1997 E
SERVICE MANUAL
for the
OVER-THE-RANGE
MICROWAVE OVEN HOOD
COMBINATION
1997 “E” Models
March, 1997
Printed in U.S.A. LIT4322167
THIS MANUAL CONTAINS INFORMATION NECESSARY FOR SERVICING THE WHIRLPOOL MICROWAVE OVEN HOOD COMBINATION , MODELS:
MH7130XE
MH7135XE
MH9115XE
THE MANUAL IS DESIGNED TO BE USED ONLY BY
QUALIFIED SERVICE PERSONNEL. THE SERVICE
INFORMATION IS ORGANIZED TO HELP YOU EASILY FIND WHAT YOU NEED.
CHECK YOUR LOCAL BUILDING CODE FOR THE
PROPER MODE OF INSTALLATION. IN THE ABSENCE OF LOCAL CODES, THIS UNIT SHOULD BE
INSTALLED IN ACCORDANCE WITH THE
NATIONAL
ELECTRICAL CODE, ANSI/NFPA NO. 70 - 1990, OR
LATEST EDITION, OR C22.1 CANADIAN ELECTRICAL CODE, PART 1
.
This Microwave Service Manual is for authorized WHIRLPOOLSM service technicians only.
Because of the high voltage and the critical nature of the door closure system for the microwave
oven, Whirlpool recommends that customers DO NOT service their own microwave oven.
If you encounter problems with any Whirlpool range having a microwave feature, call your nearest
authorized WHIRLPOOLSM Service Company for service.
ii
Cooking Products Service Manual
Original March, 1997 4322167
© 1997 Whirlpool Corporation
Page iii
TABLE OF CONTENTS
Page
Important Safety Information ...............................................................................................................................v
Theory Of Operation ......................................................................................................................................... 1-1
Component Access ........................................................................................................................................... 2-1
Component Sections .................................................................................................................................. 2-1
General ...............................................................................................................................................................
Removing The Microwave Oven & Cabinet ............................................................................................ 2-2
The Protection Control System .......................................................................................................................
Removing The Oven Door ......................................................................................................................... 2-4
Removing The Oven Door Components.................................................................................................. 2-5
Removing The Control Panel .................................................................................................................... 2-6
Removing The Line Fuse........................................................................................................................... 2-7
Removing/Adjusting The Interlock Switches .......................................................................................... 2-8
Removing The Base Thermal Fuse........................................................................................................ 2-10
Removing The Magnetron Thermal Fuse .............................................................................................. 2-11
Removing The Convection Thermistor .................................................................................................. 2-12
Removing The Cavity Thermal Fuse ..................................................................................................... 2-14
The Operating Control System......................................................................................................................
Removing The Oven Light Socket.......................................................................................................... 2-15
Removing The Control Circuit Board & The Turntable Indicator Circuit Board ..............................2-16
Removing The Fan Motor ........................................................................................................................ 2-17
Removing The Power Cord .....................................................................................................................2-18
Removing The Blower Motor Capacitor................................................................................................. 2-19
Removing The Convection Heating Element ........................................................................................ 2-20
Removing The Gas Sensor .....................................................................................................................2-22
Removing The Stirrer Motor .................................................................................................................... 2-23
Removing The Turntable Motor .............................................................................................................. 2-24
Removing The Cooktop Light Sockets ..................................................................................................2-25
The High Voltage Components .....................................................................................................................
Accessing The Components.................................................................................................................... 2-26
Removing The Magnetron .......................................................................................................................2-27
Removing The High Voltage Rectifier And The High Voltage Capacitor ......................................... 2-28
Removing The High Voltage Transformer............................................................................................. 2-29
2-2
2-4
2-15
2-26
iii
Page
Component Description & Testing .................................................................................................................. 3-1
Important Safety Instructions .................................................................................................................... 3-1
The Thermal Fuses..................................................................................................................................... 3-4
The Blower Motor Capacitor ..................................................................................................................... 3-5
The Gas Sensor .......................................................................................................................................... 3-6
The Convection Thermistor ....................................................................................................................... 3-7
The Convection Heating Element............................................................................................................. 3-8
Motors ........................................................................................................................................................... 3-9
Programming Checks ............................................................................................................................... 3-10
Charts ......................................................................................................................................................... 3-11
Checking The Microwave Power Output ............................................................................................... 3-14
Checking For Microwave Energy Leakage ...........................................................................................3-15
Component Testing ..................................................................................................................................3-18
Control Circuit Board Checklist ..............................................................................................................3-23
Primary, Monitor, & Secondary Switch Checkout Procedure............................................................. 3-24
Tech Tips ............................................................................................................................................................ 4-1
Wiring Diagrams.......................................................................................................................................... 4-1
Strip Circuits ................................................................................................................................................ 4-3
Specifications .............................................................................................................................................. 4-6
Model & Serial Number Explanation ...................................................................................................... 4-15
Whirlpool Microwave Hood Warranty..................................................................................................... 4-16
iv
IMPORTANT SAFETY INFORMATION
WARNING
This service manual is intended for factoryservice technicians only. We recommend that
customers DO NOT service their own units,
because of the complexity and risk of highvoltage electrical shock.
The following information is used throughout
this manual, and should be read carefully.
NOTE
Cooking Products Service Manual
Original March, 1997 4322167
© 1997 Whirlpool Corporation
Fire Hazard
Do not obstruct the flow of ventilation air.
Electrical Shock Hazard
It is the customer’s responsibility to:
• Contact a qualified electrical installer.
Page v
Helpful information that explains a more
complicated step, prior to carrying it out.
CAUTION
Information that will help you avoid actions
that could cause product damage (scratches,
dents, etc.) and damage to personal property.
WARNING
Information that alerts you to potentially
dangerous conditions. These conditions can
cause serious personal injury (burns, fire
and electrical shock, etc.) if the suggested
procedures are not observed.
• Assure that electrical installation is adequate and in conformance with the National Electrical Code, ANSl/NFPA 70—
latest edition*, and all local codes and
ordinances.
Failure to do so could result in fire, electrical
shock, or other personal injury.
Take special care when drilling holes into
the wall for venting or electrical wiring. Electrical wires may be concealed behind the
wall covering.
Failure to do so could result In fire, electrical shock, or other personal injury.
• National Fire Protection Association
Batterymarch Park
Quincy, Massachusetts 02269
WHIRLPOOL ASSUMES NO RESPONSIBILITY
FOR ANY REPAIRS MADE ON OUR PRODUCTS
BY ANYONE OTHER THAN AUTHORIZED
WHIRLPOOL SERVICE TECHNICIANS.
v
CAUTION
WARNING TO SERVICE TECHNICIANS
To avoid possible exposure to microwave radiation or energy, visually check the oven for
damage to the door and door seal before
operating the oven. Use your microwave survey meter to check the amount of leakage
before servicing. In the event that the R.F.
Ieakage exceeds 4 mw/cm
ate repair must be made before continuing to
service the unit. Check interlock function by
operating the door latch. The oven cook cycle
should cut off before the door can be opened.
The door and latching assembly contains the
radio frequency energy within the oven. The
door is protected by three safety interlock
switches. Do not attempt to defeat them. Under no circumstances should you try to operate the oven with the door open.
2
at 5 cm, appropri-
• Proper operation of the microwave ovens
requires that the magnetron be properly
assembled to the waveguide and cavity.
Never operate the magnetron unless it is
properly installed.
• Be sure the “RF” seal is not damaged, and
assembled around the magnetron dome
properly when installing the magnetron.
• Routine service safety procedures should
be exercised at all times.
• Untrained personnel should not attempt
service without a thorough review of the test
procedures and safety information contained
in this manual.
PRECAUTIONS TO BE OBSERVED BEFORE AND DUR-
ING SERVICING TO AVOID POSSIBLE EXPOSURE TO
EXCESSIVE MICROWAVE ENERGY.
1. Do not operate or allow the oven to be
operated with the door open.
2. Make the following safety checks on all
ovens to be serviced before activating the
magnetron or other microwave source,
and make repairs as necessary:
a)Interlock Operation.
b)Proper Door Closing.
c) Seal and Sealing Surfaces (Arcing,
Wear, and Other Damage).
d)Damage to or Loosening of Hinges and
Latches.
e)Evidence of Dropping or Abuse.
3. 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.
4. 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.
5. A microwave leakage check to verify compliance with the Federal performance
standard should be performed on each
oven prior to release to the owner.
6. Do not attempt to operate the oven if the
door glass is broken.
vi
CAUTION
WARNING
Whirlpool microwave ovens have a monitoring
system designed to assure proper operation
of the safety interlock systems.
Cooking Products Service Manual
Original March, 1997 4322167
© 1997 Whirlpool Corporation
Page vii
The interlock monitor switch will immediately
cause the oven fuse to blow if the door is
opened while the following combined failure
exists:
Primary door interlock switch and/or secondary interlock switch contacts failed in a closed
position.
CAUTION: REPLACE BLOWN
FUSE WITH 15 AMPERE CLASS H
FUSE ONLY.
Before replacing the blown oven fuse, test the
upper and lower door interlock switches, cook
relay or latch relay, and interlock monitor switch
(middle switch) for proper operation as described in the component test procedures.
DO NOT ATTEMPT TO REPAIR STICKING
CONTACTS OF ANY INTERLOCK SWITCH,
SAFETY SWITCH, OR COOK (LATCH) RELAY (REPLACE SWITCHES).
Any indication of sticking contacts during component test requires replacement of that component to assure reliability of the safety interlock system.
IF THE FUSE IS BLOWN, THE MONITOR,
PRIMARY INTERLOCK AND SECONDARY
INTERLOCK SWITCHES MUST ALSO BE
REPLACED. BE SURE THEY ARE PROPERLY CONNECTED.
NOTES:
• For proper repair and assembly of the oven
door, refer to pages 2-4 and 2-5.
• Interlock switches are not adjustable individually.
• For proper repair and adjustment of the
interlock switches, refer to page 2-8.
DISCONNECT FROM POWER SUPPLY
BEFORE SERVICING.
CAUTION: HIGH VOLTAGES ARE
PRESENT DURING THE COOK
CYCLE. EXTREME CAUTION
SHOULD BE OBSERVED AT ALL
TIMES.
CAUTION: DO NOT TOUCH
OVEN COMPONENTS OR WIRING DURING OVEN OPERATION.
ATTACH METER LEADS WITH
ALLIGATOR CLIPS WHEN MAKING OPERATIONAL TESTS.
CAUTION: IT IS NEITHER NECESSARY NOR ADVISABLE TO
ATTEMPT MEASUREMENT OF
HIGH VOLTAGES.
CAUTION: BEFORE TOUCHING
ANY OVEN COMPONENTS OR
WIRING, ALWAYS UNPLUG THE
OVEN FROM ITS POWER
SOURCE AND DISCHARGE THE
CAPACITOR BY USING A
20,000-OHM DISCHARGE RESISTOR.
USE AN INSULATED PLASTICHANDLE SCREWDRIVER AND
SHORT ACROSS THE CAPACITOR TERMINALS.
OR
vii
R.F. LEAKAGE TEST
CAUTION
EQUIPMENT
• Electromagnetic energy leakage monitor
(NARDA 8100B, HOLADAY H1501).
• 600 ml glass beaker.
• Glass thermometer 100°C or 212° F.
TEST
On every service call, checks for microwave
energy emission must be made according to
the following manner.
1. Remove the cooking rack from the oven
cavity, if the microwave oven is so
equipped.
2. Place a 250 ML (8.0 oz.) glass of water in
the center of the oven bottom.
3. Select “HIGH” cook power, turn the mi-
crowave oven on, and test for R.F. Ieakage
at the following locations using the pattern shown below:
a) Around the cabinet at the front.
b) Around the door.
c) Across the console panel.
d) Horizontally across the door.
e) Vertically across the door.
f) Diagonally across the door.
g) Across the air vents.
h) Across the rear air vent.
i) All lockseams.
j) Weld at bottom.
k) Bottom plate.
I) Oven feet.
4. The scan speed is one inch per second.
When checking for R.F. Ieakage, use an approved R.F. measuring device to assure less
than 4 mw/cm
a maximum scan rate of 2.5 cm/second, in
compliance with U.S. Government Department
of Health, Education and Welfare 21 CFR1030,
performance Standard for Microwave Ovens.
A properly operating door and seal assembly
will normally register small emissions, but they
must be no greater than 4 mw/cm
measurement uncertainty.
NOTE: Enter leakage readings in space BEFORE and AFTER on the service document.
All microwave ovens exceeding the emission
level of 4 mw/cm
Service for microwave ovens immediately and
the owner should be told not to use the microwave oven until it has been repaired completely.
If a microwave oven is found to operate with
the door open, report to Dept. of Service, the
manufacturer and CDRH* immediately. Also
tell the owner not to use the oven.
* CDRH: Center for Device and Radiological Health, Food
and Drug Administration.
The interlock monitor switch acts as the final
safety switch protecting the customer from
microwave radiation. If the interlock monitor
switch operated to blow the fuse when the
interlocks failed you must replace all interlock
switches—primary and secondary interlock
switches and the monitor switch with new
ones because the contacts of those interlock
switches may be melted and welded together.
All repairs must be performed in such a manner that microwave energy emissions are minimal.
Address for CDRH is:
Office of Compliance (HFZ-312) Center for
Devices and Radiological Health
1390 Piccard Drive
Rockville, Maryland 20850
2
emission at 5 cm distance with
2
to allow for
2
must be reported to Dept. of
viii
THEORY OF OPERATION
Cooking Products Service Manual
Original March 1997 4322167
© 1997 Whirlpool Corporation
Page 1-1
The microwave oven is powered by the 120volt line. Whenever the door is closed and a
cooking function is programmed through the
control panel’s keypad, relay contacts on the
control board close, and complete a circuit
from the L1 side to the neutral side of the line.
The control board uses five relays to operate
the various functions of the microwave oven
Relay 4 controls the speed of the blower motor
through the contol panel. The base thermal
fuse will also turn the blower motor on to its
low speed if the temperature reaches 133˚F.
The schematic configuration for relay 4 is
shown in the following diagram. The relay is
explained in further detail on the following
page.
L1
(see below). The relays are controlled by the
microcomputer on the control board, and per-
(NC)
(C)
(NO)
form the functions shown below.
RELAY 4
Relay 1 ........................................................ Oven Light/Fan & Stirrer Motors
Relay 2 ........................................................ High Voltage Section
Relay 3 ........................................................ Low-Speed Blower Motor
Relay 4 (N.C. Contacts) ........................... Auto Low-Speed Blower Motor
Relay 4 (N.O. Contacts) ........................... High-Speed Blower Motor
Relay 5 ........................................................ Turntable Motor
BASE
THERMAL
FUSE
BLOWER
MOTOR
(LOW)
(HI)
(C)
CN3
CONTROL
CIRCUIT
BOARD
RELAY RY1
RELAY RY5
MICROCOMPUTER
RELAY RY2
RELAY RY4
RELAY RY3
1-1
The normally-closed (N.C.) contacts of relay 4 provide a potential circuit for the Base Thermal
Fuse. If the base of the oven exceeds 133˚F, the thermal fuse contacts close, and a circuit for
the low-speed side of the blower motor is completed, which turns the motor on. The low-speed
blower will operate until the base temperature drops below 104˚F and opens the thermal fuse
contacts, and turns off.
L1
BK
20A LINE
FUSE
BK
MAGNETRON
THERMAL
FUSE
BK
CAVITY
THERMAL
FUSE
MICROCOMPUTER
RD
TRANSFORMER
3 1
BOARD
LOW-VOLTAGE
RELAY 4
11
YL
THERMAL
BASE
FUSE
W
CAPACITOR
RD RD
W
BLOWER
MOTOR
N
BL
(C)(HIGH)
When the low-speed fan is selected by the user at the control panel, relay 3 and the normallyclosed (N.C.) contacts of relay 4, complete the circuit to the low-speed windings of the blower
motor and turn it on.
L1
20A LINE
FUSE
RDBK
MAGNETRON
THERMAL
FUSE
BK
CAVITY
THERMAL
USE
MICROCOMPUTER
LOW-VOLTAGE
RD
TRANSFORMER
3 1
BOARD
RELAY 4
RELAY 3
W
CAPACITOR
9
PK/W
(LOW)
BLOWER MOTOR
RDRD
(C)
N
BL
When the high-speed fan is selected by the user at the control panel, the normally-open (N.O.)
contacts of relay 4 complete the circuit to the high-speed windings of the blower motor and turn
it on.
L1
BK
20A LINE
FUSE
RD
MAGNETRON
THERMAL
FUSE
BK
CAVITY
THERMAL
FUSE
MICROCOMPUTER
RD
TRANSFORMER
3 1
BOARD
LOW-VOLTAGE
RELAY 4
13
W
CAPACITOR
RDRD
BK
(HI) (C)
BLOWER MOTOR
N
BL
1-2
COMPONENT ACCESS
COMPONENT SECTIONS
This section instructs you on how to service
the individual components in the Microwave
Oven Hood Combination. These components
(shown below) and their sections are as follows:
• General
Cabinet
• The Protection Control System
Oven Door
Oven Door Components
Control Panel
Line Fuse
Interlock Switches
Base Thermal Fuse
Magnetron Thermal Fuse
Convection Thermistor
Cavity Thermal Fuse
Cooking Products Service Manual
Original March, 1997 4322167
© 1997 Whirlpool Corporation
Page 2-1
• The Operating Control System
Oven Light Socket
Control Circuit Board
Turntable Indicator Circuit Board
Fan Motor
Power Cord
Blower Motor Capacitor
Convection Heating Element
Gas Sensor
Stirrer Motor
Turntable Motor
Cooktop Light Socket
• The High Voltage Components
Magnetron
Rectifier
Capacitor
Transformer
Refer to the section on the following pages for
the component you wish to service.
GAS SENSOR (NOT ON ALL MODELS)
BLOWER MOTOR CAPACITOR
CAVITY THERMAL FUSE
CONVECTION HEATING ELEMENT
(NOT ON ALL MODELS)
BLOWER MOTOR
CONVECTION THERMISTOR
(NOT ON ALL MODELS)
TURNTABLE MOTOR
COOKTOP LIGHTS
SECONDARY INTERLOCK SWITCH
INTERLOCK MONITOR SWITCH
PRIMARY INTERLOCK SWITCH
CONTROL CIRCUIT BOARD
TURNTABLE INDICATOR CIRCUIT BOARD
LINE FUSE
STIRRER MOTOR
OVEN LIGHT
MAGNETRON
THERMAL FUSE
FAN MOTOR
MAGNETRON
HV CAPACITOR
HV RECTIFIER
HV TRANSFORMER
BASE THERMAL FUSE
Base Thermal Fuse ................................................. Closes @ 133˚F/56˚C, resets @ 104˚F/40˚C.
Magnetron Thermal Fuse ...................................... Opens @ 228˚F/109˚C, resets @ 140˚F/60˚C.
Cavity Thermal Fuse .............................................. Opens @ 230˚F/110˚C, resets @ 140˚F/60˚C.
2-1
GENERAL
REMOVING THE MICROWAVE OVEN & CABINET
WARNING
Personal Injury Hazard
Disconnect from the electrical supply before servicing the unit. Failure to do so
could result in death or electrical shock.
IMPORTANT NOTE: Most of the microwave
components can be serviced without removing the unit or its cabinet. They can be accessed by removing the vent grille and the
control panel. Before removing the unit or its
cabinet, first check the procedure for the component you wish to service to see if it is necessary. If it is necessary to remove the unit and
its cabinet to service a component, use the
following procedure.
4. Support the front of the microwave oven
and remove the two bolts and washers
from the top of the oven.
5. Using two people, remove the microwave
oven from its mounting location and set it
on a protected (padded) work surface.
CAUTION: Because of the weight and size of
the microwave oven, two people are required
to safely move and install it. Failure to do so
could result in personal injury.
1. Disconnect the electrical supply to the
microwave oven.
2. Remove the six screws from the base
plate and lower it, (see the illustration on
the next page), then disconnect the
cooktop light connector, and set the base
plate aside.
3. Remove the lock pin and washer from the
top of the microwave oven.
LOCK PIN &
WASHER
6. To remove the vent grille from the microwave oven, remove the two inside screws
from the top of the cabinet, then pull the
top of the vent grille out so the two center
tabs are free of their slots, and remove
the grille.
7. Remove the screw from the power cord
cover and remove the cover.
8. Remove the remaining screws from the
top and rear of the cabinet.
9. Slide the cabinet back and unhook the
sides from the tabs, then slide the power
cord out of the cabinet, and remove the
cabinet.
Proceed to the section for the component you
wish to service.
2-2
VENT
GRILLE
CABINET
SCREW
VENT
GRILLE
SCREWS (2)
TAB SLOTS
Cooking Products Service Manual
Original March, 1997 4322167
© 1997 Whirlpool Corporation
CABINET
Page 2-3
POWER
CORD
POWER
CORD COVER
CABINET
SCREWS
BASE
PLATE
CONNECTORS
SLOTS
BASE PLATE
SCREWS
(6)
COOKTOP LIGHT
ASSEMBLY WIRING
Removing The Cabinet
2-3
THE PROTECTION CONTROL SYSTEM
REMOVING THE OVEN DOOR
WARNING
Personal Injury Hazard
Disconnect from the electrical supply before servicing the unit. Failure to do so
could result in death or electrical shock.
1. Disconnect the electrical supply to the
microwave oven.
LIFT DOOR PINS
OUT OF HINGE HOLES
2. Remove the two screws from the top of
the cabinet for the vent grille and remove
the grille (see the illustration on page 2-3).
3. Open the oven door all the way, then lift
the door pins out of the hinge holes and
remove it.
4. Install the new oven door and the vent
grille on the microwave oven.
PINS
HINGES
2-4
REMOVING THE OVEN DOOR COMPONENTS
WARNING
Personal Injury Hazard
Disconnect from the electrical supply before servicing the unit. Failure to do so
could result in death or electrical shock.
Cooking Products Service Manual
Original March, 1997 4322167
© 1997 Whirlpool Corporation
Page 2-5
4. To remove the oven door choke, use a
putty knife along the edges, and pry the
choke out from around the inside window
frame.
1. Disconnect the electrical supply to the
microwave oven.
2. Remove the two screws from the top of
the cabinet for the vent grille and remove
the grille (see the illustration on page 2-3).
3. Open the oven door all the way, then lift
the door pins out of the hinge holes and
remove it (see the illustration on the previous page).
SLOT
HOOKED TAB
GLASS
HOOK SPRING
OVER TABS
LATCHES
FRAME
OVEN DOOR
PRY OUT CHOKE
5. To replace the latches and door glass
assembly, remove the two mounting
screws from the end of the glass frame,
then push the top and bottom edges of the
door out and unsnap the locking tabs from
the frame and remove the assembly.
6. Slide the latches down and remove the
hooked tabs from the slots in the door
frame, then unhook the ends of the spring
from the door, and remove the latches.
7. Reassemble the oven door.
8. Reinstall the oven door and vent grille on
the microwave oven.
FRAME SCREWS
TOP LOCKING TABS
GLASS
FRAME
BOTTOM LOCKING TABS
2-5
REMOVING THE CONTROL PANEL
WARNING
Personal Injury Hazard
Disconnect from the electrical supply before servicing the unit. Failure to do so
could result in death or electrical shock.
2. Remove the two screws from the top of
the cabinet for the vent grille and remove
the grille (see the illustration on page
2-3).
3. Remove the screw from the top center tab
of the control panel, then lift the panel so
that the bottom tabs are out of the slots
and pull it forward.
1. Disconnect the electrical supply to the
microwave oven.
TURN PANEL OVER
CONTROL PANEL
4. Turn the panel over and disconnect the
three harness connectors from the board,
then set the control panel aside.
CONTROL
PANEL SCREW
BOTTOM
TABS
BOTTOM
SLOTS
2-6
REMOVING THE LINE FUSE
WARNING
Personal Injury Hazard
Disconnect from the electrical supply before servicing the unit. Failure to do so
could result in death or electrical shock.
Cooking Products Service Manual
Original March, 1997 4322167
© 1997 Whirlpool Corporation
Page 2-7
2. Remove the two screws from the top of
the cabinet for the vent grille and remove
the grille (see the illustration on page
2-3).
3. Remove the control panel from the microwave oven (see page 2-6).
4. From inside the control panel opening,
unsnap and open the fuseholder halves.
1. Disconnect the electrical supply to the
microwave oven.
CONTROL PANEL
OPENING
5. Remove the line fuse from the fuseholder
and pull the wire connectors off the ends.
6. Install the new line fuse and reassemble
the microwave oven.
2-7
SLIDE WIRE CONNECTORS
OFF ENDS OF FUSE
LINE FUSE
OPEN FUSEHOLDER
SECTIONS
FUSE HOLDER
REMOVING/ADJUSTING THE INTERLOCK SWITCHES
6. One at a time, pull the wire connectors off
WARNING
Personal Injury Hazard
Disconnect from the electrical supply before servicing the unit. Failure to do so
could result in death or electrical shock.
REMOVING A SWITCH
1. Disconnect the electrical supply to the
microwave oven.
2. Remove the two screws from the top of
the cabinet for the vent grille and remove
the grille (see the illustration on page
2-3).
3. Remove the control panel from the microwave oven (see page 2-6).
4. Remove the two mounting screws from
the interlock switch assembly, and position the assembly so you can easily access the switches and wiring.
5. Refer to inset 1 on the next page for the
secondary interlock switch, or inset 2 for
any of the other switches mounted on the
interlock switch housing assembly, and
remove the switch from the housing as
shown.
CONTROL PANEL
OPENING
the defective switch, and reconnect them
to the same terminals on the replacement
switch.
7. Snap the new switch into place on the
switch housing.
8. Mount the interlock switch assembly to
the chassis flange with two screws.
9. Close the housing cover and secure it
with its mounting screw.
MAKING ADJUSTMENTS
1. Plug in the microwave oven and check the
operation of the switches. If necessary,
loosen the two housing screws, and adjust the housing so that the switches operate properly. NOTE: The Interlock Monitor
Switch provides an added safety check on
the Primary and Secondary Interlock
Switches. If the Primary and Secondary
Interlock Switches allow the oven to operate with the door open, the Interlock Monitor Switch will blow the line fuse. Unplug
the oven again when you have completed
the checks.
2. Reassemble the microwave oven.
INTERLOCK
2-8
SCREW
INTERLOCK
SWITCH
HOUSING
INTERLOCK
SCREW
INSET 1
SECONDARY
INTERLOCK
SWITCH
INTERLOCK SWITCH
HOUSING ASSEMBLY
1.
RAISE THIS LOCKING
ARM TO RELEASE
SWITCH FROM HOUSING.
2.
PRESS BODY IN
THIS DIRECTION TO
REMOVE SWITCH
FROM HOUSING.
Cooking Products Service Manual
Original March, 1997 4322167
© 1997 Whirlpool Corporation
INSET 2
ALL OTHER
SWITCHES
NOTE: THESE POSTS
HOLD THE SWITCH IN
PLACE ON THE HOUSING
AND ARE STATIONARY.
SECONDARY INTERLOCK
SWITCH
1.
PUSH THIS LOCKING
ARM BACK TO UNLOCK
SWITCH.
2.
ROTATE SWITCH ON THIS
PIN AND REMOVE
SWITCH FROM HOUSING.
Page 2-9
WHITE (H.V. Transformer)
SMALL WHITE (Monitor Switch)
LARGE WHITE (Power Cord)
SMALL WHITE (Oven Lamp)
INTERLOCK MONITOR
PRIMARY INTERLOCK
SWITCH
SWITCH
WHITE (Turntable Motor)
WHITE (Secondary Switch)
RED (H.V. Transformer)
PINK (CN2 Pin 1)
Blue (CN2 Pin 3)
Interlock Switch Wiring
2-9
REMOVING THE BASE THERMAL FUSE
CONTROL PANEL
OPENING
YELLOW
PINK
WHITE
BASE
THERMAL FUSE
WARNING
Personal Injury Hazard
Disconnect from the electrical supply before servicing the unit. Failure to do so
could result in death or electrical shock.
2. Remove the two screws from the top of
the cabinet for the vent grille and remove
the grille (see the illustration on page
2-3).
3. Remove the control panel from the microwave oven (see page 2-6).
4. Remove the mounting screws from the
base thermal fuse and remove it.
1. Disconnect the electrical supply to the
microwave oven.
5. Unplug the connectors from the terminals
of the base thermal fuse.
6. Install the new base thermal fuse and
reassemble the microwave oven.
THE BASE THERMAL FUSE CLOSES
AT 133˚F & RESETS @ 104˚F.
2-10
Cooking Products Service Manual
Original March, 1997 4322167
© 1997 Whirlpool Corporation
Page 2-11
REMOVING THE MAGNETRON THERMAL FUSE
4. Unplug the line cord connector and re-
WARNING
Personal Injury Hazard
move the line cord.
5. Unplug the connector from the terminals
of the fan motor.
Disconnect from the electrical supply before servicing the unit. Failure to do so
could result in death or electrical shock.
1. Disconnect the electrical supply to the
microwave oven.
2. Remove the microwave oven from its
mounting location (see page 2-2).
3. Remove the vent grille and cabinet from
the microwave oven (see the illustration
on page 2-3).
REMOVE FIVE
AIR DUCT SCREWS
6. Remove the five screws from the air duct.
7. Lift the air duct and position it so that you
can access the magnetron thermal fuse,
then remove the mounting screw, and
unplug the connectors from its terminals.
8. Install the new magnetron thermal fuse
on the air duct, and reassemble the microwave oven.
BOTTOM
OF AIR DUCT
MAGNETRON
THERMAL FUSE
THE MAGNETRON THERMAL FUSE
OPENS AT 228˚F & RESETS @ 140˚F.
2-11
UNPLUG POWER
CORD & FAN MOTOR
BLACK & RED
WIRES
REMOVING THE CONVECTION THERMISTOR
WARNING
Personal Injury Hazard
Disconnect from the electrical supply before servicing the unit. Failure to do so
could result in death or electrical shock.
1. Disconnect the electrical supply to the
microwave oven.
2. Remove the microwave oven from its
mounting location (see page 2-2).
3. Remove the vent grille and cabinet from
the microwave oven (see the illustration
on page 2-3).
4. Remove the five screws from the air duct
and position it so that you can access the
pulley cover underneath.
5. Remove the screws from the circulation
pulley cover and the bracket, then remove the cover and the attached brackets from the top of the oven. Do not remove the brackets from the cover.
6. Remove the screw from the convection
thermistor and remove the thermistor.
7. Cut the two white wires (not the thermistor wires) coming from the control
board next to the splice.
8. Splice the white wires onto the ends of the
new convection thermistor wires. Cover
the spliced wire ends with electrical tape
so that they cannot short to the oven.
9. Mount the new convection thermistor to
the oven and reassemble the microwave
oven.
2-12
BRACKETS
Cooking Products Service Manual
Original March, 1997 4322167
© 1997 Whirlpool Corporation
CIRCULATION
PULLEY COVER
Page 2-13
SENSOR
COVER
PHILLIPS
SCREW
REMOVE FIVE
AIR DUCT SCREWS
WHITE WIRES
CAUTION: WHEN REPLACING THE
THERMISTOR, DO NOT CUT AND SPLICE
THE WHITE WIRES, OR AN IMPROPER
SIGNAL WILL BE SENT FROM THE THERMISTOR
TO THE MICROCOMPUTER BOARD
CONVECTION
THERMISTOR
2-13
REMOVING THE CAVITY THERMAL FUSE
3. Remove the vent grille and cabinet from
WARNING
Personal Injury Hazard
the microwave oven (see the illustration
on page 2-3).
4. Remove the five screws from the air duct.
Disconnect from the electrical supply before servicing the unit. Failure to do so
could result in death or electrical shock.
1. Disconnect the electrical supply to the
microwave oven.
2. Remove the microwave oven from its
mounting location (see page 2-2).
THE CAVITY THERMAL
FUSE OPENS AT 230˚F
CAVITY
THERMAL
FUSE
AIR DUCT
AND RESETS AT 140˚F
5. Unplug the connectors from the terminals
of the cavity thermal fuse, then lift the left
side of the air duct, and remove the cavity
thermal fuse. NOTE: There are no mounting screws holding the cavity thermal fuse
in place.
6. Install the new cavity thermal fuse in its
mounting hole, and reassemble the microwave oven.
REMOVE FIVE
AIR DUCT SCREWS
2-14
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