Sears Kenmore 767. 8514300 User manual

Department 731A Toronto
BASIC SERVICE MANUAL
MODEL 767. 8514300
MAY, 2002
FOR
MICROWAVE OVEN
TECHNICAL FLASH
T.F. 22-467
R

CAUTION
SAFETY PRECAUTIONS
PRECAUTIONS TO BE OBSERVED BEFORE AND
DURING SERVICING TO AVOID POSSIBLE EXPOSURE
TO EXCESSIVE MICROWAVE ENERGY
a. Do not operate or allow the oven to be operated with the door open.
b. Make the following safety checks on all ovens to be serviced before activating the
magnetron or other microwave source, and make repairs 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 CSA Standard should be
performed on each oven prior to release to the owner.
• Proper operation of the microwave ovens requires that the magnetron be assembled to the
wave guide 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.
• 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.

FOREWORD
Read this Manual carefully. Failure to adhere to or observe the information in this Manual may result in exposing
yourself to the Microwave Energy normally contained within the oven cavity.
TABLE OF CONTENTS (Page)
SAFETY PRECAUTIONS ......................................................................................................... Inside front page
SPECIFICATIONS.......................................................................................................................................... 1-1
CAUTIONS..................................................................................................................................................... 2-1
INSTALLATIONS............................................................................................................................................ 3-1
OPERATING INSTRUCTIONS....................................................................................................................... 4-1
CONTROL PANEL ................................................................................................................................. 4-1
CONTROL PANEL INSTRUCTIONS ..................................................................................................... 4-2
OVERALL CIRCUIT DIAGRAM...................................................................................................................... 5-1
SCHEMATIC DIAGRAM......................................................................................................................... 5-1
MATRIX CIRCUIT FOR TOUCH KEY BOARD...................................................................................... 5-2
GENERAL INFORMATION FOR SERVICE................................................................................................... 6-1
GENERAL PRECAUTIONS IN USE ...................................................................................................... 6-1
TRIAL OPERATION ............................................................................................................................... 6-1
FEATURES AND SPECIFICATIONS FEATURES................................................................................. 6-1
SERVICE INFORMATION ............................................................................................................................. 7-1
PRECAUTIONS AND REPAIR SERVICE TIPS..................................................................................... 7-1
MICROWAVE LEAKAGE TEST............................................................................................................. 7-2
POWER OUTPUT MEASUREMENT ..................................................................................................... 7-3
DISASSEMBLY INSTRUCTIONS .......................................................................................................... 7-4
INTERLOCK SYSTEM .......................................................................................................................... 7-12
INTERLOCK CONTINUITY TEST.......................................................................................................... 7-14
TEST AND CHECKOUT PROCEDURES AND TROUBLE SHOOTING................................................ 7-15
A. TEST PROCEDURES................................................................................................................ 7-15
B. CHECKOUT PROCEDURES..................................................................................................... 7-18
C. TROUBLE SHOOTING.............................................................................................................. 7-21
EXPLODED VIEW.......................................................................................................................................... 8-1
REPLACEMENT PARTS LIST............................................................................................................... 8-8
SCHEMATIC DIAGRAM OF PCB .......................................................................................................... 8-10
PRINTED CIRCUIT BOARD .................................................................................................................. 8-11
PCB PARTS LIST................................................................................................................................... 8-12

1-1
Rated Power Consumption 1,500W maximum (Microwave oven+Cook top lamps+Ventilation fan)
Microwave Output 1050W (IEC 60705)
Adjustable 100W through 1000W, 10 steps
Frequency 2,450 MHz + 50 MHz
Power Supply 120 VAC, 60 Hz
Rated Current 13 Amp. (Microwave oven+Cook top lamps+Ventilation fan)
Magnetron Cooling Forced Air Cooling
Rectification Rectification Voltage Double Half-Wave
Door Sealing Choke System
Safety Devices Magnetron Thermal Fuse:
Open at 109°C +
_ 4°C
Oven Cavity Thermostat:
Open at 110°C +
_ 5°C
Fuse(20A)
Primary Interlock Switch
Secondary Interlock Switch
Interlock Monitor
Magnetron 2M246-050GF or 2M248J
High Voltage Capacitor Capacitor: 1.0µF, 2.1 KV AC
High Voltage Diode Diode; 350mA, 9.0 KV
Cook top Lamp 125 V, 30 W
Cavity Lamp 125 V, 30 W
Timer Digital, up to 99 mim. 99 sec. (in each cooking stage)
Tray Tempered Safety Glass
Overall Dimensions 2915/16”(W)x167/16”(D)x155/8”(H)
Effective Capacity of Oven Cavity 1.9 Cu.ft.
Accessories Owner’s Manual & Cooking Guide, Installation Manual,
Exhaust Adapter, Exhaust Damper, Mounting Kit and Two Filters,
Rotating Ring Assembly, Metal Rack.
SPECIFICATIONS

2-1
CAUTIONS
• 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.
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

3-1
INSTALLATIONS
PRECAUTIONS ON INSTALLATION
A. Plug the power supply cord into a 120V AC, 60Hz,
single-phase power source with a capacity of 15A
or 20A.
B. Avoid placing the unit in a location where there is
direct heat or splashing water.
C. Install the unit on the mounting plate firmly.
D. Place the unit as far away as possible from TV,
radio, etc. to prevent interference.
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.
CAUTION
This unit is equipped with a 3-prong plug for your
safety. If the wall outlet is a grounded 3-hole type,
the unit will be grounded automatically.
Plug with Ground
Prong
Properly Polarized
and Grounded
Outlet

CONTROL PANEL
4-1
OPERATING INSTRUCTIONS

CONTROL PANEL INSTRUCTIONS
4-2
1. DISPLAY: The Display includes a clock and indicators to
tell you time of day, cooking time settings and cooking
functions selected.
2. QUICK TOUCH CONTROL (For model: 85130, 85138,
85139 only): Press these keys let you cook foods easily.
3. QUICK SENSOR (For model: 85140 only): Used to cook
common microwave-prepared foods without needing to
program times and cook powers.
4. MORE: Touch this pad to add ten seconds of cooking
time each time you press it.
5. LESS: Touch this pad to subtract ten seconds of cooking
time each time you press it.
6. HELP: Touch this pad to learn how to use each oven
function.
7. EXPRESS DEFROST: Meat, poultry, fish. Touch on pad
to select food type and defrost food by weight.
8. QUICK TOUCH PLUS: Touch this pad to set and start
quickly at 100% power.
9. QUICK DEFROST: This pad provides you with the quick
defrosting method for 1.0 pounds frozen foods.
10. NUMBER: Touch number pads to enter cooking time,
power level, quantities or weights.
11. TIME: Touch this pad to set a cooking time.
12. POWER: Touch this pad to select a cooking power level.
13. CUSTOM SET: Touch this pad to change the oven’s
default settings for sound, clock, display speed, defrost
weight, and demo mode operations.
14. HOLD WARM: Touch this pad to keep hot, cooked foods
safety warm in your microwave oven for up to 99 minutes
99 seconds.
15. TIME OF DAY: Touch this pad to enter the time of day.
16. CUSTOM COOK: Touch this pad to recall one cooking
instruction previously programmed into memory.
17. LIGHT TIMER: Touch this pad to set the light timer.
18. KITCHEN TIMER: Touch this pad to set the kitchen
timer.
19. STOP/CLEAR: Touch this pad to stop the oven or clear
all entries.
20. START: Touch this pad to start a function. If you open
the door after oven begins to cook, retouch START.
21. ON/OFF: Touch this pad to turn off the turntable.
“OFF” will appear in the display.
22. HI/LOW/OFF: Touch this pad to turn the fan on or
off.
23. HI/LOW/OFF: Touch this pad to turn on the
cooktop/countertop light.

5-1
A
B
C
SCHEMATIC DIAGRAM
OVERALL CIRCUIT DIAGRAM

MATRIX CIRCUIT FOR TOUCH KEY BOARD
5-2