Electrolux FMV156DBE User Manual

1

FMV 156 DBE FMV 156DS E FMV 156D QE FMV 156DC F

In the interest of user-safety the oven should be restored to its original condition and only parts identical to those speciﬁed should be used.

WARNING TO SERVICE PERSONNEL: Microwave ovens contain circuitry capable of producing very high voltage and current. Contact with the following parts may result in a severe, possibly fatal, electrical shock. (High Voltage Capacitor, High Voltage Power Transformer, Magnetron, High Voltage Rectiﬁer Assembly, High Voltage Harness etc..)

TABLE OF CONTENTS

Page PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO

AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY..................... INSIDE FRONT COVER

BEFORE SERVICING....................................................................................................... INSIDE FRONT COVER

WARNING TO SERVICE PERSONNEL ................................................................................................................. 3

MICROWAVE MEASUREMENT PROCEDURE..................................................................................................... 4

FOREWORD AND WARNING ............................................................................................................................... 5

PRODUCT SPECIFICATIONS ...............................................................................................................................6

GENERAL INFORMATION.................................................................................................................................... 6

OPERATION........................................................................................................................................................... 9

TROUBLESHOOTING GUIDE............................................................................................................................. 13

TEST PROCEDURE ............................................................................................................................................15

TOUCH CONTROL PANEL ASSEMBLY .............................................................................................................. 25

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE.................................................................29

PICTORIAL DIAGRAM......................................................................................................................................... 37

POWER UNIT CIRCUIT....................................................................................................................................... 38

LSI UNIT CIRCUIT ............................................................................................................................................... 39

PRINTED WIRING BOARD.................................................................................................................................. 40

PARTS LIST ........................................................................................................................................................ 41

PACKING AND ACCESSORIES ..........................................................................................................................45

S95M241FM156E

FMV156DBE FMV156DSE FMV156DQE FMV156DCF

OVER THE RANGE

MICROWAVE OVEN

MODELS

FMV156DCF

ELECTROLUX

SERVICE MANUAL

ElEctrolux HoME ProDuctS, INc.

P. O. Box 212378, Augusta, GA, 30917

800•944•9044

This document has been published to be used for after sales service only. The contents are subject to change without notice.

P/N 316439263Publication # 5995505459

FMV 156DB E FMV15 6D SE FMV 156 DQE FMV15 6D CF

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 genera-

tion 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.

BEFORE SERVICING

Before servicing an operative unit, perform a microwave emission check as per the Microwave Measurement Procedure outlined in this service manual. If microwave emissions level is in excess of the speciﬁed limit, contact ELECTROLUX HOME PRODUCTS, INC. immediately.

If the unit operates with the door open, service person should 1) tell the user not to operate the oven and 2) contact ELECTROLUX HOME PRODUCTS, INC. and Food and Drug Administration's Center for Devices and Radiological Health immediately.

Service personnel should inform ELECTROLUX HOME PRODUCTS, INC. of any certiﬁed unit found with emissions in excess of 4mW/cm2. The owner of the unit should be instructed not to use the unit until the oven has been brought into compliance.

(RD8100U)

2

WARNING TO SERVICE PERSONNEL

Don't Touch ! Danger High Voltage

Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts fatal, electrical shock.

(Example) High Voltage Capacitor, High Voltage Power

Transformer, Magnetron, High Voltage Rectiﬁer Assembly, High Voltage Harness etc..

Read the Service Manual carefully and follow all instructions.

may result in a severe, possibly

FMV 156DB E FMV15 6D SE FMV 156 DQE FMV15 6D CF

Before Servicing

1. Disconnect the power supply cord , an d then remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

WARNING: RISK OF ELECTRIC SHOCK.

DISCHARGE THE HIGH-VOLTAGE CAPACITOR BEFORE SERVICING.

The high-voltage capacitor remains charged about 60 seconds after the oven has been switched off. Wait for 60 seconds and then short-circuit the connection of the high-voltage capacitor (that is the connecting lead of the high-voltage rectiﬁer) against the chassis with the use of an insulated screwdriver.

Whenever troubleshooting is performed the power supply must be disconnected. It may, in some cases, be necessary to connect the power supply after the outer case has been removed, in this event,

1. Disconnect the power supply cord, and then remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect the leads to the primary of the power transformer.

5. Ensure that these leads remain isolated from other components and oven chassis by using insulation tape.

6. After that procedure, reconnect the power supply cord.

When the testing is completed,

1. Disconnect the power supply cord, and then remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Reconnect the leads to the primary of the power transformer.

5. Reinstall the outer case (cabinet).

6. Reconnect the power supply cord after the outer case is installed.

7. Run the oven and check all functions.

After repairing

1. Reconnect all leads removed from components during testing.

2. Reinstall the outer case (cabinet).

3. Reconnect the power supply cord after the outer case is installed.

4. Run the oven and check all functions.

Microwave ovens should not be run empty. To test for the presence of microwave energy within a cavity, place a cup of cold water on the oven turntable, close the door and set the power to HIGH and set the microwave timer for two (2) minutes. When the two minutes has elapsed (timer at zero) carefully check that the water is now hot. If the water remains cold carry out Before Servicing procedure and re-examine the connections to the component being tested.

When all service work is completed and the oven is fully assembled, the microwave power output should be checked and microwave leakage test should be carried out.

3

FMV 156DB E FMV15 6D SE FMV 156 DQE FMV15 6D CF

MICROWAVE MEASUREMENT PROCEDURE

A. Requirements:

1) Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven should not exceed 1mW/cm2 at any point 5cm or more from the external surface of the oven, measured prior to acquisition by a purchaser, and thereafter (through the useful life of the oven), 5 mW/cm2 at any point 5cm or more from the external surface of the oven.

2) Safety interlock switches: Primary interlock switch shall prevent microwave radiation emission in excess of the requirement as above mentioned, secondary interlock relay and door sensing switch shall prevent microwave radiation emission in excess of 5 mW/cm2 at any point 5cm or more from the external surface of the oven.

B. Preparation for testing: Before beginning the actual measurement of leakage, proceed as follows:

1) Make sure that the actual instrument is operating normally as speciﬁed in its instruction booklet.

Important: Survey instruments that comply with the requirement for instrumentation as prescribed by the performance standard for microwave ovens, 21 CFR 1030.10(c)(3)(i), must be used for testing.

2) Place the oven tray in the oven cavity.

3) Place the load of 275±15 ml (9.8 oz) of tap water initially at 20±5½C (68½F) in the center of the oven cavity.

The water container shall be a low form of 600 ml (20 oz) beaker with an inside diameter of approx. 8.5 cm (3-1/2 in.)

and made of an electrically nonconductive material such as glass or plastic.

The placing of this standard load in the oven is important not only to protect the oven, but also to insure that any leakage

is measured accurately.

4) Set the cooking control on Full Power Cooking Mode

5) Close the door and select a cook cycle of several minutes. If the water begins to boil before the survey is completed, replace it with 275 ml of cool water.

C. Leakage test:

Closed-door leakage test (microwave measurement)

1) Grasp the probe of the survey instrument and hold it perpendicular to the gap between the door and the body of the oven.

2) Move the probe slowly, not faster than 1 in./sec. (2.5 cm/sec.) along the gap, watching for the maximum indication on the meter.

3) Check for leakage at the door screen, sheet metal seams and other accessible positions where the continuity of the metal has been breached (eg., around the switches, indicator, and vents).

While testing for leakage around the door pull the door away from the front of the oven as far as is permitted by the

closed latch assembly.

4) Measure carefully at the point of highest leakage and make sure that the highest leakage is no greater than 4mW/cm2, and that the primary interlock switch does turn the oven OFF before any door movement.

4

SERVICE MANUAL

ELECTROLUX

OVER THE RANGE

MICROWAVE OVEN

PRODUCT DESCRIPTION

FMV 156DB E FMV15 6D SE FMV 156 DQE FMV15 6D CF

FMV156DBE / FMV156DSE

FMV156DQE / FMV156DCF

FOREWORD

This Manual has been prepared to provide Electrolux Home Products

Service Personnel with Operation and Service Information for the ELECTROLUX OVER THE RANGE MICROWAVE OVENS, FMV156DBE, FMV156DSE, FMV156DQE, FMV156DCF.

It is recommended that service personnel carefully study the entire text of this manual so that they will be qualiﬁed to render satisfactory customer service.

Check the interlock switches and the door seal carefully. Special attention should be given to avoid electrical shock and microwave radiation hazard.

WARNING

Never operate the oven until the following points are ensured. (A) The door is tightly closed. (B) The door brackets and hinges are not defective. (C) The door packing is not damaged. (D) The door is not deformed or warped. (E) There is not any other visible damage with the oven.

Servicing and repair work must be carried out only by trained service personnel.

DANGER

Certain initial parts are intentionally not grounded and present a risk of electrical shock only during servicing. Service personnel - Do not contact the following parts while the appliance is energized; High Voltage Capacitor, Power Transformer, Magnetron, High Voltage Rectiﬁer Assembly, High Voltage Harness; If provided, Vent Hood, Fan assembly, Cooling Fan Motor.

GENERAL INFORMATION

OPERATION

TROUBLESHOOTING GUIDE AND TEST PROCEDURE

TOUCH CONTROL PANEL

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

WIRING DIAGRAM

PARTS LIST

All the parts marked “ * ” on parts list are used at voltages more than 250V.

Removal of the outer wrap gives access to voltage above 250V.

All the parts marked “ ∆ ” on parts list may cause undue microwave exposure, by themselves, or when they are damaged,

ELECTROLUX HOME PRODUCTS, INC.

5

FMV 156DB E FMV15 6D SE FMV 156 DQE FMV15 6D CF

PRODUCT SPECIFICATION

ITEM DESCRIPTION

Power Requirements 120 Volts / 14.1 Amperes 60 Hertz Single phase, 3 wire grounded

Power Output 950 watts (IEC TEST PROCEDURE) Operating frequency of 2450MHz

Case Dimensions Width 29-15/16" Height 15- 9/16" Depth 16-1/4"

Cooking Cavity Dimensions Width 17-11/16" Height 14-15/16"

1.5 Cubic Feet Depth 9-7/8"

Hood lamp 2 bulbs, 20W x 2, Incandescent light bulbs

Hood fan Approx. 300 C.F.M. (High mode)

Control Complement Touch Control System Clock ( 1:00 - 12:59 ) Timer (0 - 99 min. 99 seconds)

Microwave Power for Variable Cooking

Repetition Rate;

P-HI .................................................. Full power throughout the cooking time

P-90 ..................................................................... approx. 90% of Full Power

P-80 ..................................................................... approx. 80% of Full Power

P-70 ..................................................................... approx. 70% of Full Power

P-60 ..................................................................... approx. 60% of Full Power

P-50 ..................................................................... approx. 50% of Full Power

P-40 ..................................................................... approx. 40% of Full Power

P-30 .................................................................... approx. 30% of Full Power

P-20 ..................................................................... approx. 20% of Full Power

P-10 ..................................................................... approx. 10% of Full Power

P-0 ..................................................... No power throughout the cooking time

Popcorn pad, Reheat pad, Cook pad,

Defrost pad, Number selection pads Power Level pad, Timer / Clock pad Light button, Fan button, Clear/Off button, START/ Plus 1 Min button,

Oven Cavity Light 20W x 1 Incandescent light bulb

Safety Standard UL Listed FCC Authorized

DHHS Rules, CFR, Title 21, Chapter 1, Subchapter J

Weight Approx. 55 lbs.

GENERAL INFORMATION

GROUNDING INSTRUCTIONS

This oven is equipped with a three prong grounding plug. It must be plugged into a wall receptacle that is properly installed and grounded in accordance with the National Electrical Code and local codes and ordinances. In the event of an electrical short circuit, grounding reduces the risk of electric shock by providing an escape wire for the electric current.

WARNING: Improper use of the grounding plug can result in a risk of electric shock.

6

FMV 156DB E

OVEN DIAGRAM

3-Pronged Plug

Grounded Receptacle Box

Grounding Pin

3-Pronged Receptacle

10

11

12

8

7

14

6

9

3

4

5

1

9

13

2

FMV15 6D SE FMV 156 DQE FMV15 6D CF

Electrical Requirements The oven is equipped with a 3-prong grounding plug. DO NOT UNDER ANY CIRCUMSTANCES CUT OR REMOVE THE GROUNDING PIN FROM THE PLUG. The power supply cord and plug must be connected to a separate 120 Volt AC, 60 Hz, 15 Amp. or more dedicated line, using a grounded receptacle. The receptacle should be located inside the cabinet directly above the Microwave Oven/Hood system mounting location.

1. Oven door with see-through window.

2. Door hinges.

3. Waveguide cover.

4. Turntable motor shaft.

5. Oven lamp. It will light when oven is operating or door is

open.

6. Door latches. The oven will not operate unless the door is

securely closed.

7. Auto Touch control panel

8. Time display: Digital display, 99 minutes 99 seconds.

9. Ventilation openings.

10. Light Cover.

11. Grease ﬁlters.

12. Removable turntable. The turntable will rotate clockwise or

counterclockwise.

Only remove for cleaning.

13. Removable turntable support.

14. Power supply cord

7

FMV 156DB E FMV15 6D SE FMV 156 DQE FMV15 6D CF

CONTROL PANEL

NOTE: Some one-touch cooking features such as "Plus 1 Min" are disabled after three minutes when the oven is not used.

These features are automatically enabled when the door is opened and closed or Clear-Off button is pressed.

8

OPERATION

DESCRIPTION OF OPERATING SEQUENCE

FMV 156DB E FMV15 6D SE FMV 156 DQE FMV15 6D CF

The following is a description of component functions during oven operation.

OFF CONDITION

Closing the door activates the door sensing switch and secondary interlock switch. (In this condition, the monitor switch contacts are opened.) When oven is plugged in, 120 volts A.C. is supplied to the control unit. (Figure O-1).

1. The display will show "WELCOME, PRESS CLEAR AND PRESS CLOCK".

To set any program or set the clock, you must ﬁrst touch

the STOP/CLEAR pad. The display will clear, and " : " will appear .

COOKING CONDITION

Program desired cooking time touching the NUMBER pads. When the START pad is touched, the following operations occur:

1. The contacts of relays are closed and components connected to the relays are turned on as follows.

(For details, refer to Figure O-2)

RELAY CONNECTED COMPONENTS

RY1 Oven lamp / Fan motor / Stirrer motor

RY2 Power transformer

RY3 Turntable motor

RY4 Hood fan motor

2. 120 volts A.C. is supplied to the primary winding of the power transformer and is converted to about 3.3 volts A.C. output on the ﬁlament winding, and approximately 2000 volts A.C. on the high voltage winding.

3. The ﬁlament winding voltage heats the magnetron ﬁlament and the H.V. winding voltage is sent to a voltage doubler circuit.

4. The microwave energy produced by the magnetron is channelled through the waveguide into the cavity feedbox, and then into the cavity where the food is placed to be cooked.

5. Upon completion of the cooking time, the power transformer, oven lamp, etc. are turned off, and the generation of microwave energy is stopped. The oven will revert to the OFF condition.

6. When the door is opened during a cook cycle, monitor switch, door sensing switch, primary interlock switch, and secondary interlock relay are activated with the following results. The circuits to the stirrer motor, the cooling fan motor, the turntable motor, and the high voltage components are de-energized, and the digital read-out displays the time still remaining in the cook cycle when the door was opened.

7. The monitor switch is electrically monitoring the

of the primary interlock switch, and door sensing switch

is mechanically associated with the door so that it will function in the following sequence. (1) When the door opens from a closed position, the

secondary interlock relay, door sensing switch, and primary interlock switch open their contacts, and then the monitor switch contacts close.

(2) When the door is closed from the open position,

the monitor switch contacts open ﬁrst. Then the contacts of the primary interlock switch and door sensing switch close. And contacts of

the relay (RY1) open. If the primary interlock switch and secondary interlock relay (RY2) fail with the contacts closed when the door is opened, the closing of the monitor switch contacts will form a short circuit through the monitor fuse, primary interlock switch, relay (RY1) and secondary interlock relay (RY2), causing the monitor fuse to blow.

POWER LEVEL P-0 TO P-90 COOKING

When Variable Cooking Power is programmed, the 120 volts A.C. is supplied to the power transformer intermittently through the contacts of relay (RY2) which is operated by the control unit within an interval second time base. Microwave power operation is as follows:

VARI-MODE ON TIME OFF TIME

Power 10(P-HI) 32 sec. 0 sec.

(100% power)

Power 9(P-90) 30 sec. 2 sec.

(approx. 90% power)

Power 8(P-80) 26 sec. 6 sec.

(approx. 80% power)

Power 7(P-70) 24 sec. 8 sec.

(approx. 70% power)

Power 6(P-60) 22 sec. 10 sec.

(approx. 60% power)

Power 5(P-50) 18 sec. 14 sec.

(approx. 50% power)

Power 4(P-40) 16 sec. 16 sec.

(approx. 40% power)

Power 3(P-30) 12 sec. 20 sec.

(approx. 30% power)

Power 2(P-20) 8 sec. 24 sec.

(approx. 20% power)

Power 1(P-10) 6 sec. 26 sec.

(approx. 10% power)

Power 0(P-0) 0 sec. 32 sec.

(0% power)

Note: The ON/OFF time ratio does not correspond with the

percentage of microwave power, because approx. 2 seconds are needed for heating of the magnetron

9

FMV 156DB E

To Duct

Grease Filter

Hood Intake Duct R

Hood Fan Motor

Grease Filter

To Duct

Hood Intake Duct R

Hood Fan Motor

Hood Intake Duct R

Hood Exhaust Louver

Hood Fan Motor

Charcoal Filter

FMV15 6D SE FMV 156 DQE FMV15 6D CF

VENTILATION METHODS HOT AIR EXHAUST

1. VERTICAL VENTING For this venting method, hot air rising from the conventional

range below is drawn in by the hood fan motor through the grease ﬁlters at the right and left sides of the base cover, up through the right and left sides of the oven cavity, then discharged vertically at rear center top of the oven, into the customer's vent system.

2. HORIZONTAL VENTING The air handing is the same as VERTICAL VENTING

except that the ﬁnal air discharge is directed horizontally out from the top rear of the oven into the customer's vent system.

3. RE-CIRCULATION (INSIDE VENTING) The air handing is the same as VERTICAL VENTING

except that the ﬁnal air discharge is directed horizontally through the upper front of the oven into the kitchen. IN this case, the accessory charcoal ﬁlter RK-240 must be provided to ﬁlter the air before it leaves the oven.

10

FMV 156DB E

NOTES:

1.CIRCUITS SUBJECT TO CHANGE WITHOUT NOTICE.

2. TERMINAL WITH PROJECTION OR OPPOSITE BLUE MARK ON LAMP SOCKET MUST BE CONNECTED TO NEUTRAL WIRE.

3. ONLY CERTAIN MODELS USE THE ABSOLUTE HUMIDITY SENSOR.

4. POWER TRANSFORMER LEFT (FINISH LEAD) TERMINAL MUST BE CONNECTED TO THE NEUTRAL (WHITE) WIRE.

MAG. TEMP. FUSE

CAVITY

THERMAL

CUTOUT

120VAC

60Hz

HOOD FAN THERMAL

CUT OUT

RED

PPL

COM.

RED

WHT

BLK

WHT

GRY

BRN

WHT

RED

WHT

YLW

BLK

WHT

ORG

GRN

A5

A7

A1

A3

A9

N.O.

E2

E1

RY6

HOOD MOTOR

CONTROL UNIT

N.O.

(RY1)

(RY2)

COM.

DOOR SENSING SWITCH

TTM

FMOL

HL

TURN TABLE MOTOR

FAN MOTOR

OVEN LAMP

HOOD LAMP

GRY

MONITOR

SWITCH

PRIMARY INTERLOCK SWITCH

RED

BLU

POWER

TRANSFORMER

MAGNETRON

HIGH VOLTAGE CAPACITOR xx uF

HOOD CAPACITOR

RED

BRN

WHT

SECONDARY

INTERLOCK

RELAY

OVEN LAMP RELAY

ORG

RED

COM

RED

ORG

WHT

RY5

GRY

BLK

WHT

GRY

GND

BRN

WHT

F1

F2

F3

SENSOR

BRN

H

RED

ORG

RED

HIGH VOLTAGE RECTIFIER

WHT

N.C.

WHT

BLU

WHT

HUMIDITY

C3

COM.

N.O.

PPL

WHT

RED

BLU

NOISE SUPRESSION COIL

RESISTOR 470 kW 1/2W

LINE CROSS CAPACITOR 1.0 uF 275V

LINE BYPASS CAPACITOR

0.0033 uF 250V

FUSE

20A

LINE BYPASS CAPACITOR

0.0033 uF 250V

NOISE FILTER

N

L

GND

NOTES:

1.CIRCUITS SUBJECT TO CHANGE WITHOUT NOTICE.

2. TERMINAL WITH PROJECTION OR OPPOSITE BLUE MARK ON LAMP SOCKET MUST BE CONNECTED TO NEUTRAL WIRE.

3. ONLY CERTAIN MODELS USE THE ABSOLUTE HUMIDITY SENSOR.

4. POWER TRANSFORMER LEFT (FINISH LEAD) TERMINAL MUST BE CONNECTED TO THE NEUTRAL (WHITE) WIRE.

MAG. TEMP. FUSE

CAVITY

THERMAL

CUTOUT

120VAC

60Hz

HOOD FAN THERMAL

CUT OUT

RED

PPL

COM.

RED

WHT

BLK

WHT

GRY

BRN

WHT

RED

WHT

YLW

BLK

WHT

ORG

GRN

A5

A7

A1

A3

A9

N.O.

E2

E1

RY6

HOOD MOTOR

CONTROL UNIT

N.O.

(RY1)

(RY2)

COM.

DOOR SENSING SWITCH

TTM

FMOL

HL

TURN TABLE MOTOR

FAN MOTOR

OVEN LAMP

HOOD LAMP

GRY

MONITOR

SWITCH

PRIMARY INTERLOCK SWITCH

RED

BLU

POWER

TRANSFORMER

MAGNETRON

HIGH VOLTAGE CAPACITOR xx uF

HOOD CAPACITOR

RED

BRN

WHT

SECONDARY

INTERLOCK

RELAY

OVEN LAMP RELAY

ORG

RED

COM

RED

ORG

WHT

RY5

GRY

BLK

WHT

GRY

GND

BRN

WHT

F1

F2

F3

SENSOR

BRN

H

RED

ORG

RED

HIGH VOLTAGE RECTIFIER

WHT

N.C.

WHT

BLU

WHT

HUMIDITY

C3

COM.

N.O.

PPL

WHT

RED

BLU

NOISE SUPRESSION COIL

RESISTOR 470 kW 1/2W

LINE CROSS CAPACITOR 1.0 uF 275V

LINE BYPASS CAPACITOR

0.0033 uF 250V

FUSE

20A

LINE BYPASS CAPACITOR

0.0033 uF 250V

NOISE FILTER

N

L

GND

FMV15 6D SE FMV 156 DQE FMV15 6D CF

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. CLOCK APPEARS ON DISPLAY.

Figure O-1. Oven Schematic-Off Condition

Figure O-2. Oven Schematic-Cooking Condition

11

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. COOKING TIME PROGRAMMED.

3. VARIA B L E C O O K I N G C O N TRO L "HIGH".

FMV 156DB E

Latch hook

Door sensing switch

Latch heads

Monitor switch

Primary interlock switch

Door

FMV15 6D SE FMV 156 DQE FMV15 6D CF

DESCRIPTION AND FUNCTION OF COMPONENTS

DOOR OPEN MECHANISM

The door is opened by pulling the door handle, refer to the Figure D-1.

Figure D-1. Door Open Mechanism

DOOR SENSING SWITCH, PRIMARY INTERLOCK SWITCH

The primary interlock switch is mounted in the lower position of the latch hook, the door sensing switch in the primary interlock system is mounted in the upper position of the latch hook is mounted on upper position of the latch hook. They are activated by the latch heads on the door. When the door is opened, the switches interrupt the circuit to all components. A cook cycle cannot take place until the door is ﬁrmly closed thereby activating both interlock switches. The primary interlock system consists of the door sensing switch and secondary interlock relay located on the control circuit board.

MONITOR SWITCH

The monitor switch is activated (the contacts opened) by the latch head on the door while the door is closed. The switch is intended to render the oven inoperative, by means of blowing the monitor fuse, when the contacts of the secondary interlock relay (RY2) and primary interlock switch fail to open when the door is opened.

Functions:

1. When the door is opened, the monitor switch contact close (to the ON condition) due to their being normally closed. At this time the secondary interlock relay (RY2), primary interlock switch are in the OFF condition (contacts open) due to their being normally open contact switches. And the contacts of relay (RY1) are in the ON condition (contacts close).

2. As the door goes to a closed position, the monitor switch contacts are ﬁrst opened and then the door sensing switch and the primary interlock switch contacts close. (On opening the door, each of these switches operate inversely.)

3. If the door is opened, and the secondary interlock relay (RY2) and primary interlock switch contacts fail to open, the monitor fuse blows simultaneously with closing of the

CAUTION: BEFORE REPLACING A BLOWN MONITOR

FUSE TEST THE DOOR SENSING SWITCH, SECONDARY INTERLOCK RELAY (RY2), RELAY (RY1), PRIMARY INTERLOCK SWITCH AND MONITOR SWITCH FOR PROPER OPERATION. (REFER TO CHAPTER "TEST PROCEDURE").

NOTE: MONITOR FUSE AND MONITOR SWITCH ARE

REPLACED AS AN ASSEMBLY.

THERMAL CUT-OUT (HOOD )

This thermal cut-out located on the right base plate. It is designed to automatically turn on the hood fan motor whenever the hot air rising from the conventional range below causes the temperature at the thermal cut-out to rise to 140OF (60OC) or higher, thus removing this hot air from around microwave oven. When the temperature around the thermal cut-out drops to 113OF (45OC) or lower, the thermal cut-out shuts off the hood fan motor.

THERMAL CUT-OUT (CAVITY )

This thermal cut-out is located on the top of the oven cavity. It is designed to prevent damage to the oven unit if the food in the oven catches ﬁre due to overheating produced by improper setting of cooking time or failure of control unit. Under normal operation, the thermal cut-out remains closed. However, the thermal cut-out will open at 293OF (145OC) causing the oven to shut down.

TURNTABLE MOTOR

The turntable motor rotates the turntable located on the bottom of the oven cavity, so that the foods on the turntable cook evenly during cooking. Turntable will turn in either direction. The turntable motor can be turned off by touching TURNTABLE ON/OFF pad.

COOLING FAN MOTOR

The cooling fan motor drives a blade which draws external cool air. This cool air is directed through the air vanes surrounding the magnetron and cools the magnetron. This air is channelled through the oven cavity to remove steam and

vapors given off from the heating foods. It is then exhausted through the exhausting air vents at the oven cavity.

HOOD FAN MOTOR

The hood fan motor is a one-speed, single-phase, double pole induction type, requiring a hood fan capacitor. It is located outside the upper rear part of the oven cavity, is to remove, from around the oven, hot air rising from the conventional electric or gas range over which it is installed. This air is then expelled either vertically or horizontally

through the customer supplied duct system, or discharged back into the kitchen.

HOOD LAMP

The hood lamps are mounted at the hood lamp angle on the base cover. The hood lamps can be turned off and on

12

FMV 156DB E FMV15 6D SE FMV 156 DQE FMV15 6D CF

TROUBLESHOOTING GUIDE

Never touch any part in the circuit with your hand or an uninsulated tool while the power supply is connected.

When troubleshooting the microwave oven, it is helpful to follow the Sequence of Operation in performing the checks. Many of the possible causes of trouble will require that a speciﬁc test be performed. These tests are given a procedure letter which will be found in the "Test Procedure "section.

IMPORTANT: If the oven becomes inoperative because of a blown monitor fuse, check the monitor switch, relay (RY1)

secondary interlock relay (RY2), door sensing switch and primary interlock switch before replacing the monitor fuse. If the monitor fuse is replaced, the monitor switch must also be replaced. Use part FFS-BA016/KIT as an assembly.

IMPORTANT: Whenever troubleshooting is performed with the power supply cord disconnected. It may in, some cases,

be necessary to connect the power supply cord after the outer case has been removed, in this event,

1. Disconnect the power supply cord, and then remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect the leads to the primary of the power transformer.

5. Ensure that the leads remain isolated from other components and oven chassis by using insulation tape.

6. After that procedure, reconnect the power supply cord.

When the testing is completed

1. Disconnect the power supply cord, and then remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Reconnect the leads to the primary of the power transformer.

5. Reinstall the outer case (cabinet).

6. Reconnect the power supply cord after the outer case is installed.

13

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FMV 156DB E FMV15 6D SE FMV 156 DQE FMV15 6D CF

CK = Check / RE = Replace

14

TEST PROCEDURES

PROCEDURE LETTER A MAGNETRON ASSEMBLY TEST

1. Disconnect the power supply cord, and then remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. To test for an open ﬁlament, isolate the magnetron from the high voltage circuit. A continuity check across the magnetron ﬁlament leads should indicate less than 1 ohm.

5. To test for a shorted magnetron, connect the ohmmeter leads between the magnetron ﬁlament leads and chassis ground. This test should indicate an inﬁnite resistance. If there is little or no resistance the magnetron is grounded and must be replaced.

6. Reconnect all leads removed from components during testing.

7. Reinstall the outer case (cabinet).

8. Reconnect the power supply cord after the outer case is installed.

9. Run the oven and check all functions.

MICROWAVE OUTPUT POWER

The following test procedure should be carried out with the microwave oven in a fully assembled condition (outer case ﬁtted).

HIGH VOLTAGES ARE PRESENT DURING THE COOK CYCLE, SO EXTREME CAUTION SHOULD BE OBSERVED.

Power output of the magnetron can be measured by performing a water temperature rise test. This test should only be used if above tests do not indicate a faulty magnetron and there is no defect in the following components or wiring: silicon rectiﬁer, high voltage capacitor and power transformer. This test will require a 16 ounce (453cc) measuring cup and an accurate mercury thermometer or thermocouple type temperature tester. For accurate results, the following procedure must be followed carefully:

1. Fill the measuring cup with 16 oz. (453cc) of tap water and measure the temperature of the water with a thermometer or thermocouple temperature tester. Stir the thermometer or thermocouple through the water until the temperature stabilizes. Record the temperature of the water.

2. Place the cup of water in the oven. Operate oven at POWER 10(HIGH) selecting more than 60 seconds cook time. Allow the water to heat for 60 seconds, measuring with a stop watch, second hand of a watch or the digital read-out countdown.

3. Remove the cup from the oven and again measure the temperature, making sure to stir the thermometer or thermocouple through the water until the maximum temperature is recorded.

4. Subtract the cold water temperature from the hot water temperature. The normal result should be

29.2 to 54.2οF(16.2 to 30.1οC) rise in temperature. If the water temperatures are accurately measured and tested for the required time period the test results will indicate if the magnetron tube has low power output (low rise in water temperature) which would extend cooking time or high power output (high rise in water temperature) which would reduce cooking time. Because cooking time can be adjusted to compensate for power output, the magnetron tube assembly should be replaced only if the water temperature rise test indicates a power output well beyond the normal limits. The test is only accurate if the power supply line voltage is 120 volts and the oven cavity is clean.

COMPONENT TEST

FMV 156DB E FMV15 6D SE FMV 156 DQE FMV15 6D CF

B POWER TRANSFORMER TEST

1. Disconnect the power supply cord, and then remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect the primary input terminals and measure the resistance of the transformer with an ohmmeter. Check for continuity of the coils with an ohmmeter. On the R x 1 scale, the resistance of the primary coil should be less than 1 ohm and the resistance of the high voltage coil should be approximately 83 ohms; the resistance of the ﬁlament coil should be less than 1 ohm.

5. Reconnect all leads removed from components during testing.

6. Reinstall the outer case (cabinet).

7. Reconnect the power supply cord after the outer case is installed.

8. Run the oven and check all functions.

15