Amana Rfs18g Service Manual

Microwave Oven Service Manual

RFS18G

CAUTION

BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

RFS18MPS

This device is to be serviced only by properly qualified service personnel. Consult the service manual for proper service procedures to assure continued safety operation and for precautions to be taken to avoid possible exposure to excessive microwave energy.

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, 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.

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.

SAFETY PRECAUTIONS

CONTENTS

(Page)

SAFETY PRECAUTIONS SPECIFICATIONS CAUTIONS

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INSTALLATIONS

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OPERATING INSTRUCTIONS

FEATURES

CONTROL PANEL

COOKING DISPLAYS 4-3

OPERATION

PROGRAMMING

SCHEMATIC DIAGRAM

CIRCUIT DESCRIPTION

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SERVICE INFORMATION

TOOLS AND MEASURING INSTRUMENTS

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Inside front cover

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1-1

2-1 3-1 4-1

4-2

4-4

4-5

4-7

4-8

5-1

MICROWAVE LEAKAGE TEST

MEASUREMENT OF MICROWAVE POWER OUTPUT

DISASSEMBLY AND ADJUSTMENT

INTERLOCK CONTINUITY TEST

COMPONENT TEST PROCEDURE

TROUBLE SHOOTING

EXPLODED VIEW 6-1

SCHEMATIC DIAGRAM OF P.C.B. 7-1

CIRCUIT BOARD

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5-1

5-3

5-7

5-8

5-11

7-2

1-1

This microwave oven is designed for commercial use only.

It is not recommended for buelt-in Installation.

ITEM

MODEL

Power Requirement

Power Output

Microwave Frequency

Magnetron

Timer

Outside Dimensions

Cavity Dimensions

Net Weight

Shipping weight

Control Complement

Nameplate Location

Accessories

DESCRIPTION

RFS18G/RFS18MPS

208/220-240 Volts AC 60 Hz 2,800 Watts (13 A)

Single phase, 3 wire grounded

1,800 Watts full microwave power (IEC60705)

2,450 MHz

2M246

0 ~ 60 min.

64 lbs (approx.) 71 lbs (approx.)

Touch Control System

Clock : 00 ~ 60

Microwave Power for Variable Cooking

Power level

HIGH -------------------------------Full power throughout the cooking time

70% (Med.-High)----------------approx. 70% of Full power

50% (Med.-Low) ---------------approx. 50% of Full power

20% (Low) -----------------------approx. 20% of Full power

Time chart

SPECIFICATIONS

8

16

Back side

¥ DO NOT operate on a 2-wire extension cord during

repair and use.

¥ NEVER TOUCH any oven components or wiring during

operation.

¥ BEFORE TOUCHING any parts of the oven, always

remove the power plug from the outlet.

¥ For about 30 seconds after the oven stops, an electric

charge remains in the high voltage capacitor. When replacing or checking, you must discharge the high voltage capacitor by shorting across the two terminals with an insulated screwdriver.

¥

Remove your watches whenever working close to or

replacing the Magnetron.

¥ DO NOT touch any parts of the control panel circuit. A

resulting static electric discharge may damage this

P.C.B. ¥ NEVER operate the oven with no load. ¥ NEVER injure the door seal and front plate of the oven

cavity. ¥ NEVER put iron tools on the magnetron. ¥ NEVER put anything into the latch hole and the

interlock switches area.

¥ Proper operation of the microwave oven requires that

the magnetron be assembled to the waveguide and cavity. Never operate the magnetron unless it is properly installed.

¥ Be sure that the magnetron gasket is properly

installed around the dome of the tube whenever installing the magnetron.

2-1

CAUTIONS

Unlike other appliances, the microwave oven is high-voltage and high-current equipment. Though it is free from danger in ordinary use, extreme care should be taken during repair.

THE OVEN IS TO BE SERVICED ONLY BY PROPERLY QUALIFIED SERVICE PERSONNEL.

MICROWAVE RADIATION

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 connection. All input and output microwave connections, waveguide, flange, and gasket must be secure never operate the device without a microwave energy absorbing load attached. Never look into an open waveguide or antenna while the device is energized.

Gasket

ANTENNA

COOLING FIN

MAGNETRON CHASSIS GROUND

FILAMENT TERMINALS

MAGNETRON

FILAMENT

TERMINALS

MAGNETRON

Gasket

ANTENNA

COOLING FIN

MAGNETRON

CHASSIS GROUND

INSTALLATIONS

3-1

INSTALLING

1. Empty the microwave oven and clean inside it with a soft, damp cloth. Check for damage such as misaligned door, damage around the door or dents inside the cavity or on the exterior.

2. Put the oven on a counter, table, or shelf that is strong

enough to hold the oven and the food and utensils you put in it. (The control panel side of the oven is the heavy side. Use care when handling.)

3. Do not block the vent and the air intake openings.

Blocking vent or air intake openings can cause damage to the oven and poor cooking results. Make sure the microwave oven legs are in place to ensure proper air flow.

4. The oven should not be installed in any area where

heat and steam are generated, because they may damage the electronic or mechanical parts of the unit. Do not install the oven next to a conventional surface unit or above a conventional wall oven.

5. Use microwave oven in an ambient temperature less

than 104¡F(40¡C).

6. Place the microwave oven as far away as possible

from TV, RADIO, COMPUTER, etc., to prevent interference.

7. Place the microwave oven on a stardy and flat surface.

GROUNDING INSTRUCTIONS

For personal safety, this appliance must be fully grounded at all times.

In the event of an electrical short circuit, grounding reduces the risk of electrical shock. The plug must be plugged into an outlet that is properly installed and grounded.

BEFORE YOU BEGIN, READ THE FOLLOWING INSTRUCTIONS COMPLETELY AND CAREFULLY.

WARNING

Improper use of the grounding plug can result in a risk of electric shock. Do not, under any circumstances, cut or remove the third ground prong from the power cord plug.

A - Allow at least 1

1

/2 inches (3.81 centimeters) of clearance

around top and sides of equipment. Proper air flow around equipment cools electrical components. With restricted air flow, oven may not operate properly and life of electrical parts is reduced.

B - Allow at least 3 inches from door front to edge of countertop to

avoid accidental tipping of oven.

PREFERRED METHOD

ENSURE PROPER GROUND

EXISTS BEFORE USE

A

B

A

B

4-1

OPERATING INSTRUCTIONS

Window Door Screen

Safety Door Lock System

Electronic Control

Door Open Button

Turntable

Rotating Ring

Splatter Shields

FEATURES

CONTROL PANEL

Display

Some items in display can be seen but will not glow.

Pads

Use to enter heating time without changing preprogrammed number pads.

Use to begin heating with preprogrammed times and power levels or to enter times for “Manual Time Entry” cooking.

Use to select power level. Oven can heat at full or reduced power. If oven power level is set to 0% oven does not heat for programmed time. If no power level is selected, oven operates at 100% power.

Use to exit programming mode and stop cooking during cooking cycle.

Use to start “Manual Time Entry” program

Use to automatically increase the programmed time for double quantities.

or restart interrupted cooking cycle. Use to advance to next user option. Use to save times and power levels when programming pads.

TIME ENTRY

Pads 1-0

HOLD 0%, DEFROST 20%, MEDUIM 50%, MED-HI 70%

STOP/RESET

START

QTY2x

8 9 0

Window Door Screen

Electronic Control

Safety Door Lock System

RFS18MPS

HOLD

0%

DEFROST

20%

MEDIUM

50%

MED-HI

70%

TIME

ENTRY

STOP

RESET

START

1 2 3 4 5 6 7 8 9 0

FEATURES

4-2

OPERATING INSTRUCTIONS

FEATURES

CONTROL PANEL

Display

Some items in display can be seen but will not glow.

Pads

Use to enter heating time without changing preprogrammed number pads.

Use to begin heating with preprogrammed

Use to enter times for “Manual Time Entry”

times and power levels or to enter times for “Manual Time Entry” cooking.

cooking.

Use to select power level. Oven can heat at full or reduced power. If oven power level is set to 0% oven does not heat for programmed time. If no power level is selected, oven operates at 100% power.

Use to exit programming mode and stop cooking during cooking cycle.

Use to start “Manual Time Entry” program

Use to automatically increase the programmed time for double quantities.

or restart interrupted cooking cycle. Use to advance to next user option. Use to save times and power levels when programming pads.

RFS18G

TIME ENTRY

DIAL

Pads 1-0

POWER LEVEL

STOP/RESET

START

QTY2x

9 0

Window Door Screen

Electronic Control

Safety Door Lock System

POWER

LEVEL

QTY

2X

TIME

ENTRY

+

-

CONTROL PANEL

Window Door Screen

Electronic Control

Safety Door Lock System

Display

Some items in display can be seen but will not glow.

Pads

8 9 0

TIME ENTRY

Pads 1-0

HOLD 0%, DEFROST 20%, MEDUIM 50%,

STOP/RESET

START

QTY2x

Use to enter heating time without changing preprogrammed number pads.

Use to begin heating with preprogrammed times and power levels or to enter times for “Manual Time Entry” cooking.

Use to select power level. Oven can heat at full or reduced power. If oven power level is set to 0% oven does not heat for programmed time. If no power level is selected, oven operates at 100% power.

Use to exit programming mode and stop cooking during cooking cycle.

Use to start “Manual Time Entry” program or restart interrupted cooking cycle. Use to advance to next user option. Use to save times and power levels when programming pads.

Use to automatically increase the programmed time for double quantities.

4-3

Cooking Displays

Shows when power is connected to oven. Open and close door to clear.

READY shows when oven control will accept entries. Appears after oven door is opened and closed.

88:88 shows heating time. When more than 1 heating stage is programmed, total time for all stages displays.

COOK shows when oven is operating.

20 indicates the microwave power level used. If power level does not show, oven is heating at 100% power.

Programming Displays

Indicates programming mode. See ÒProgrammingÓ section of manual for programming procedure.

Indicates programming user options mode. See ÒUser OptionsÓ section of manual for programming procedure.

Cooking Displays

Shows when power is connected to oven. Open and close door to clear.

READY shows when oven control will accept entries. Appears after oven door is opened and closed.

33:33 shows heating time. When more than 1 heating stage is programmed, total time for all stages displays.

COOK shows when oven is operating. 20 indicates the microwave power level used. If power level

does not show, oven is heating at 100% power.

Cooking DisplaysCooking DisplaysCooking Displays

Programming Displays

Indicates programming mode. See “Programming” section of manual for programming procedure.

Indicates programming user options mode. See “User Options” section of manual for programming procedure.

Programming DisplaysProgramming DisplaysProgramming Displays

4-4

Operation

Pads

1 2 3 4 5 6 7 8 9 0

Heating Times

10 sec. 20 sec. 30 sec. 45 sec. 1 min. 1:30 min. 2 min. 3 min. 4 min. 5 min.

Pads

01 02 03 04 05 06 07 08 09 10

1. Press Pad.

CAUTION

Interrupting Operation

• Open oven door to interrupt operation. Oven fan continues to operate. Close door and press START pad to resume oven operation.

• Press STOP/RESET pad to interrupt operation. Display continues to show countdown time. Press START pad to resume oven operation and countdown timing.

Canceling Mistakes

• If oven is operating, press STOP/RESET pad once to

stop oven, then again to clear display.

• If oven door is open and time shows in display, close oven door and press STOP/RESET pad to clear display.

Operating Preprogrammed Pads

Oven has 10 ~ 20 preprogrammed number pads. Instructions are written for factory programmed ovens. Ovens that are reprogrammed can respond differently than described below.

1. Open oven door , place food in oven, and close oven

door

• If pad is not pressed in 30 seconds, open and close oven door again.

2. Press desired number pad.

• Oven operates and time counts down.

3. Oven stops heating and oven signal sounds when heating timing elapses.

Operating QTY 2X Pads

QTY

2X

2. Press desired number pad

• Example : press + = 18 sec.

Preprogrammed Times and Cook Level

All preprogrammed pads arrive set at full power.

Option: Single Digit

Pads

11 12 13 14 15 16 17 18 19 20

Heating Times

10 sec. 20 sec. 30 sec. 45 sec. 1 min. 1:30 min. 2 min. 3 min. 4 min. 5 min.

Heating Times

20 sec. 40 sec. 1 min. 1:30 min. 2 min. 3 min. 4 min. 6 min. 8 min. 10 min.

Option: Double Digit

Manual Time Entry

Manual Time Entry feature allows the operator to enter time and power levels, and heat without changing the preprogrammed pads.

1. Open oven door, place food in oven, and close door.

• Display shows "READY".

• If pad is not pressed in 30 seconds, open and close oven door again.

2. Press TIME ENTRY pad.

• Display shows "00:00".

3. Press number pads to enter desired cooking time.

• For example, to heat for 2 minutes 30 seconds,

press 2, 3, and 0 pads.

4. Press desired power level pad to change power level.

• If a power level pad is not pressed, oven defaults to 100% power.

• For example, pressing MEDIUM 50% pad sets oven to 50% power.

• Display shows current power level if other than 100 percent power.

5. Press START pad.

• Oven operates and time counts down.

6. Oven stops heating and oven signal sounds when heating timing elapses.

QTY

2X

1

To avoid fire, do not dry newspapers or clothes in microwave oven.

4-5

PROGRAMMING

Preprogrammed Number Pads

Oven has 10 preprogrammed number pads. Follow instructions below to program heating times and power levels for customized cooking.

1. Open oven door. ¥ If door is closed or STOP/RESET pad is pressed

before finishing programming sequence, oven exits programming mode.

2. Press and hold pad 1 for approximately 5 seconds. ¥ After 5 seconds, signal sounds. Display shows

ÒPROGRAMÓ indicating program mode..

3. Press desired number pad. ¥ Display shows heating time, ÒCOOK LEVELÓ and

power level if other than 100 percent power.

4. Press number pads to enter desired cooking time. ¥ For example, to heat for 2 minutes 30 seconds,

press 2, 3, and 0 pads.

5. Press desired power level pad to change power level. ¥ If a power level pad is not pressed, oven defaults to

100% power.

¥ For example, pressing MEDIUM 50% pad sets oven

to 50% power.

¥ Display shows current power level if other than 100%

power.

6. Press START pad to save new heating time and power level in oven memory. ¥ Repeat step 3-6 to program additional pads.

7. Press STOP/RESET pad or close oven door to exit programming mode.

Multiple Heating Stages

Follow instructions below to program oven to perform 3 consecutive heating cycles without interruption.

1. Open oven door. ¥ If door is closed or STOP/RESET pad is pressed

before finishing programming sequence, oven exits programming mode.

2. Press pad 1 for approximately 5 seconds. ¥ After 5 seconds, signal sounds.

3. Press desired number pad. ¥ Display shows heating time and preprogrammed

number.

4. Press number pads to enter desired cooking time. ¥ For example, to heat for 2 minutes 30 seconds,

5. Press desired power level pad to change power level. ¥ If a power level pad is not pressed, oven defaults to

100% power.

¥ For example, pressing MEDIUM 50% pad sets oven

to 50% power.

¥ Display shows current power level if other than 100

percent power.

6. Press TIME ENTRY pad ¥ Display briefly shows ÒSTAGE 2Ó . Then cook time

and power level for stage show in display.

¥ Repeat steps 5-6 to create additional stages.

7. Press START pad to save new heating time and power level in oven memory.

8. Press STOP/RESET pad or close oven door to exit programming mode.

4-6

User Options

Follow the instructions below to customized the microwave ovenÕs operation. End-of-cycle signal, maximum heating time and other options can be changed to meeting your cooking needs.

1. Open oven door. ¥ If door is closed or STOP/RESET pad is pressed

before finishing programming sequence, oven exits programming mode.

2. Press and hold pad 2 for approximately 5 seconds. ¥ After 5 seconds, signal sounds. Display shows

ÒOPTIONÓ.

3. Press number pad that matches desired option. ¥ ÒOPÓ represents optional program mode, first number

represents option number and second number represents functions currently selected for option.

4. Press START pad to advance to next option. See table for options.

5. Press number pad (0,1-3) to change option.

6. Press START pad to save changes. ¥ Repeat steps 4-6 to change additional options.

7. Press STOP/RESET pad or close oven door to exit programming mode.

Optional Program Pad Option Indicator Number Selected

SCHEMATIC DIAGRAM

4-7

NOTICE: SINCE THIS IS BASIC SCHEMATIC DIAGRAM, THE VALUES OF COMPONENTS AND

SOME PARTIAL CONNECTIONS ARE SUBJECT TO CHANGE FOR IMPROVEMENT.

IMPORTANT SAFETY NOTE: THE SHADED AREAS ON THIS SCHEMATIC DIAGRAM INCORPORATE SPECIAL FEATURES

IMPORTANT FOR PROTECTION FROM MICROWAVE RADIATION, FIRE, ELECTRICAL SHOCK, AND

HAZARDS. WHEN SERVICING IT IS ESSENTIAL THAT ONLY MANUFACTURER'S SPECIFIED PARTS

BE USED FOR THE CRITICAL COMPONENTS IN THE SHADED AREAS OF THE SCHEMATIC DIAGRAM.

CIRCUIT DESCRIPTION

GENERAL DETAILS

• The low voltage transformer supplies the necessary voltage to the micom controller when power cord is plugged in.

• When the door is closed, the primary switch is ON, the

secondary switch is ON, and the monitor switch opens (contact COM and NO).

WHEN SELECTING COOKING POWER LEVEL AND TIME

• The micom controller memorizes the function you set.

• The time you set appears in the display window.

• Each indicator light turns on to indicate that the stage

has been set.

WHEN TOUCHING THE START PAD

• The coil of the relay is energized by the micom

controller.

• Power input is supplied to the high voltage transformer

through the fuse to top primary switch and relay 3 (208V : relay 4) and the btm primary switch and realy 5 (208V : relay 6).

• Stirrer fan rotates.

• A high voltage of approximately 2100 volts AC is generated in the secondary of the high voltage transformer which is increased by the action of the high voltage diode and charging of the high voltage capacitor.

• The negative 4,000 Volts DC is applied to the filament of the magnetron.

WHEN THE OVEN IS SET AT ANY LEVEL EXCEPT MAXIMUM.

• The micom controller controls the ON-OFF time of relay 3 and relay 5 (208V : relay 4 & relay 6) by the applied signal to vary the average output power of microwave oven as POWER LEVEL. (refer to page 1-1)

• One complete cycle of relay 3 is 12.

WHEN THE DOOR IS OPENED DURING COOKING

• Between the btm primary switch and relay 5

(208V : relay 6) and top primary switch and relay 3 (208V : relay 4) cut off the primary winding

voltage of the high voltage transformer.

• ON-OFF of relay 3 relay 5 (208V : relay 4 and relay 5)

is coupled electrically with opening

and closing of the secondary switch.

• When the door is opened, the secondary switch is opened and when the door is closed, the secondary switch is closed.

• The cooking time stops counting down.

• Relay stops functioning.

• As the door is opened, if the contact of top primary switch and relay 3 switch and relay 5 fail to open, the fuse opens

surge caused by the monitor switch activation, which

in turn stops magnetron oscillation.

(208V : relay 4) (208V : relay 6)

due to the large current

and the btm primary and/or secondary switch

• The fan motor rotates and cools the magnetron by blowing the air (coming from the intake on the baseplate).

• The air is also directed into the oven to exhaust the vapor in the oven through the upper plate.

• Cooking time starts counting down.

• 3.3 volts AC is generated from the filament winding of the high voltage transformer. This 3.3 volts is applied to the magnetron to heat the magnetron filament through two noise-preventing choke coils.

4-8

CAUTIONS

¥ Be sure to check microwave leakage prior to

servicing the oven if the oven is operative prior to servicing.

¥ The service personnel should inform the

manufacturer, importer, or assembler of any certified oven unit found to have a microwave emission level in excess of 5 mW/cm2and should

repair any unit found to have excessive emission levels at no cost to the owner and should ascertain the cause of the excessive leakage. The service personnel should instruct the owner not to use the unit until the oven has been brought into compliance.

¥ If the oven operates with the door open, the service

personnel should:

- Tell the user not to operate the oven.

- Contact the manufacturer and CDRH (Center for Devices and Radiological Health) immediately.

NOTE: Address on CDRH

Office of Compliance(HFZ-312) Center for Devices and Radiological Healthe 1390, Piccard Drive, Rockville. MD 20850

¥ The service personnel should check all surface and

vent openings for microwave leakage.

¥ Check for microwave leakage after every servicing. The

power density of the microwave radiation leakage emitted by the microwave oven should not exceed 4 mW/cm2. Always start measuring of an unknown field to assure safety for operating personnel from radiation leakage.

MEASURING MICROWAVE ENERGY LEAKAGE

¥ Pour 275±15cc of 20±5¡C(68±9¡F) water in a beaker

which is graduated to 600 cc, and place the beaker on the center of the turntable.

¥ Set the energy leakage monitor to 2,450 MHz and

use it following the manufacturer's recommended test procedure to assure correct result.

¥ When measuring the leakage, always use the 2-inch

(5cm) spacer supplied with the probe. ¥ Operate the oven at its maximum output. ¥ Measure the microwave radiation using and

electromagnetic radiation monitor by holding the

probe perpendicular to the surface being measured

Move probe along shaded area

Probe scanning speed

Less than 2.5 cm/sec

( 1in/sec)

5-1

SERVICE INFORMATION

TOOLS AND MEASURING INSTRUMENTS

MICROWAVE LEAKAGE TEST

NECESSARY TOOLS

Tools normally used for TV servicing are sufficient. Standard tools are listed below.

¥ Diagonal pliers ¥ Long nose pliers ¥ Phillips screwdriver ¥ Flat blade screwdriver ¥ Wrench (size 5mm) ¥ Nutdriver (size 5mm) ¥ Adjustable wrench ¥ Soldering iron ¥ Solder ¥ Vinyl insulation tape ¥ Polishing cloth

NECESSARY MEASURING INSTRUMENTS

¥ TESTER (VOLTS-DC, AC, Ohmmeter) ¥ Microwave survey meter

- Holaday HI-1500 HI-1501

- Narda 8100

8200 ¥ Inch scale ¥ 600 cc non conductive material beaker (glass or plastic),

inside diameter: approx. 8.5 cm (3

1

/2 in.)

¥ Cylindrical and made of borosilicate glass vessel.

max. thickness: 3 mm outside diameter: approx. 190mm height: approx. 90mm

¥ Glass thermometer: 100¡C or 212¡F (1 deg scale)

MEASUREMENT WITH OUTER CASE REMOVED

¥ When you replace the magnetron, measure for

microwave energy leakage before the outer case is installed and after all necessary components are replaced or adjusted.

Special care should be taken in measuring the

following parts. (Circled area of Fig. below)

- Around the magnetron

- The waveguide

MEASUREMENT WITH A FULLY ASSEMBLED OVEN

¥ After all components, including the outer case, are fully

assembled, measure for microwave energy leakage around the door viewing window, the exhaust opening, and air inlet openings.

¥ Microwave energy leakage must not exceed the values

prescribed below.

NOTE: Leakage with the outer case removed less than

5 mW/cm.sq. Leakage for a fully assembled oven (Before the latch switch (primary) is interrupted) with the door in a slightly opened position-less than 2 mW/cm.sq.

NOTES WHEN MEASURING

¥ Do not exceed meter full scale deflection. ¥ The test probe must be removed no faster than

1 inch/sec (2.5 cm/sec) along the shaded area, otherwise a false reading may result.

¥ The test probe must be held with the grip portion of the

handle.

A false reading may result if the operator's hand is

between the handle and the probe.

¥ When testing near a corner of the door, keep the probe

perpendicular to the surface making sure the probe horizontally along the oven surface; this may possibly cause probe damage.

RECORD KEEPING AND NOTIFICATION AFTER MEASUREMENT

¥ After adjustment and repair of any microwave energy

interruption or microwave energy blocking device, record the measured values for future reference. Also enter the information on the service invoice.

¥ The microwave energy leakage should not be more

than 4 mW/cm.sq. after determining that all parts are in good condition, functioning properly and genuine replacement parts which are listed in this manual have been used.

¥ At least once a year, have the electromagnetic energy

leakage monitor checked for calibration by its manufacturer.

5-2

WARNING : AVOID CONTACTING ANY

HIGH VOLTAGE PARTS

MEASUREMENT OF MICROWAVE POWER OUTPUT

securing screw

Remove the screw

Lift up and pull out control panel

• Microwave power output measurement is made with the microwave oven supplied at its rated voltage and operated at its maximum microwave power setting with a load of (1000±5) g of potable water.

• The water is contained in a cylindrical borosilicate glass vessel having a maximum material thickness of 3 mm and an outside diameter of approximately 190mm.

• The oven and the empty vessel are at ambient temperature prior to the start of the test.

• The initial temperature (T1) of the water is (10±2)°C It is measured immediately before the water is added to the vessel. After addition of the water to the vessel, the load is immediately placed on the center of the ceramic plate which is in the lowest position and the microwave power switched on.

• The time T for the temperature of the water to rise by a value ∆ T of (10±2)°K is measured, where T is the time

in seconds and ∆T is the temperature rise. The initial and final water temperatures are selected so that the maximum difference between the final water temperature and the ambient temperature is 5°K.

• The microwave power output P in watts is calculated from the following formula :

is measured while the microwave generator is operating at full power. Magnetron filament heat-up time is not included. (about 3 sec)

• The water is stirred to equalize temperature throughout the vessel, prior to measuring the final water temperature.

• Stirring devices and measuring instruments are selected in order to minimize addition or removal of heat.

DISASSEMBLY AND ADJUSTMENT

P =

WATER LOAD

4187 x (∆T)

T

CERAMIC PLATE

A. OUTER CASE REMOVAL

1) Disconnect the power supply cord from the outlet.

2) Remove the screws from the rear of the case. The outer case must be moved backward to be lifted off.

B. POWER SUPPLY CORD

1) Remove the outer case.

2) Disconnect two terminals, and remove one screw of the ground terminal.

C. CONTROL PANEL ASSEMBLY RMOVAL

1) Open the door.

2) Remove the screw for securing the control panel.

3) Disconnect the leadwire from RELAY of the PCB

SUB ASS’Y.

4) Disconnect the leadwire from connector (CN1) of the PCB SUB ASS’Y.

5) Lift up and pull out control panel assembly carefully

from the cavity.

CAUTION: DISCHARGE THE HIGH VOLTAGE

CAPACITOR BEFORE SERVICING

(refer to page 2-1)

Remove the screw

securing screw

ground screw

Lift up and pull out control panel

5-3

D. PCB ASSEMBLY REMOVAL

1) Remove the control panel assembly from the cavity. (Refer to control panel assembly removal on previous page.)

2) Remove screws which hold the PCB SUB ASSÕY to the control panel.

3) Disconnect the flat cable from the PCB SUB ASSÕY and take off the PCB SUB ASSÕY

E. DOOR MAIN ASSEMBLY REMOVAL

1) Open the door.

2) Remove the choke cover cap very carefully with a flat-blade

screwdriver.

CAUTION: Be careful not to damage door seal plate

by screwdriver.

3) Lift up and push the door.

NOTE:

1. After replacing the door, be sure to check that the

primary switch, monitor switch, and secondary switch operate normally.

2. After replacing the door, check for microwave energy

leakage with a survey meter. Microwave energy must be below the limit of 4 mW/cm2. (with a 275 ml water load)

3. When mounting the door assembly to the oven

assembly, be sure to adjust the door assembly parallel to the chassis. Also adjust so the door has no play between the inner door surface and oven frame assembly. If the door assembly is not mounted properly, microwaves may leak from the clearance between the door and the oven.

5-4

Door seal plate

Remove door

Remove choke cover

Spacer

SpacerSpacerSpacerSpacer

Control Panel

PCB Sub Asm

Door seal plate

Remove door

Remove choke cover

Control Panel

Key Membrane

PCB Sub Asm

Button Spring

Door Open Button

Release Lever

5-5

F. MAGNETRON REMOVAL

1) Disconnect the leadwire from the magnetron.

2) Carefully remove the mounting screws holding the magnetron and the waveguide.

3) Remove the magnetron ASSÕY until the tube is clear from the waveguide.

NOTE:

1. When removing the magnetron, make sure its

dome does not hit any adjacent parts, or it may be damaged.

2. When replacing the magnetron, be sure to install

the magnetron gasket in the correct position and be sure that the gasket is in good condition.

3. After replacing the magnetron, check for microwave

leakage with a survey meter around the magnetron. Microwave energy must be below the limit of 5

mW/cm2. (With a 275 ml. water load).

Make sure that gasket is rigidly attached to the magnetron. To prevent microwave leakage, tighten

the mounting screws properly, making sure there is no gap between the waveguide and the magnetron.

G. REMOVING THE TURNTABLE MOTOR

1) Remove the turntable and rotating ring.

2) Lay the unit down on its back.

3) Remove the turntable motor cover. The turntable base cover is easily removed by pinching the eight parts with a wire cutting.

4) Disconnect the leadwire from the turntable motor terminals.

5) Remove the screw securing the turntable motor to the oven cavity ASSÕY

6) After repairing the motor, rotate the removed turntable motor cover.

7) Fit the turntable motor coverÕs projecting part to the base plate slit.

NOTE:

1. Remove the wire lead from the turntable motor

VERY CAREFULLY.

2. Be sure to grasp the connector, not the wires, when

removing.

Magnetron

Air Duct

Waveguide

Magnetron Gasket Magnetron

Dome

Waveguide Bracket

Magnetron

F. MAGNETRON REMOVAL

1) Disconnect the leadwire from the magnetron.

2) Remove the duct ASS'Y.

3) Carefully remove the mounting screws holding the magnetron and the waveguide.

4) Remove the magnetron ASS’Y until the tube is clear from the waveguide.

NOTE:

1. When removing the magnetron, make sure its dome does not hit any adjacent parts, or it may be damaged.

2. When replacing the magnetron, be sure to install the magnetron gasket in the correct position and be sure that the gasket is in good condition.

3. After replacing the magnetron, check for microwave leakage with a survey meter around the magnetron. Microwave energy must be below the limit of 5

mW/cm

2

. (With a 275 ml. water load).

Make sure that gasket is rigidly attached to the magnetron. To prevent microwave leakage, tighten

the mounting screws properly, making sure there is no gap between the waveguide and the magnetron.

G. REMOVING THE BOTTOM STIRRER FAN MOTOR

1) Lay the unit down on its back.

2) Remove the screw securing the base cover.

3) Disconnect the leadwire from the stirrer fan motor terminals.

4) Remove the screw securing the stirrer fan motor to the oven cavity ASS’Y

5) After repairing the motor, replace the removed base cover.

NOTE:

1.

Remove the wire lead from the stirrer fan motor VERY CAREFULLY.

2. Be sure to grasp the connector, not the wires, when removing.

Stirrer Fan Motor

Base cover

Wire Leads

Seal water

Wire Leads

Turntable Motor

H. HIGH VOLTAGE TRANSFORMER

Suction Guide

H. HIGH VOLTAGE TRANSFORMER

REMOVAL

1) Discharge the high voltage capacitor.

2) Disconnect the leadwire from magnetron, high voltage transformer, and capacitor.

3) Remove the screw holding the high voltage transformer to the baseplate.

I. BLOWER MOTOR ASSEMBLY REMOVAL

1) Discharge the leadwire from blower motor.

5) Remove the screw holding the duct Ass'y.

4) Romove the screw holding the high voltage capacitor

bracket.

2) Remove the two screws holding the blower motor

bracket to the upper plate.

3) Remove the screw holding the blower motor bracket

to the back cover.

J. HIGH VOLTAGE CAPACITOR AND

DIODE REMOVAL

1) Discharge the high voltage capacitor.

2) Disconnect the leadwire from

high voltage capacitor.

3) Remove the screw holding the

high voltage diode

earth screw.

4) Remove the screw holding the high voltage capacitor bracket.

K. INTERLOCK SYSTEM

1) INTERLOCK MECHANISM The door lock mechanism is a device which has

been specially designed to eliminate completely microwave activity when the door is opened during cooking and thus to prevent the danger resulting from the microwave leakage.

2) MOUNTING OF THE PRIMARY/MONITOR/

SECONDARY SWITCHES TO THE LATCH BOARD

3) INSTALLATION AND ADJUSTMENT OF THE

LATCH BOARD TO THE OVEN ASSEMBLY

• Mount the latch b oard to the oven assembly.

• Adjust the latch board in the arrow direction so that

oven door will not have any play in it when the door is closed.

• Tighten the mounting screw.

• Check for play in the door by pushing the door

release button. Door movement should be less than 0.5 mm. (1/64 inch)

Don't push the door release button while making this adjustment. Make sure that the latch moves smoothly after adjustment is completed and that the screws are tight. Make sure the primary, monitor, and secondary switches operate properly by following the continuity test procedure.

PRIMARY SWITCH

ADJUSTMENT DIRECTION

MONITOR SWITCH

SECONDARY SWITCH

Blower Motor ASS'Y

H.V

bracket

Transformer

H.V Transformer

capacitor

REMOVAL

1) Discharge the high voltage capacitor.

2) Disconnect the leadwire from magnetron, high voltage transformer, and capacitor.

3) Remove the screw holding the high voltage transformer to the baseplate.

I. FAN MOTOR ASSEMBLY REMOVAL

1) Discharge the high voltage capacitor.

2) Disconnect the leadwire from fan motor, noise filter and high voltage capacitor.

3) Remove the two screws holding the the suction guide ASS’Y to the oven cavity and remove the high voltage diode earth screw.

4) Remove the two screws holding the fan motor ASS’Y to the suction guide ASS’Y.

J. HIGH VOLTAGE CAPACITOR AND

DIODE REMOVAL

1) Discharge the high voltage capacitor.

2) Disconnect the leadwire from fan motor, noise filter and high voltage capacitor.

3) Remove the screw holding the suction guide ASS’Y to the oven cavity and remove the high voltage diode earth screw.

4) Remove the screw holding the high voltage capacitor bracket.

Fan Motor ASS'Y

K. INTERLOCK SYSTEM

1) INTERLOCK MECHANISM The door lock mechanism is a device which has

been specially designed to eliminate completely microwave activity when the door is opened during cooking and thus to prevent the danger resulting from the microwave leakage.

2) MOUNTING OF THE PRIMARY/MONITOR/ SECONDARY SWITCHES TO THE LATCH BOARD

3) INSTALLATION AND ADJUSTMENT OF THE LATCH BOARD TO THE OVEN ASSEMBLY

• Mount the latch b oard to the oven assembly.

• Adjust the latch board in the arrow direction so that

oven door will not have any play in it when the door is closed.

• Tighten the mounting screw.

• Check for play in the door by pushing the door

release button. Door movement should be less than 0.5 mm. (1/64 inch)

Don't push the door release button while making this adjustment. Make sure that the latch moves smoothly after adjustment is completed and that the screws are tight. Make sure the primary, monitor, and secondary switches operate properly by following the continuity test procedure.

ADJUSTMENT DIRECTION

H.V. Transformer

H.V. Diode

Suction Guide

H.V. Capacitor

5-6

SECONDARY SWITCH

MONITOR SWITCH

PRIMARY SWITCH

A. PRIMARY INTERLOCK SWITCH TEST

When the door release button is depressed slowly with the door closed, an audible click should be heard at the same time or successively at intervals. When the button is released slowly, the latches should activate the switches with an audible click. If the latches do not activate the switches when the door is closed, the switches should be a adjusted in accordance with the adjustment procedure. Disconnect the wire lead from the primary switch. Connect the ohmmeter leads to the common (COM) and normally open (NO) terminal of the switch. The meter should indicate an open circuit in the door open condition. When the door is closed, the meter should indicate a closed circuit. When the primary switch operation is abnormal, make the necessary adjustment or replace the switch only with the same type of switch.

B. SECONDARY INTERLOCK SWITCH TEST

Disconnect the wire lead from the secondary switch. Connect the ohmmeter leads to the common (COM) and normally open (NO) terminals of the switch. The meter should indicate a open circuit in the door open condition. When the door is closed, meter should indicate an closed circuit. When the secondary switch operation is abnormal, make the necessary adjustment or replace the switch only with the same type of switch.

C. MONITOR SWITCH TEST

Disconnect the wire lead from the monitor switch. Connect the ohmmeter leads to the common (COM) and normally closed (NC) terminals of the switch. The meter should indicate closed circuit in the door open condition. When the door is closed, meter should indicate an open circuit. When the monitor switch operation is abnormal, replace with the same type of switch.

NOTE: After repairing the door or the interlock system, it is necessary to do this continuity test before operating the oven.

5-7

WARNING : FOR CONTINUED PROTECTION AGAINST EXCESSIVE RADIATION

EMISSION, REPLACE ONLY WITH IDENTICAL REPLACEMENT PARTS.

TYPE NO. SZM-V 16-FD-63 OR V-16-3C 25 FOR PRIMARY SWITCH TYPE NO. SZM-V 16-FD-62 OR V-16-2C 25 FOR MONITOR SWITCH TYPE NO. SZM-V 16-FD-63 OR V-16-3C 25 FOR SECONDARY SWITCH

COMPONENTS TEST PROCEDURE RESULTS

SWITCHES Check for continuity of the Door Door (Wire leads removed) switch with an Ohm-meter open closed

Primary Switch

Monitor Switch

Secondary Switch

NOTE : After checking for the continuity of switches, make sure that they are

connected correctly.

INTERLOCK CONTINUITY TEST

COM

NO

NC

NO

COMPONENT TEST PROCEDURE

CAUTIONS

1. DISCONNECT THE POWER SUPPLY CORD FROM THE OUTLET WHENEVER REMOVING THE

1. DISCONNECT THE POWER SUPPLY CORD FROM THE OUTLET WHENEVER REMOVING THE OUTER CASE FROM THE UNIT. PROCEED WITH THE TEST ONLY AFTER DISCHARGING THE HIGH

OUTER CASE FROM THE UNIT. PROCEED WITH THE TEST ONLY AFTER DISCHARGING THE HIGH VOLTAGE CAPACITOR AND REMOVING THE WIRE LEADS FROM THE PRIMARY WINDING OF THE

VOLTAGE CAPACITOR AND REMOVING THE WIRE LEADS FROM THE PRIMARY WINDING OF THE HIGH VOLTAGE TRANSFORMER. (SEE PAGE 2-1)

HIGH VOLTAGE TRANSFORMER. (SEE PAGE 2-1)

2. ALL OPERATIONAL CHECKS WITH MICROWAVE ENERGY MUST BE DONE WITH A LOAD (1 LITER

2. ALL OPERATIONAL CHECKS WITH MICROWAVE ENERGY MUST BE DONE WITH A LOAD (1 LITER OF WATER IN CONTAINER) IN THE OVEN.

OF WATER IN CONTAINER) IN THE OVEN.

COMPONENTS

HIGH VOLTAGE

HIGH VOLTAGE TRANSFORMER

TRANSFORMER (Wire leads removed)

(Wire leads removed)

TEST PROCEDURE RESUL TS

FILAMENT WINDING

1. Measure the resistance. (Ohm-meter scale: Rx1 and Rx100)

• Primary winding

• Secondary winding

• Filament winding

SECONDARY TERMINAL

PRIMARY TERMINAL

208V 220-240 V

208V

Approx.: 0. 0.9 ~ 1.1 ohm

Approx.: 0. Approx.: 70 ~ 80 ohm

Approx.: 70 ~ 8 Less than: 1 ohm

8 ~ 1.0 ohm

8 ~ 1.0

8 1.0

7

70 ~ 80 ohm

MAGNETRON (Wire leads removed)

2. Measure the resistance. (Ohm-meter scale: Rx1000)

• Primary winding to ground

• Filament winding to ground

1. Measure the resistance. (Ohm-meter scale: Rx1)

• Filament terminal

2. Measure the resistance. (Ohm-meter scale: Rx1000)

• Filament to chassis

5-8

Normal: Infinite Normal: Infinite

Normal: Less than 1 ohm

Normal: Infinite

5-9

COMPONENTS TEST PROCEDURE RESULTS

HIGH VOLTAGE CAPACITOR

HIGH VOLTAGE DIODE

NOTE : Some inexpensive meters may indicate infinite resistance in both direction.

Measure the resistance. (Ohm-meter scale: Rx1000) ¥ Terminal to terminal.

Measure the resistance. (Ohm-meter scale: Rx1000) ¥ Terminal to case.

Measure the continuity (Forward). (Ohm-meter scale: Rx10000)

Measure the continuity (Reverse). (Ohm-meter scale: Rx10000)

Normal: Momentarily indicates

several ohms, and then gradually returns to infinite.

Normal: Infinite.

Normal: Continuity. Abnormal: Infinite.

Normal: Infinite. Abnormal: Continuity.

NOTE: When testing the magnetron, be sure to install the magnetron gasket

in the correct position and be sure that the gasket is in good condition.

Antenna

Gasket

Chassis

Filament

Antenna

Gasket

Chassis

Filament

COMPONENTS TEST PROCEDURE RESULTS

208V: RELAY 4 / RELAY 6 220-240V: RELAY 3 / RELAY 5

BLOWER MOTOR

(Wire leads removed)

Check for continuity of relay 3 an ohm-meter. (Remove wire leads from relay 2 and operate the unit.)

Relay 3

Measure the resistance. (Ohm-meter scale: R x 100)

208V

POWER LEVEL

1 3 sec 9 sec 2 4 sec 8 sec 3 5 sec 7 sec 4 6 sec 6 sec 5 7 sec 7 sec 6 8 sec 4 sec 7 9 sec 3 sec 8 10 sec 2 sec 9 11 sec 1 sec

10 12 sec 0 sec

Normal: Approx. 208V: 28~31 ohm

220-240V: 31~35

ohm

Abnormal: Infinite or several

K-ohm.

220-240V

0V

STIRRER

MOTOR (Wire leads removed)

NOTE : • A MICROWAVE LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS

SERVICED FOR ANY REASON.

• MAKE SURE THE WIRE LEADS ARE IN THE CORRECT POSITION.

• WHEN REMOVING THE WIRE LEADS FROM THE PARTS, BE SURE TO GRASP THE CONNECTOR, NOT THE WIRES.

Measure the resistance. (Ohm-meter scale: R x 1)

Normal: Approx. 12~14 kohm

Abnormal: Infinite or several

ohm.

5-10

TROUBLE SHOOTING

WHEN YOU GET A COMPLAINT FROM YOUR CUSTOMER, EVALUATE THE COMPLAINT CAREFULLY. IF

WHEN YOU GET A COMPLAINT FROM YOUR CUSTOMER, EVALUATE THE COMPLAINT CAREFULLY. IF THE FOLLOWING SYMPTOMS APPLY, PLEASE INSTRUCT THE CUSTOMER IN THE PROPER USE OF THE

THE FOLLOWING SYMPTOMS APPLY, PLEASE INSTRUCT THE CUSTOMER IN THE PROPER USE OF THE

THE FOLLOWING SYMPTOMS APPLY, PLEASE INSTRUCT THE CUSTOMER IN THE PROPER USE OF THE MICROWAVE OVEN. THIS CAN ELIMINATE AN UNNECESSARY SERVICE CALL.

MICROWAVE OVEN. THIS CAN ELIMINATE AN UNNECESSARY SERVICE CALL.

CAUTIONS

1. Check grounding before checking for trouble.

2. Be careful of the high voltage circuit.

3. Discharge the high voltage capacitor. (See page 2-1)

4. When checking the continuity of the switches or of the high voltage transformer, disconnect one lead wire

4. When checking the continuity of the switches or of the high voltage transformer, disconnect one lead wire from these parts and then check continuity with the AC plug removed. To do otherwise may result in a

from these parts and then check continuity with the AC plug removed. To do otherwise may result in a

from these parts and then check continuity with the AC plug removed. To do otherwise may result in a false reading or damage to your meter.

false reading or damage to your meter.

5. Do not touch any part of the circuit on the PCB since static electric discharge may damage this control

5. Do not touch any part of the circuit on the PCB since static electric discharge may damage this control panel.

panel.

Always touch yourself to ground while working on this panel to discharge any static charge built up in your

body. (Micom model only)

CONDITION

Microwave oven

does not work.

Output power is too low. Low AC input voltage.

Sparks occur.

Inserting many plugs into one

Inserting many plugs into one outlet and using them at the

outlet and using them at the

outlet and using them at the same time.

same time.

same time. (blown fuse or breaker)

(blown fuse or breaker)

Microwave oven plug is not

Microwave oven plug is not inserted tightly.

inserted tightly.

Food temperature is too low.

Using metallic ware and

Using metallic ware and allowing it to touch the oven

allowing it to touch the oven

allowing it to touch the oven wall.

wall.

CAUSE REMEDY

Avoid using other electrical

Avoid using other electrical appliances when you use the

appliances when you use the

appliances when you use the microwave oven.

microwave oven.

Insert microwave oven plug

Insert microwave oven plug securely.

securely.

Use the microwave oven at

Use the microwave oven at adequate line voltage.

adequate line voltage.

This may not be a defect.

This may not be a defect. It is possible that the food

It is possible that the food

It is possible that the food should be cooked for a

should be cooked for a

should be cooked for a longer time period.

longer time period.

Do not use metallic ware for

Do not use metallic ware for cooking except that noted in

cooking except that noted in

cooking except that noted in the cooking guide.

the cooking guide.

Uneven cooking.

Ceramic ware trimmed in

Ceramic ware trimmed in gold or silver powder is used.

gold or silver powder is used.

Inconsistent intensity of

Inconsistent intensity of microwave by their

microwave by their

microwave by their characteristics.

characteristics.

Display "CALL SERVICE"

5-11

Do not use any type of

Do not use any type of cookware with metallic

cookware with metallic

cookware with metallic trimming.

trimming.

1. Use plastic wrap or lid.

2. Stir once or twice while

2. Stir once or twice while cooking soup, cocoa or

cooking soup, cocoa or

cooking soup, cocoa or milk, etc.

milk, etc.

This may be cause

This may be cause incomplete connect to H.V.

incomplete connect to H.V.

incomplete connect to H.V. transformer.

transformer.

1. Incomplete segments. ¥ Segment missing. ¥ Partial segment missing. ¥ Digit flickering (NOTE: Slight flickering is normal.)

2. Colon does not turn on or blink.

3. A distinct change in the brightness of one or more numbers in display.

4. One or more digits in the display are not lighting.

5. Display indicates a number different from one touched, for example, key in 5 and 3 appears in the display.

6. Specific numbers (for example 7 or 9) will not display when key pad is touched.

7. Display does not count down with time blinking or up with clock operation.

8. Display obviously jumps in time while counting down.

9. Display counts down too fast while cooking.

10. Each indicator light does not turn on after setting cooking cycle.

11. Display time of day does not reappear when cooking is finished.

5-12

(TROUBLE 1)

The following visual conditions indicate a probable defective control circuit.

CONDITION CHECK RESULT CAUSE REMEDY

1. No input can be programmed.

Continuity

No continuity

Defective PCB assembly.

Loose connection.

Replace PCB assembly.

Connect them tightly.

Check the connection between membrane key assembly and PCB assembly.

2. Some inputs cannot be programmed.

3. Display shows a number or figure different from one touched.

4. Random programming when touching other pads.

5. Display is fixed at some figure and can not accept any input.

Everything works as specified.

Still have trouble.

Defective key membrane assembly.

Defective PCB assembly.

Replace key membrane assembly.

Replace PCB assembly.

Replace key membrane assembly and check operation.

(TROUBLE 2)

Oven does not operate at all, Display window does not display any figures,

Oven does not operate at all, Display window does not display any figures, and no input is accepted.

and no input is accepted.

CONDITION CHECK RESULT CAUSE REMEDY

Replace fuse,

Check continuity

1. Fuse blows. Continuity.

Check continuity of monitor

of monitor

of monitor switch (with

switch (with

switch (with door closed).

door closed).

Replace fuse

Check continuity

Check continuity of primary

of primary

of primary switch (with

switch (with

switch (with door opened).

door opened).

Check continuity

Check continuity of secondary

of secondary

of secondary switch (with

switch (with

switch (with door opened).

door opened).

No continuity.

Continuity.

No continuity.

Continuity.

No continuity.

Malfunction of the

Malfunction of the monitor switch.

monitor switch.

Shorted contact at

Shorted contact at the primary switch.

the primary switch.

Malfunction of

Malfunction of secondary switch.

secondary switch.

Replace fuse,

primary, monitor,

primary, monitor, secondary

secondary

secondary switches, and

switches, and

switches, and RELAY(RY3,5 or

RELAY(RY3,5 or

RELAY(RY3,5 or RY4,6 )

RY4,6 )

RY4,6 ) of P.C.B Assembly.

of P.C.B Assembly.

Replace fuse,

Replace fuse, primary, monitor,

primary, monitor,

primary, monitor, secondary

secondary

secondary switches, and

switches, and

switches, and RELAY(RY3,5 or

RELAY(RY3,5 or

RELAY(RY3,5 or RY4,6 )

RY4,6 )

RY4,6 ) of P.C.B Assembly.

of P.C.B Assembly.

Replace fuse,

Replace fuse, primary, monitor,

primary, monitor,

primary, monitor, secondary

secondary

secondary switches, and

switches, and

switches, and RELAY(RY3,5 or

RELAY(RY3,5 or

RELAY(RY3,5 or RY4,6 )

RY4,6 )

RY4,6 ) of P.C.B Assembly.

of P.C.B Assembly.

Disconnect one

Disconnect one side of the wire

side of the wire

side of the wire lead connected

lead connected

lead connected from transformer

from transformer

from transformer to the high voltage

to the high voltage

to the high voltage capacitor and

capacitor and

capacitor and operate the unit.

operate the unit.

Measure to

Measure to resistance high

resistance high

resistance high voltage capacitor

voltage capacitor

voltage capacitor (refer to page 5-9)

(refer to page 5-9)

Fuse blows again

Normal.

Abnormal.

Defective high volt-

Defective high voltage transformer.

age transformer.

Defective high

Defective high voltage capacitor.

voltage capacitor.

NOTE : All these switches must be replaced at the same time. Refer to page 5-7, 5-8

2. Fuse does not

2. Fuse does not blow.

blow.

Check continuity

Check continuity of thermostat.

of thermostat.

No continuity.

Continuity.

Defective

Defective thermostat.

thermostat.

Replace high volt-

Replace high voltage transformer.

age transformer.

Set is good condition

Set is good condition (defective fuse only)

(defective fuse only)

Replace high

Replace high voltage capacitor.

voltage capacitor.

Replace

Replace thermostat.

thermostat.

Check continuity

Check continuity of power supply

of power supply

of power supply cord.

cord.

No continuity.

5-13

Defective power

Defective power supply cord.

supply cord.

Replace power

Replace power supply cord.

supply cord.

(TROUBLE 3)

CONDITION CHECK RESULT CAUSE REMEDY

Display shows all figures set, but oven does not start cooking while desired

program times are set and START pad is touched.

Defective

Check continuity

1. Setting time

1. Setting time does not count

does not count

does not count down when

down when

down when touching START

touching START

touching START pad.

pad.

2. Blower motor

2. Blower motor or oven lamp

or oven lamp

or oven lamp do not turn on.

do not turn on.

(TROUBLE 4) Oven seems to be operating but little heat is produced in oven load.

Check continuity of secondary

of secondary

of secondary switch (with

switch (with

switch (with door closed).

door closed).

Check the con-

Check the connection between

nection between

nection between CN1 connector

CN1 connector

CN1 connector and PCB

and PCB

and PCB assembly.

assembly.

Check blower motor.

Check oven lamp.

No continuity.

Continuity.

Continuity

No continuity

Abnormal

Abnormal Abnormal

Abnormal

Normal

Defective secondary switch.

secondary switch.

Defective PCB

Defective PCB assembly.

assembly.

Loose connection.

Defective blower motor. Replace blower motor.

Defective blower motor. Replace blower motor. Defective oven lamp. Replace oven lamp.

Defective oven lamp. Replace oven lamp.

Replace

Replace secondary switch.

secondary switch.

Replace PCB

Replace PCB assembly.

assembly.

Connect them

Connect them tightly.

tightly.

CONDITION CHECK RESULT CAUSE REMEDY

Lower than 90% of

Output is low

NOTE :

Simple test of power output-conducted by heating one liter water for one min. if available.

Minimum 8.5°C temperature rise is normal condition.

Check the

Check the power source

power source

power source voltage.

voltage.

Disconnect the

Disconnect the wire leads from

wire leads from

wire leads from relay 3,5 or relay

relay 3,5 or relay

relay 3,5 or relay 4,6 and check

4,6 and check

time

on and off

on and off with multitester.

with multitester.

Measure the

Measure the output power.

output power.

time

Lower than 90% of rating voltage.

rating voltage.

Normal

Abnormal

Normal

Abnormal

Decrease in power

Decrease in power source voltage

source voltage

source voltage with load.

with load.

Defective PCB

Defective PCB assembly.

assembly.

Defective

Defective magnetron.

magnetron.

Suggest customer

Suggest customer contact local

contact local

contact local electric power

electric power

electric power utility co. or

utility co. or

utility co. or qualified

qualified

qualified electrician.

electrician.

electrician. Replace PCB

Replace PCB

Replace PCB assembly.

assembly.

Replace

Replace magnetron.

magnetron.

5-14

5-15

CONDITION CHECK RESULT CAUSE REMEDY

No microwave oscillation.

No continuity.

Continuity.

Abnormal

Defective high voltage transformer.

Replace high voltage transformer.

Normal

Defective PCB assembly.

Replace PCB assembly.

Disconnect the wire leads from relay 2 and check continuity of relay 2. (Operate the unit)

Check high vol- tage transformer

Output is full power when you set lower power level.

Abnormal.

Defective PCB assembly.

Replace PCB assembly.

Disconnect the wire leads from relay 2 and check continuity relay 2. (Operate the unit)

Abnormal

Defective high voltage capacitor.

Replace high voltage capacitor.

Normal

Check high vol- tage capacitor.

Abnormal

Defective high voltage diode.

Replace high voltage diode.

Normal

Check high vol- tage diode.

Abnormal

Defective magnetron.

Replace magnetron.

Check magnetron.

(TROUBLE 5)

No microwave oscillation even though oven lamp and fan motor run. (Display operates properly)

NOTE : ¥ Make sure the wire leads correct position.

¥ When Removing the wire leads from the parts, be sure to grasp the connector, not the wires. ¥ When removing the magnetron, be sure to install the magnetron gasket in the correct position

and in good condition.

CONDITION CHECK RESULT CAUSE REMEDY

No microwave oscillation.

No continuity.

Continuity.

Abnormal

Defective high voltage transformer.

Replace high voltage transformer.

Normal

Defective PCB assembly.

Replace PCB assembly.

Disconnect the wire leads from

4,6 and check

continuity of relay 3,5

or relay 4,6

Check high voltage transformer

Output is full power when you set lower power level.

Abnormal.

Defective PCB assembly.

Replace PCB assembly.

Disconnect the wire leads from relay 3,5 or relay 4,6 and check

continuity relay 3,5 or relay 4,6

(Operate the unit)

Abnormal

Defective high voltage capacitor.

Replace high voltage capacitor.

Normal

Check high voltage capacitor.

Abnormal

Defective high voltage diode.

Replace high voltage diode.

Normal

Check high voltage diode.

Abnormal

Defective magnetron.

Replace magnetron.

Check magnetron.

(TROUBLE 5)

No microwave oscillation even though oven lamp and blower motor run. (Display operates properly)

NOTE : • Make sure the wire leads correct position.

• When Removing the wire leads from the parts, be sure to grasp the connector, not the wires.

• When removing the magnetron, be sure to install the magnetron gasket in the correct position and in good condition.

relay 3,5 or relay

, not the wires., not the wires.

(Operate the unit)

, not the wires.

CONTROL PANEL PARTS

LATCH BOARD PARTS

BASE PLATE PARTS

OVEN CAVITY PARTS

DOOR PARTS

INTERIOR PARTS

#EV#

EXPLODED VIEW

INTRODUCTION

MODEL : RFS18G

6-1

DOOR PARTS

CONTROL PANEL PARTS

LATCH BOARD PARTS

BASE PLATE PARTS

OVEN CAVITY PARTS

INTERIOR PARTS

#EV#

EXPLODED VIEW

INTRODUCTION

MODEL : RFS18MPS

6-2

#EV#

DOOR PARTS

MODEL : RFS18G

RFS18MPS

1013

1005

1004

1385

1002

1000

W136

1006

1007

W105

W108

1009

W206

W207

1384

1386

6-3

2012

2400

2005

2006

2381

2000

W130

W102

#EV#

CONTROL PANEL PARTS

MODEL : RFS18G

6-4

2004

2006

2381

2000

W130

W102

#EV#

CONTROL PANEL PARTS

MODEL : RFS18MPS

6-5

7037

3001

5045

W121

W108

W158

W121

W109

W101

3009

W105

5042

3009

3004

5024

W105

W109

W108

W109

5203

W101

3007

5033

#EV#

OVEN CAVITY PARTS

MODEL : RFS18G

RFS18MPS

6-6

4003

4000

4002

W102

W160

4002

4004

4008

4001

#EV#

LATCH BOARD PARTS

MODEL : RFS18G

RFS18MPS

6-7

W101

5016

5020

3006

5102

3031

5010

W101

W108

W136

5001

5014

5106

5041

5020

5046

5302

W105

5009

W101

W109

W101

W109

5201

5105

5000

W108

W109

5018

W108

5103

3381

3028

5104

5013

5204

W105

9000

#EV#

INTERIOR PARTS

MODEL : RFS18G

RFS18MPS

6-8

5008

6001

6000

W101

W121

W108

6013

W121

3026

3901

3902

W162

5061

#EV#

BASE PLATE PARTS

MODEL : RFS18G

RFS18MPS

6-9

SCHEMATIC DIAGRAM OF P.C.B

7-1

PRINTED CIRCUIT BOARD

7-2

P/No.: 3828W5S3527