Whirlpool 1997 "E THE GAS SENSOR

3-6

RD

WH

YL

RED

WHT

YEL

SENSOR

COVER MOUNTING

SCREW

GAS

SENSOR

BOARD

THE GAS SENSOR

TESTING

1. Set the ohmmeter to the

R x 1

scale.

2. Remove the 3-pin connector from

the control circuit board and mea-

sure the resistance between the:

a)Red & white wire terminals.

You should measure 20 Ω @

68˚F.

b)White & yellow wire terminals.

You should measure infinity.

The gas sensor is used during the “Sensor

Cook” operation of the oven. It is located

above the oven and is mounted on the left side

of the sensor cover. The sensor consists of

two circuits housed on a small microcomputer

board that is supplied with a current to keep it

heated. The sensor heat conductivity will vary,

depending upon the humidity of the oven.

Changing humidity conditions, due to the cook-

ing process within the oven cavity, causes a

difference in potential between these two cir-

cuits. This difference is monitored by the mi-

crocomputer during cooking, allowing the mi-

crocomputer to determine the proper cook

time.

NOTE: Always verify that the sensor cover is

not obstructed (proper air flow is passing over

the sensor), and that the fan motor is working

properly, before replacing the gas sensor.

Contents

Main Page TABLE OF CONTENTS iii Page iv IMPORTANT SAFETY INFORMATION Fire Hazard Electrical Shock Hazard WARNING NOTE CAUTION WARNING CAUTION WARNING TO SERVICE TECHNICIANS OR CAUTION WARNING R.F. LEAKAGE TEST CAUTION EQUIPMENT TEST THEORY OF OPERATION 1-2 N L1 3 1 11 N L1 3 1 13 COMPONENT SECTIONS COMPONENT ACCESS GENERAL REMOVING THE MICROWAVE OVEN & CABINET WARNING 2-3 Removing The Cabinet THE PROTECTION CONTROL SYSTEM REMOVING THE OVEN DOOR REMOVING THE OVEN DOOR COMPONENTS REMOVING THE CONTROL PANEL TURN PANEL OVER REMOVING THE LINE FUSE REMOVING/ADJUSTING THE INTERLOCK SWITCHES REMOVING A SWITCH MAKING ADJUSTMENTS 2-9 1997 Whirlpool Corporation INSET 1 Original March, 1997 4322167 Page 2-9 INSET 2 SECONDARY INTERLOCK REMOVING THE BASE THERMAL FUSE REMOVING THE MAGNETRON THERMAL FUSE REMOVING THE CONVECTION THERMISTOR 2-13 Page 2-13 REMOVE FIVE AIR DUCT SCREWS CONVECTION THERMISTOR WHITE WIRES REMOVING THE CAVITY THERMAL FUSE THE OPERATING CONTROL SYSTEM REMOVING THE OVEN LIGHT SOCKET REMOVING THE CONTROL CIRCUIT BOARD & THE TURNTABLE INDICATOR CIRCUIT BOARD TURN PANEL OVER INSET CONTROL BOARD REMOVING THE FAN MOTOR REMOVING THE POWER CORD POWER CORD REMOVING THE BLOWER MOTOR CAPACITOR REMOVING THE CONVECTION HEATING ELEMENT 2-21 Page 2-21 REMOVE FIVE AIR DUCT SCREWS VIEWED FROM UNDER TOP PLATE REMOVING THE GAS SENSOR REMOVING THE STIRRER MOTOR REMOVING THE TURNTABLE MOTOR REMOVING THE COOKTOP LIGHT SOCKETS THE HIGH VOLTAGE COMPONENTS ACCESSING THE COMPONENTS REMOVING THE MAGNETRON REMOVING THE HIGH VOLTAGE RECTIFIER AND THE HIGH VOLTAGE CAPACITOR REMOVING THE HIGH VOLTAGE TRANSFORMER Page CAUTION 3-1 Warning To Service Technicians! COMPONENT DESCRIPTION & TESTING IMPORTANT SAFETY INSTRUCTIONS Precautions to Avoid Possible Exposure to Excessive Microwave Energy 3-3 CAUTION WARNING THE THERMAL FUSES THE BLOWER MOTOR CAPACITOR R x 10K THE GAS SENSOR TESTING 1. Set the ohmmeter to the R x 1 THE CONVECTION THERMISTOR R x 10K THE CONVECTION HEATING ELEMENT TESTING 1. Set the ohmmeter to the R x 1 MOTORS Blower Motor Fan Motor Stirrer and Turntable Motors PROGRAMMING CHECKS f 2 f 1 CHARTS Page Page CHECKING THE MICROWAVE POWER OUTPUT CAUTION CHECKING FOR MICROWAVE ENERGY LEAKAGE EQUIPMENT MAKING THE MEASUREMENTS Measuring The Oven With The Cabinet Installed . Measuring The Oven With The Cabinet Removed MEASURING MICROWAVE POWER OUTPUT USING THE IEC-705 RATING STANDARD 3-18 TEST CHARTS R x 1000 COMPONENT TESTING WARNING ELECTRICAL SHOCK HAZARD 3-19 3-20 C. N.C. CONTACTS N.O. CONTACTS 3-21 KEYBOARD MATRIX 3-22 CONTROL CIRCUIT BOARD CHECK LIST 3-24 CONTINUITY TEST CHART DOOR OPEN DOOR CLOSED PRIMARY, MONITOR, & SECONDARY SWITCH CHECKOUT PROCEDURE (+) = CONTINUITY () = NO CONTINUITY 4-1 Page 4-1 11 TECH TIPS 1 CN1 CN5 321 321 1 2 3 1 2 3 Model MH9115XE CONTROL MODULE BK = Black BR = Brown RD = Red YL = Yellow GN = Green BL = Blue PK = Pink WH = White NOTES: 1. Oven is Off. 2. Door is Open. TEMP PROBE STRIP CIRCUITS N 2. DOOR IS OPEN OVEN LIGHT IS ON L1 1. UNIT IS PLUGGED IN CLOCK IS WORKING 4. BLOWER MOTOR IS ON HIGH 5. OVEN IS OFF CAVITY TEMPERATURE IS ABOVE 133F BLOWER MOTOR IS ON LOW 6. COOKTOP LIGHTS ARE ON HIGH OR LOW N L1 3 1 11 7. MICROWAVE COOKING IS ON 8. CONVECTION COOKING IS ON N L1 SPECIFICATIONS 4-7 Page 4-7 SPECIFICATION CHARTS 4-8 4-9 Page 4-9 4-10 4-11 Page 4-11 4-12 4-13 Page 4-13 4-14 4-15 MODEL & SERIAL NUMBER EXPLANATION SERIAL PLATE LOCATION 4-16 WHIRLPOOL MICROWAVE HOOD WARRANTY LENGTH OF WARRANTY WHIRLPOOL WILL PAY FOR: WHIRLPOOL WILL NOT PAY FOR: