W) x 145/8”(D) x 81/4”(H)
Turn Table Diameter ..............	107/8”
Effective Capacity of
Oven Cavity ..........................	1.1 Cubic Feet.
Net Weight ...........................	Approx. 34.1 Lbs.

3. POWER OUTPUT MEASUREMENT

NOTE

The power output specification, 1100W. on this model is measured with IEC measurement. The power output is measured with two (2) liters water is equivalent to 1100W. in measurement with IEC, when measured with the following power output.

(1)Fill two beakers (glass or plastic) with each one liter of tap water (about 20°C) and measure the water temperature. (Use a thermometer with a 1/10 degree gauge).

(2)Place the beakers side by side in the center of the glass tray.

(3)Close the door, set the “TIME” for two minutes. (“200” in the display window). Touch the “START” key and heat the water exactly for two minutes.

(4)Take the beakers out, immediately stir the water and measure the water temperature respectively.

(5)Calculate the temperature rise of water in each beaker. Then calculate the average value of two temperature rises.

Output power can be calculated by the equation : Power Output (W) = 70 x ∆ t

Where ∆ t is an average temperature rise in degrees Centigrade.

(6)Power Output shall be in the following range :

	Average Temperature Rise	Power Output
Minimum	22.9°F (12.7°C)	889W
Maximum	29.3°F (16.3°C)	1141W

(7)Power Output is affected by the line voltage under load. For correct Power Output measurement, the line voltage under load must be 120±1 volts.

PRELIMINARY

A.SINCE NEARLY 2,000 VOLTS EXISTS 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 interlock monitor switch and the door sensing switch operate properly.

(Listen for the clicking sound from the switches). Make sure the interlock monitor switch closes after the primary interlock switch is opens when the door is opened. (See pages 1 and 6).

(b)Make sure the perforated screen and the choke dielectric 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 should be no greater than 4mW/cm2 to allow for measurement uncertainty.

(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 energyleakage.

NOTE : Always keep the seal clean.

(e)Make sure that there are no defective parts in the interlock mechanism.

(f)Make sure there are no defective parts in the microwave generating and transmission assembly. (especially waveguide).

(4)The 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)Waveguide 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.

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5. CIRCUIT DIAGRAM

				SECONDARY INTERLOCK
	SWITCH MADE •	PRIMARY	INTERLOCK	DOOR
		INTERLOCK	MONITOR	SENSING	RELAY 2
		SWITCH	SWITCH	SWITCH
	CONDITION	COM	COM	COM	COM
		NO	NC	NO	NO
	DOOR OPEN		•
	DOOR CLOSE	•		•	•

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6. TEST PROCEDURES AND TROUBLESHOOTING

Filament Windings

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 PROCEDURES

Secondary

Windings

Primary

Windings

Figure 3

COMPONENT		CHECKOUT PROCEDURE	RESULT
	1) Check for resistance : Across the filament		Normal reading :
	terminals of the Magnetron with an Ohm-Meter		Less than 1 Ohm.
	on R x 1 scale.
		Ohm-Meter
		Figure 4
MAGNETRON	2) Check for resistance : Between each filament		Normal reading :
	terminal of the Magnetron and the chassis		Infinite Ohms.
	ground with an Ohm-Meter on highest scale.
		Ohm-Meter
		Figure 5
	1) Measure the resistance :		Normal readings :
	With an Ohm-Meter on R x 1 scale.
	a.	Primary winding :	Approximately 0.31 Ohms.
	b.	Filament winding :	Less than 1 Ohm.
	c.	Secondary winding :	Approximately 67.5 Ohms.
	2) Measure the resistance :		Normal readings :
	With an Ohm-Meter on highest scale.
	a.	Primary winding to ground.	Infinite Ohms.
HIGH-VOLTAGE	b	Filament winding to ground.	Infinite Ohms.
TRANSFORMER
		Ohm-meter
		Figure 6
	Note : Remove varnish of
		measured point.

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COMPONENT	CHECKOUT PROCEDURE				RESULT
	Measure the resistance : Across two terminals		Normal reading :
	with an Ohm-Meter on highest scale.		Momentarily indicates several ohms,
			and gradually returns to 10 Meg-Ohms.
HIGH-VOLTAGE			Abnormal reading :
CAPACITOR			Indicates continuity or 10 Meg-Ohms
including	Ohm-Meter		from the beginning.
BLEEDER
RESISTOR
	Figure 7
	Measure the resistance : Across two terminals		Normal reading :
	with an Ohm-Meter on R x 10,000 scale.		Indicates about the middle position in
			one direction (forward direction) and
			infinite Ohms in the reverse direction,
	Ohm-Meter		using meter which is provided with a
HIGH-VOLTAGE			9 volt battery.
					NOTE
DIODE
			- Some digital meter 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
	Figure 8		in both directions.
	Measure the voltage : Between test point TP-1,
	TP-2 , TP-3 or TP-4 and Ground between TP-5
	and TP-6 (See Control Circuit Board on page 19).		Test	TP-1	TP-2	TP-3		TP-4		TP-5 /
CONTROL			Point							TP-6
CIRCUIT
BOARD	NOTE
			Voltage	-5V	-15V		-25V	-36V		2.0V
				DC	DC		DC	DC		AC
	- Proceed with the check of the Step-Down
	Transformer, to see if any one of the measured
	values is different from the specified values.

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