Thermador CM301B, CM301W, CM302W, CM302S, CM301S Service Manual

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Page 1

SERVICE MANUAL

for

THERMADOR

BUILT-IN OVENS

MODELS:

Lit. No. 94-30-006B

Model CM302S

CM301B / CM301W / CM301S CM302B / CM302W / CM302S

August, 2000

Page 2

CM Oven Service Manual Lit. No. 94-30-006B

Table of Contents

General ............................................................................. 1-8

Data Plate Location ........................................................ 1

Symbols You Will See In The Manual ............................ 2

Avoid Exposure To Excessive Microwave Energy......... 3

Cautions To Observe When Troubleshooting ................ 4

Avoid Electrical Shock .................................................... 5

Measuring For Microwave Radiation Leakage............6-7

Thermador Warranty....................................................... 8

Servicing Components ..................................................... 9

Component Locations.......................................................... 9

Removing Trim, & Top Plenum Covers............................. 10

Removing Electronic Oven Control Board ........................ 11

Removing Fuseblock & Microwave PCB Control.............. 12

Removing Light Transformer

& Double Line Break Relay ............................................... 13

Removing Stirrer Motor ..................................................... 1 4

Removing Transformer Cooling Fan & Microwave

Transformer Air Switch Assembly ..................................... 15

Removing Magnetron Fan Assembly ................................ 1 6

Removing Crossflow Top Cooling Blower......................... 17

Removing High Voltage Microwave Capacitor.................. 18

Removing High Voltage Diode .......................................... 19

Removing High Voltage Microwave Transformer ........ 20-21

Removing Magnetron, & Magnetron Thermal Cutout .. 22-23 Removing Control Panel Assembly,

Display Board, & Touch Panel Glass ................................ 24

Removing Upper (Or Single) Oven Door Switch .............. 25

Removing Door Latch Assembly, High-Temp Cutout, &

Monitor & Secondary Switch Assembly ....................... 26-27

Removing A Halogen Light Assembly.......................... 28-29

Removing Broil Element & Stirrer Blade Assembly ..... 30-31

Removing Waveguide .................................................. 32-33

Removing Convection Element & Motor ...................... 34-36

Removing Meat Probe Jack .............................................. 37

Removing Hidden Bake Element ................................. 38-39

Removing Oven Thermal Sensor ...................................... 40

Removing Upper (Or Single) Oven Door Gasket.............. 41

Removing, Reinstalling Microwave Oven Door............ 42-44

Removing Upper (Or Single) Oven Door Handle & Outer

Glass Assembly ................................................................. 45

Removing An Oven Door Hinge, Actuator Arm, Center

Glass, RF Screen, & Inner Glass ................................. 46-48

Troubleshooting ................................................................. 49

Testing Components, 20A Time-Delay Fuse ............... 49

Transformer Cooling Fan Motor ................................... 49

Light Transformer, Double Line Break Relay ............... 50

Stirrer Motor, High Voltage Diode ................................ 51

High Voltage Capacitor, High Voltage Transformer..... 52

Magnetron, Magnetron Thermal Cutout (TCO) ............ 53

Magnetron Fan Motor, Crossflow Blower Motor .......... 54

Door Latch Assembly, Monitor & Secondary Switches 55

Door Switch, Oven Thermal Sensor............................. 56

Broil Element, Bake Element........................................ 57

Convection Element, Convection Motor ....................... 58

M/W Transformer Air Switch, Meat Probe Jack ........... 59

Microwave PCB Control................................................ 60

Microwave Components Description ....................... 61-67

Interlock Switches.............................................................. 62

Latch Mounted switch........................................................ 62

Oven Mounted switches .................................................... 63

Switches Activated by Hook .............................................. 64

20-Ampere Fuse, Fuse Failure.......................................... 65

Diode, High Voltage Transformer, Magnetron Tube......... 66

Microwave Board, Stirrer Motor, Microwave

Transformer Cooling Fan & Air Switch.............................. 67

CM Lower Oven ....................................... 68-108

CM Relay Board Matrix ..................................................... 6 9

CM DAC Relay Board................................................... 70-73

Wire Harnesses ............................................................ 74-75

Troubleshooting Chart for

Relay Board Headers Pin Failures............................... 76-77

CM Oven Control Panel..................................................... 78

Electronic Oven Controls................................................... 79

Control Panel Assembly .................................................... 80

Glass Touch Panel ............................................................ 81

Display Head ..................................................................... 82

Troubleshooting Chart for

Display Head Pin Failures ................................................. 83

CM Lower Oven Illustration ............................................... 84

Removing Hidden Bake Element ................................. 85-86

Removing Oven Temperature Sensor .............................. 87

Removing Convection Bake Element................................ 88

Removing Convection Fan Motor................................. 89-90

Removing Halogen Lamp Holder ...................................... 91

Removing Lamp Transformer &

Lower Oven Double Line Break Relay .............................. 92

Removing Oven Light Switch, Oven Door Latch

Assembly and High Temp Cut-out ............................... 93-94

Removing Air Switches................................................. 95-96

Removing a Blower ...................................................... 97-98

Removing Lower Oven Door ............................................. 99

Removing Oven Door Gasket ......................................... 100

Removing Oven Door Components ................................ 101

Removing Oven Module .................................................. 102

Troubleshooting ............................................................... 103

Blower Motor, Air Switch ............................................ 103

Convection Fan Motor, Lamp Transformer ................ 104

Oven Door Latrch Assembly....................................... 105

Hidden Bake Element, Broil Element ......................... 106

Convection Bake Element, Hi-Temp Cutout .............. 107

Fault Codes ..................................................................... 108

Schematic & Wiring Diagrams ............... 109-113

CM301 Schematic Diagram........................................ 109

CM301 Wiring Diagram .............................................. 110

CM302 Schematic Diagram........................................ 111

CM302 Wiring Diagram .............................................. 112

CM301 Electronic Oven Control Wiring...................... 113

CM302 Electronic Oven Control Wiring...................... 113

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CM Oven Service ManualLit. No. 94-30-006B

“CM” Oven Service Manual

THE CM OVEN SERVICE MANUAL CONTAINS INFORMATION THAT IS NECESSARY FOR SERVICING THE THERMADOR

CM301B / CM301W / CM301S CM302B / CM302W / CM302S

THIS MANUAL IS DESIGNED TO BE USED ONLY BY QUALIFIED SERVICE PERSONNEL. THERMADOR RECOMMENDS THAT CUSTOMERS THEIR OWN UNITS, DUE TO THE COMPLEXITY AND THE RISK OF HIGHVOLTAGE ELECTRICAL SHOCK.

THE INFORMATION IS ORGANIZED TO HELP THE SERVICER EASILY FIND WHAT IS NEEDED TO REPAIR THE UNIT.

BUILT-IN OVEN MODELS:

DO NOT SERVICE

GENERAL

DATA PLATE LOCATION

Data Plate (behind oven

cooling vent, right side)

Page 1

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CM Oven Service Manual Lit. No. 94-30-006B

CAUTION

SYMBOLS YOU WILL SEE IN THE MANUAL

The following symbols are provided throughout this manual. For reasons of personal safety

WARNING

This symbol alerts you to such dangers as personal injury, burns, fire, and electrical shock.

Tech Tip !!

This symbol alerts you to a service tip or a special procedure.

and proper operation and servicing of the oven, follow the instructions carefully each time you see one of the symbols.

This alerts you to actions that could cause product damage (scratches, dents, etc.), and damage to your personal property.

Service

Alert !!

This symbol alerts you to check for microwave radiation leakage and to record the reading on the service repair ticket while in the customers.

THERMADOR ASSUMES NO RESPONSIBILITY FOR ANY REPAIRS MADE ON OUR PRODUCTS BY ANYONE OTHER THAN AUTHORIZED THERMADOR SERVICE TECHNICIANS.

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CM Oven Service ManualLit. No. 94-30-006B

TO AVOID EXPOSURE TO

EXCESSIVE MICROWAVE ENERGY

Observe these precautions before and during servicing:

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, waveguide, 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 generating and transmission systems shall be repaired, replaced, or adjusted by procedures described in this manual before the oven is released to the owner.

WARNING

This product should be serviced

only by trained qualified personnel.

5. Although this product has been manufactured in compliance with “FDA Radiation Performance Standards, 21 CFR Subchapter J,” it is very important that all repairs should be made in accordance with procedures described in this manual to avoid being exposed to excessive microwave radiation.

6. Check for radiation leakage before and after every servicing. Refer to ”Measuring For Microwave Radiation Leakage” on Page 6.

7. Certain components used in the microwave oven are important for safety. It is essential to replace these critical parts only with manufacturer’s specified parts to prevent microwave leakage, shock, fire, or other hazards. Do not modify the original design.

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CM Oven Service Manual Lit. No. 94-30-006B

CAUTIONS TO OBSERVE WHEN TROUBLESHOOTING

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

CAUTION

Remove your wristwatch when working close to or when replacing the magnetron.

1. Check the grounding. The microwave oven is designed to be used when grounded. Make sure it is grounded properly before beginning repair work.

2. Discharge the electric charge in the high-voltage capacitor. For about 30-seconds after the oven stops, an electric charge remains in the high-voltage capacitor. When replacing or checking parts, short between the oven chassis and the terminal of the high-voltage capacitor (terminals of lead wire from magnetron filament, high-voltage transformer filament lead wire, and diode lead wire) with an insulated screwdriver to discharge.

WARNING

There is high-voltage present, with high current capabilities, in the circuits of the high-voltage winding and filament winding of the high-voltage transformer. It is extremely dangerous to work on or near these circuits with the oven energized.

Do not measure the voltage in the high-voltage circuit, including the filament voltage of the magnetron.

Never touch any circuit wiring with your hand or with an insulated tool during operation.

3. When parts must be replaced, disconnect the power to the unit.

4. Avoid inserting nails, wire, etc. through any holes in the unit during operation. Never insert a wire, nail, or any other metal object through the lamp holes on the cavity or any other holes or gaps, because such objects may work as an antenna and cause microwave leakage.

5. Confirm after repair. After repairing or replacing parts, make sure that the screws of the oven, etc., are neither loose or missing. Microwaves might leak if screws are not properly tightened.

6. Make sure that all electrical connections are tight.

7. Check for microwave energy leakage. Refer to “Measuring For Microwave Radiation Leakage” on Page 6.

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WARNING

To Avoid Electrical Shock:

CM Oven Service ManualLit. No. 94-30-006B

• Disconnect the power to the appliance before servicing.

• For those checks requiring the use of electrical power, exercise extreme car e.

• Do not attempt high-voltage tests.

RESPECT HIGH-VOLTAGE

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CM Oven Service Manual Lit. No. 94-30-006B

PROCEDURE FOR MEASURING

MICROWAVE RADIATION LEAKAGE

Before performing any tests, be sure to observe

WARNING

Check for microwave radiation leakage before and after every servicing. Should the leakage be more than 5 mw/cm2 inform Thermador immediately. After repairing or replacing any radiation safety device, keep a written record for future reference, as required by D.H.H.S. regulations. This requirement must be strictly observed. In addition, the leakage reading must be recorded on the service repair ticket while in the customer’s home.

the following precautions:

• Do not exceed the meter’s full-scale deflection. Leakage monitor should initially be set to the highest scale.

• To prevent false readings, hold the test probe by the grip portion of the handle only, and move it along the shaded area shown in the following illustration.

• Meter reading with the top panel removed should be less than 4 mw/cm2.

• Meter reading for fully assembled oven, with the door normally closed should be

less than 4 mw/cm2.

• Meter reading for fully assembled oven, before the latch switch (primary) is interrupted while lightly pulling on the

door, should be less than 4mw/cm2.

NOTE: The maximum allowable leakage according to U.S. Government standard is 5 mw/cm while in the customer’s home. Using 4mw/cm2 as the highest acceptable meter reading, allows for meter and probe accuracy tolerances.

Equipment:

Holaday model 1501 or equivalent meter. Glass thermometer, 212° F. or 100° C. 600 cc glass beaker.

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CM Oven Service ManualLit. No. 94-30-006B

PROCEDURE FOR MEASURING

MICROWAVE RADIATION LEAKAGE, continued

Avoid contacting any high-voltage parts.

I. Pour 275 ± 15 cc (9 oz. ± 1/2 OZ.) of 20 ±

5ºC (68 ± 9ºF) water in a beaker,

graduated to 600 cc, and place the beaker in the center of the oven.

2. Set the radiation monitor to 2450 MHz,

and follow the manufacturer’s recommended test procedure to assure correct results.

NOTE: When measuring the leakage, always use the 2 inch (5 cm) spacer supplied with the probe.

3. Start the magnetron and measure the leakage by holding the probe

perpendicular to the surface being measured.

4. Measuring With The Top Panel Removed — Whenever you replace the magnetron, measure for radiation leakage before the top panel is installed and after all necessary components are replaced or adjusted. Special care should be taken in measuring around the magnetron.

WARNING

5. Measuring A Fully Assembled Oven

After all components, including the top panel, are fully assembled, measure for radiation leakage around the (door periphery and the door viewing window .

6. Record keeping and notification after measurement. Take a leakage reaching

after any adjustment or repair to a microwave oven. Record this leakage on the repair ticket, even if it is zero. A copy of this repair ticket and the microwave oven leakage reacting should be kept by the repair facility.

If the radiation leakage is more than 5mw/cm2 after determining that all parts are in good condition and functioning properly, and that genuine replacement parts, as listed in this manual, have been used, immediately notify Thermador and inform the owner that the microwave cannot be used.

7. At least once a year, have the radiation monitor calibrated by its manufacturer .

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CM Oven Service Manual Lit. No. 94-30-006B

THERMADOR® WARRANTY

Length of Warranty FULL ONE YEAR

For one year from date of installation or date of occupancy for a new previously unoccupied dwelling. Save all dated receipts or other evidence of date of installation/occupancy date.

Thermador will pay for:

All repair labor and replacement parts found to be defective due to materials and workmanship. Service must be provided by a Factory Authorized Service Agency, during normal working hours. For a Service Agency nearest you, please call: 1-800/735-4328.

Thermador will not pay for:

1. Service by an unauthorized agency. Damage or repairs by an unauthorized agency or use of unauthorized parts.

2. Service visits to:

• Teach you how to use the

appliance.

• Correct the installation.

You are responsible for providing electrical wiring and/or gas installation and other connecting facilities.

• Reset circuit breakers or

replace home fuses.

3. Damage caused from accident, abuse, alteration, misuse, incorrect installation or installation not in accordance with local codes, or improper storage of the appliance.

4. Repairs due to other than normal home use.

This warranty applies to appliances used in normal family households; it does not cover their use in commercial situations.

This warranty is for products purchased and r etained in the 50 states of the U.S.A., the District of Columbia, and Canada. The warranty applies even if you should move during the warranty period. Should the appliance be sold by the original purchaser during the warranty period, the new owner continues to be protected until the expiration of the original purchaser’s warranty period.

THERMADOR DOES NOT ASSUME ANY RESPONSIBILITY FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES. Some states do not allow the exclusions or limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you. This warranty gives you specific legal rights. You may also have other rights which vary from state-tostate or province-to-province.

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SERVICING THE COMPONENTS

COMPONENT LOCATIONS

CM Oven Service ManualLit. No. 94-30-006B

The serviceable components for the upper (or single) oven and plenum are included in this section of the manual. The components are

Crossflow Top Cooling Blower

HV M/W Capacitor

HV M/W Transformer

HV Diode

Transformer Cooling Fan & M/W Transformer Air Switch

Microwave PCB Control

Fuse & Fuseblock

TOP PLENUM COMPONENTS

shown below . Refer to the pages that show the components you wish to service.

Magnetron Thermal Cutoff

Magnetron & Waveguide

Stirrer Motor

Double Line Break Relay

Magnetron Fan Assembly

Light Transformer

Electronic Oven Control Board

Door Latch Assembly

Broil Element

Convection Element

Halogen Light (2)

Hidden Bake Element

High-Temp Cutout

FRONT COMPONENTS

Control Panel

Door Switch

Monitor & Secondary Switch Assembly

Stirrer Blade

Oven Thermal Sensor

Convection Motor

Meat Probe Jack

UPPER (OR SINGLE) OVEN COMPONENTS

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CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE TRIM, AND TOP PLENUM COVERS

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. Pull the oven out of its mounting location so that you can access the trim and plenum covers.

3. To remove the trim, remove the two end

screws.

4. To remove the top front plenum cover:

a) Remove the five screws. b) Pull the cover forward and remove it.

5. To remove the top rear plenum cover, re-

move the eight screws and lift it off the oven.

Top Front

Plenum Cover

(5 screws)

Trim

(2 Screws)

Top Rear

Plenum Cover

(8 screws)

Page 10

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CM Oven Service ManualLit. No. 94-30-006B

REMOVING THE ELECTRONIC OVEN CONTROL BOARD

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. Turn off the electrical power going to the oven.

2. Pull the oven out of its mounting location so that you can access the trim and plenum covers.

3. Remove the trim and top plenum covers from the oven (see Page 10).

4. Remove the four screws from the control panel mounting bracket, pull the catches out of the ball studs at each end of the bracket, (see the small inset), and remove the bracket from the oven.

6. Remove the six screws from the electr onic oven control board.

3 Screws

7. Lift the front of the electronic oven control board and slide the thr ee wire ties of f the front spacers, then remove the board from the oven.

Tie

Ball Stud

2 Screws

Control Panel

Mounting Bracket

5. Disconnect the wires from the electronic oven control board connectors.

Catch

2 Screws

Tech T ip!!

If necessary, refer to Page 113 for the wire connection callouts for single and double electronic oven control boards.

Page 11

Page 14

CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE FUSEBLOCK

& MICROWAVE PCB CONTROL

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. Pull the oven out of its mounting location so that you can access the trim and plenum covers.

3. Remove the trim and top plenum covers from the oven (see Page 10).

4. Remove the control panel mounting bracket (see Step 4 on Page 11).

5. To remove the fuseblock:

BK-126

20 Amp

Fuse

BK-125

Screw

6. To remove the microwave PCB control:

a) Disconnect the wires from the termi-

nals.

b) Remove the four mounting screws

from the bracket.

Screws

3 White

a) Pull the fuse out of the clips. b) Remove the mounting screw from the

center of the fuseblock.

Microwave

PCB Control

Fuse &

Fuseblock

4 Screws

BK 127

BK 130

2 Y ellow 2 Orange

Screws

Page 12

Page 15

REMOVING THE LIGHT TRANSFORMER

& DOUBLE LINE BREAK RELAY

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. Turn off the electrical power going to the oven.

2. Pull the oven out of its mounting location so that you can access the trim and plenum covers.

3. Remove the trim and top plenum covers from the oven (see Page 10).

CM Oven Service ManualLit. No. 94-30-006B

YL-82

YL-84 YL-85 YL-18

RD-81WH-19

YL-83

YL-141

5. To remove the upper (or single) oven double line break relay:

a) Disconnect the wires from the r elay ter-

minals.

b) Remove the two screws.

4. To remove the light transformer:

a) Disconnect the wires from the termi-

nals.

b) Remove the two mounting screws from

the bracket.

Screw

Double Line

Break Relay

YL-20 BU-21 OR-22

Screw

BK YL 34 10

YL 09

Screw

Light

Transformer

Screw

Page 13

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CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE STIRRER MOTOR

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. Pull the oven out of its mounting location so that you can access the trim and plenum covers.

3. Remove the trim and top plenum covers from the oven (see Page 10).

4. Disconnect the stirrer motor wires from the terminal block and the in-line connector .

Stirrer Motor Wires

5. Remove the two mounting screws from the stirrer motor bracket, lift the motor, and slide the coupling out of the stirrer blade receptacle.

Screw

Stirrer Motor

Screw

Motor Coupling

Stirrer Blade Receptacle

In-line Connector Terminal Block

Page 14

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CM Oven Service ManualLit. No. 94-30-006B

REMOVING THE TRANSFORMER COOLING FAN

AND M/W TRANSFORMER AIR SWITCH ASSEMBLY

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. Turn off the electrical power going to the oven.

2. Pull the oven out of its mounting location so that you can access the trim and plenum covers.

3. Remove the trim and top plenum covers from the oven (see Page 10).

4. To remove the transformer cooling fan: a) Disconnect the wires from the termi-

nals.

b) Remove the two plenum mounting

screws from the bracket.

c) Remove the four fan mounting screws

from the bracket.

M/W Transformer Air Switch

Screws

5. To remove the m/w transformer air switch assembly from the transformer cooling fan:

a) Remove the transformer cooling fan

from the plenum (see Step 4).

b) Disconnect the wires from the termi-

nals.

c) Remove the two mounting screws from

the switch body.

M/W Transformer Air Switch

Plenum

Screw

Transformer Cooling Fan

Wires

BU-163

WH-164

Plenum

Screw

WH-102

WH-103

2 Screws

Page 15

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CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE MAGNETRON FAN ASSEMBLY

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. Pull the oven out of its mounting location so that you can access the trim and plenum covers.

3. Remove the trim and top plenum covers from the oven (see Page 10).

4. Disconnect the wires from the terminals of the magnetron fan assembly.

5. Remove the two fan assembly bracket screws from the plenum and remove the assembly.

6. Remove the two duct screws and slide it off the fan assembly.

WH-24 WH-162

BU-23 WH-94

2 Duct

Screws

DUCT

Bracket Screws

Magnetron Fan Assembly

Page 16

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CM Oven Service ManualLit. No. 94-30-006B

REMOVING THE CROSSFLOW TOP COOLING BLOWER

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. Turn off the electrical power going to the oven.

2. Pull the oven out of its mounting location so that you can access the trim and plenum covers.

3. Remove the trim and top plenum covers from the oven (see Page 10).

4. Disconnect the wires from the terminals of the crossflow top cooling blower.

5. Remove the two screws from the blower mounting bracket and remove the blower from the oven.

Bracket Screws

WH75

SH162

WH-164

BU-74 BU-161 BU-163

Crossflow Top

Cooling Blower

Page 17

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CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE HIGH VOLTAGE

MICROWAVE CAPACITOR

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. Pull the oven out of its mounting location so that you can access the trim and plenum covers.

3. Remove the trim and top plenum covers from the oven (see Page 10).

4. CAUTION: DISCHARGE THE HIGH

VOL T AGE MICROWA VE CAP ACITOR WITH A 20,000 OHM, 1- OR 2-WATT RESISTOR TO CHASSIS GROUND BEFORE WORKING ON ANY OF THE HIGH VOLTAGE COMPONENTS. BE VER Y CAREFUL NOT TO TOUCH THE BARE RESISTOR LEADS WHEN YOU DISCHARGE THE CAPACITOR.

5. Disconnect the wires from the terminals of the high voltage microwave capacitor.

6. Remove the capacitor mounting bracket screw and remove the bracket and capacitor from the transformer side shield.

High V oltage

Microwave Capacitor

Transformer

Side Shield

Bracket

Screw

TAN-Transformer

Secondary Lead

OR-135 OR-136

Touch Resistor

Lead To Chassis

Touch Resistor

Lead T o Capacitor

T erminal

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CM Oven Service ManualLit. No. 94-30-006B

Cathode (–)

Anode (+)

REMOVING THE HIGH VOLTAGE DIODE

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. Pull the oven out of its mounting location so that you can access the trim and plenum covers.

3. Remove the trim and top plenum covers from the oven (see Page 10).

4. CAUTION: DISCHARGE THE HIGH

VOL T AGE MICROW AVE CAP ACITOR WITH A 20,000 OHM, 1- OR 2-WATT RESISTOR TO CHASSIS GROUND (SEE P AGE 18) BEFORE WORKING ON ANY OF THE HIGH VOLTAGE COMPONENTS. BE VERY CAREFUL NOT TO TOUCH THE BARE RESISTOR LEADS WHEN YOU DISCHARGE THE CAP ACITOR.

5. Disconnect the wires from the terminals of the high voltage diode.

6. Remove the mounting screw from the diode and remove the diode from the shield.

Screw

HV Diode

GN-134

OR-135

Tech T ip!!

IMPORTANT: Make sure that you position

the high voltage diode with the cathode (–) terminal at the top and the anode (+) terminal at the bottom. The diode symbol is shown below and on the side of the diode body.

Page 19

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CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE HIGH VOLTAGE

MICROWAVE TRANSFORMER

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. Pull the oven out of its mounting location so that you can access the trim and plenum covers.

3. Remove the trim and top plenum covers from the oven (see Page 10).

4. CAUTION: DISCHARGE THE HIGH

6. Remove the four mounting screws from the heat sink bracket and remove the bracket from the top of the transformer.

Heat Sink

Screw

Screw Screw

7. Remove the two mounting screws from the heat sink and remove the sink from the top of the transformer.

Bracket

Screw

Heat Sink2 Screws

5. Disconnect the three high voltage microwave transformer leads from the terminals of the high voltage capacitor and the magnetron.

OR-136 & OR-Filament Lead

OR-Filament

Lead

Tan-Secondary

Lead

BK-131

WH-132

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CM Oven Service ManualLit. No. 94-30-006B

8. Remove the four mounting screws from the high voltage microwave transformer and remove the transformer from the oven.

Screw (1 of 4)

9. Remove the heat sink plate from the top of the high voltage microwave transformer.

10. Apply a liberal amount of heat sink paste over the top of the new transformer, then place the heat sink plate in the center of the transformer and press it down so it adheres firmly.

Heat Sink Paste

Heat Sink Plate

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CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE MAGNETRON, &

MAGNETRON THERMAL CUTOUT

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. Pull the oven out of its mounting location so that you can access the trim and plenum covers.

3. Remove the trim and top plenum covers from the oven (see Page 10).

4. CAUTION: DISCHARGE THE HIGH

VOL T AGE MICROWA VE CAP ACITOR WITH A 20,000 OHM, 1- OR 2-WATT RESISTOR TO CHASSIS GROUND (SEE P AGE 18) BEFORE WORKING ON ANY OF THE HIGH VOLTAGE COMPONENTS. BE VERY CAREFUL NOT TO TOUCH THE BARE RESISTOR LEADS WHEN YOU DISCHARGE THE CAP ACITOR.

6. To remove the magnetron:

a) Disconnect the wires fr om the two ter-

minals.

b) Remove the two screws from the vent

cover and remove the cover.

Screw

OR-Filament

c) Remove the mounting screws (two

each) from the left and right waveguide insulation covers and remove the covers.

OR-136 & OR-Filament

Screw Vent Cover

5. Remove the two screws from the magnetron fan duct and remove the duct.

Fan Duct 2 Screws

Screws

Page 22

Left Insulation

Cover

Screws

Right Insulation

Cover

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CM Oven Service ManualLit. No. 94-30-006B

d) Remove the two pieces of insulation

from the top of the waveguide.

Insulation Insulation

e) Remove the four mounting screws

from the magnetron and lift it off the waveguide.

Screw

c) Repeat steps a and b for screws #3 and

#4 so that all four screws are loosely installed.

d) Alternately tighten screws #1 through

#4 until they are snug. The base of the magnetron should be perfectly parallel with the waveguide to operate properly .

8. To remove the magnetron thermal cutout:

Screw Screw

7. To reinstall the magnetron on the waveguide, use the cross-tightening

method to tighten the four screws, as follows:

a) Loosely install screw #1. b) Loosely install screw #2 in an alternate

(across the transformer) mounting hole.

a) Disconnect the wires (BK-130 & BK131)

from the terminals.

b) Remove the two screws.

Screw

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CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE CONTROL PANEL ASSEMBLY,

DISPLAY BOARD, & TOUCH PANEL GLASS

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. Open the microwave oven door.

3. To remove the control panel assembly: a) Remove the four outer black screws

from the bottom of the control panel assembly.

c) Disconnect the cables from the touch

panel glass filter board connectors.

d) Remove the nine indicated screws from

the control panel plate and lift the plate off the control panel.

4 Top Control Panel Plate Screws

Cables

5 Bottom Control Panel Plate Screws

e) Lift the display board off the control

panel.

Display Board Touch Panel Glass

4 Black Control Panel Screws

b) Pull the top of the control panel for-

ward and unhook the two ball studs at the top right and left corners from the catches.

c) Disconnect the five cables from the con-

trol panel board connectors at P2, P4, P6, P10, and P11 and r emove the assembly .

4. To remove the display board and touch

panel glass:

a) If not already done, remove the con-

trol panel assembly from the oven (see Step 3).

b) Place the control panel assembly face-

down on a padded work surface to prevent scratching the finish.

f) Remove the screws from the mounting

brackets and remove the brackets from the display board.

Bracket Screws

g) Lift the touch panel glass (with filter

boards) out of the control panel frame.

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CM Oven Service ManualLit. No. 94-30-006B

REMOVING THE UPPER (OR SINGLE)

OVEN DOOR SWITCH

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. Open the microwave oven door.

3. Remove the four outer black screws from the bottom of the control panel assembly (see Step 3, Page 24).

4. Remove the two black screws that are holding the upper latch plate to the front of the upper door latch assembly.

5. Pull the upper latch plate forward and push the oven door switch out of the mounting hole.

6. Disconnect the wires from the oven door switch.

WH-03

Oven Door Switch

WH-04

Upper Latch

Plate

2 Black Screws

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CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE DOOR LATCH ASSEMBLY,

HIGH-TEMP CUTOUT, AND THE MONITOR &

SECONDARY SWITCH ASSEMBLY

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. Open the microwave oven door.

3. Remove the four outer black screws from the bottom of the control panel assembly.

7. Disconnect the five cables from the touch glass filter board connectors at P2, P4, P6, P10, and P11 and r emove the control panel assembly .

NOTE: The door latch assembly and the monitor and secondary switch assembly must each be replaced as an assembly. Individual parts are not available.

8. To remove the door latch assembly: a) Use an angled 1/4˝ socket and remove

the two hex-head screws from the fr ont of the door latch assembly. Pull the assembly forward as far as the wires will allow .

b) Disconnect the wires from the latch

motor and switches.

Latch Motor

Wires

2 Switches

4 Black Control Panel Screws

4. Remove the two black screws that are holding the upper latch plate to the front of the upper door latch assembly.

Upper Latch

Plate

5. Pull the upper latch plate forward and position it off to the side.

6. Pull the top of the control panel forward and unhook the two ball studs at the top right and left corners from the catches.

2 Black Screws

High-Temp

Cutout

Door Latch

Assembly

2 Hex-Head Screws

NOTE: The M/W oven door latch motor is activated by 12-volts D.C. through a series of diodes on the electronic oven control boar d (see Page 60). This motor locks the microwave oven door faster than the lower oven motor.

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CM Oven Service ManualLit. No. 94-30-006B

9. To remove the high-temp cutout:

a) Use an angled 1/4˝ socket and remove

the two hex-head screws from the high-temp cutout bracket. Pull the cutout forward as far as the wires will allow.

b) Disconnect the wires from the termi-

nals.

High-Temp

Cutout

BK-33

BK-34

10. To remove the monitor and secondary switch assembly:

a) Use an angled screwdriver and remove

the four screws and lockwashers from the switch assembly . Pull the assembly forward as far as the wires will allow.

b) Disconnect the wires from the switch

terminals.

BK-128 & WH-129 WH-132 & WH-133

Screw & Lockwasher

(1 of 4)

Hex-Head Screws

Secondary Switch Monitor Switch

Page 27

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CM Oven Service Manual Lit. No. 94-30-006B

REMOVING A HALOGEN LIGHT ASSEMBLY

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. To make servicing inside the oven easier, remove the microwave oven door (see Page 42 for the procedure).

6. Remove the screws from the metal scr een that is over the halogen light and remove the screen.

Screw (1 of 4)

Lens Holder & Lens

3. Remove the oven racks.

4. Remove the screws from the rack support that is over the halogen light you wish to service.

Screws

Rack Support

Screws

Stop

CAUTION: When you remove the halogen lens holder and lens in the next step, be careful that the lens does not fall out and break.

5. Remove the four screws from the halogen lens holder and remove the holder and lens from the oven liner.

Screw (1 of 16)

Metal Screen

7. Pull the light assembly out of the oven liner cutout and remove the halogen bulb from the socket.

Cut Leads Here

Halogen Bulb

Light Assembly

8. Cut the leads that are coming from the light socket near the socket body.

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Page 31

9. Cut the leads of the new light assembly approximately 3˝ from the body.

10. Remove 3/8˝ of insulation from the cut lead ends and the wiring harness.

11. Twist two small wire nuts over the ends of the leads.

CM Oven Service ManualLit. No. 94-30-006B

Tech T ips!!

When you reassemble the halogen light assembly:

1. Position the wiring neatly inside the oven liner cutout for the halogen light and press the assembly into place so its edges are flush with the outside of the liner.

Keep Edges

Flush With Liner

Install Halogen Bulb

2. Install the bulb in the socket.

3. When you reinstall the metal screen, do not install screws at the four corners (see Step 6 on the previous page).

4. When you reinstall the rack support, make sure you position it with the stop towards the back (see Step 4 on the previous page).

Page 29

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CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE BROIL ELEMENT AND

STIRRER BLADE ASSEMBLY

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. To make servicing inside the oven easier, remove the microwave oven door (see Page 42 for the procedure).

3. Remove the oven racks.

4. To remove the broil element: a) Remove the two front and six rear

screws from the broil element.

2 Front Screws

b) Carefully pull the broil element for-

ward so that the terminals and wires slide through the holes in the liner. NOTE: Be careful not to pull the element too hard so that you disconnect the wires from the terminals. If this happens, you may have to remove the rear panel from the oven to r etrieve the wiring.

Broil Element Leads

5. To remove the stirrer blade assembly:

a) If not already done, remove the broil

element (refer to Step 4).

6 Rear Screws

CAUTION: When you remove the stirrer glass in the next step, be careful that it does not fall and break when the bracket is removed.

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CM Oven Service ManualLit. No. 94-30-006B

b) Remove the two screws from the stir-

rer glass bracket, and remove the bracket and glass.

Stirrer Glass Bracket & Screws

Stirrer Glass

c) Using one of the mounting screw ac-

cess holes in the stirrer blade, remove the eight screws from the stirrer blade assembly and remove the assembly.

Stirrer Blade Screws

Stirrer Blade Screw Access Hole

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CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE WAVEGUIDE

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. To make servicing inside the oven easier, remove the microwave oven door (see Page 42 for the procedure).

3. Remove the oven racks.

4. If not already done, remove the broil element, (refer to Step 4 on Page 30), and the stirrer blade assembly, (refer to Step 5 on Page 30).

5. Remove the two screws from the waveguide insulator and remove the insulator.

6. Remove the waveguide screws (#14-91-

142).

Waveguide Screws (1 of 14)

7. Refer to Page 22 and remove the magnetron, as instructed.

8. Remove the high voltage capacitor bracket, and lay the capacitor on top of the microwave transformer so you can access the screw underneath it.

9. Remove the six screws (3 on each side) from the stirrer motor platform.

Stirrer Motor HV Capacitor

Waveguide Insulator Screws

Waveguide

Insulator

Stirrer Motor Platform Screws ( 3 On Each Side)

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CM Oven Service ManualLit. No. 94-30-006B

10. Lift the back of the stirrer motor platform just high enough to remove the waveguide from underneath it.

Raise Stirrer Motor Platform Lift Waveguide

11. Clear any insulation away from the area that the waveguide will be mounted in so that the screw holes will align properly when the waveguide is installed.

Clear Insulation From This Area

Tech T ip!!

IMPORTANT: Make sure that you r einstall

the magnetron as instructed on Page 23.

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CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE CONVECTION ELEMENT &

CONVECTION MOTOR

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. To make servicing inside the oven easier, remove the microwave oven door (see Page 42 for the procedure).

Service

Alert!!

After reinstalling the oven door, check around the door for microwave radiation leakage.

5. To remove the convection element:

a) Remove the eight screws fr om the con-

vection element.

8 Screws Convection Element

b) Pull the element forward until the ter-

minal wires are inside the oven (the element terminals and wires are angled up 90˚). Disconnect the two wires from the terminals and remove the element.

Convection Element Wires

3. Remove the oven racks and supports.

4. Remove the four screws and two top insulator (mica) washers from the convection baffle and remove the baffle.

Baffle Screws With Insulator Washers

Screw Convection Baffle Screw

NOTE: It will be necessary to pull the oven out of the cabinet to replace the convection motor.

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Page 37

6. To remove the convection motor:

a) Remove the nut from the convection

fan blade and remove the blade and flat washer from the motor shaft.

Nut Convection Fan Blade

CM Oven Service ManualLit. No. 94-30-006B

Rear Shield Cover

Plate

Screw (1 of 15)

c) Remove the 15 motor mounting screws

from the rear shield cover plate and remove the plate.

b) CAUTION: The rear shield cover plate

is sealed and tested for microwave emissions at the factory. DO NOT RE-

MOVE THIS SHIELD COVER.

Rear Shield Cover Plate Screw (1 of 32)

Rear Shield Cover Plate

d) Motor and bracket assembly can now

be removed from the back of the oven.

Spacer (1 of 4) Bottom Motor Mtg. Screw

Continued on the next page.

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CM Oven Service Manual Lit. No. 94-30-006B

e) Remove the insulation from the motor

and convection motor bracket.

Insulation

Tech T ip!!

f) Remove the three screws from the con-

vection motor bracket and remove the bracket from the motor.

Top Screw

Convection Motor Bracket

Top Screw

1. After the fan blade is reassembled, spin the blade to assure that there is no inter ference with the wires in the rear.

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CM Oven Service ManualLit. No. 94-30-006B

REMOVING THE MEAT PROBE JACK

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. Pull the oven out of its mounting location just far enough so that you can access the meat probe jack access panel on the right side of the oven.

3. Open the microwave oven door.

4. Raise the cover on the meat probe jack, then use a 17 mm (11/16˝) socket, and r emove the hex nut.

6. Remove the piece of insulation that is covering the meat probe jack.

7. Pull the meat probe jack and flat washer out of the cutout and disconnect the two wires from the terminals.

Ground (–) Wire

Meat Probe Jack

Positive (+) Wire

5. Remove the screw from the meat probe jack access panel on the right side of the oven.

Screw

Meat Probe Jack Access Panel

Tech T ips!!

1. Connect the wire with the GND tag on it to the ground terminal on the meat probe jack. This terminal is part of the jack’s frame. Be sure to reinstall the flat washer on the jack.

2. To make it easier when reinstalling the hex nut on the jack, place the nut inside the spring cover and close the cover. Thread the nut onto the jack as far as possible by turning the cover, and then tighten it firmly using the socket.

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CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE HIDDEN BAKE ELEMENT

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. Pull the oven out of its mounting location so that you can access the trim and plenum covers.

3. Remove the trim and top plenum covers from the oven (see Page 10).

4. Remove the back cover from the oven.

5. Remove the wire wraps from the vertical support holes and wrap them around the wire bundles at the same four locations. This will allow you to keep the ties around the same wires when you reinstall the support later.

Wire Wrap (4 Places)

Vertical Support

Back Cover

Screw (1 of 25)

6 . Remove the eight screws (cir cled) from the

vertical support and remove the support from the back of the oven.

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CM Oven Service ManualLit. No. 94-30-006B

7. Remove the four bracket screws from the lower crossflow blower assembly and remove the assembly from the oven.

8. Disconnect the two motor wires (BU-74 & WH-75) and remove them from the wir e wrap.

Motor Connectors

Crossflow Blower

Assembly

Screws (2 of 4)

12. Bend the flange covering the hidden bake element down as necessary to remove the element.

Bend Flange Down To Access Bake Element

13. Disconnect the two orange wires (22 & 29) from the bake element terminals.

14. Remove the four screws from the mounting and element brackets (2 each).

Mounting Bracket Element Bracket

9. Remove the nine screws from the blower mounting plate.

Plastic Grommet Screw (1 of 9)

Blower Mounting Plate

10. Remove the plastic grommet from the blower mounting plate hole and remove the grommet from the wiring.

11. Bend the blower mounting plate down 90˚ along the perforated edge.

Mtg. Bracket Element Bracket Screw (1 of 2) Screws

15. Position the wiring to the side and pull the bake element and mounting bracket out of the oven.

Pull Bake Element &

Bracket Out

Wiring

Bend Plate Down 90˚

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CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE OVEN THERMAL SENSOR

WARNING

Turn off the electrical power going to the oven before servicing.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. T urn of f the electrical power going to the oven.

2. Open the microwave oven door.

3. Remove the oven racks.

4. Remove the two screws from the oven thermal sensor.

5. Pull the oven thermal sensor forward until the wire splices are inside the oven.

Cut Wires Here

Wire Splices

Thermal Sensor Screws

Oven Thermal Sensor

6. Using the instructions in the “Thermal Sensor Kit,” (#35-00-306), splice the wires from the new oven thermal sensor to the main wires. Cut the wires from the old sensor at the location shown above.

Page 40

Page 43

REMOVING THE UPPER (OR SINGLE)

OVEN DOOR GASKET

1. Fully open the oven door.

2. Pull the ends of the oven door gasket out of the hole in the door liner.

3. Unclip the gasket from the door liner and remove it.

Pull Clips Out

Of Holes In Liner

Pull Ends Out

Of Hole In Liner

CM Oven Service ManualLit. No. 94-30-006B

Upper (or Single)

Oven Door Gasket

Tech T ip!!

Use a small screwdriver to insert the ends of the gasket into the liner hole. Fully insert one end at a time

Service

Alert!!

Check around the door for microwave radiation leakage.

Page 41

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CM Oven Service Manual Lit. No. 94-30-006B

REMOVING AND REINSTALLING

THE MICROWAVE OVEN DOOR

REMOVING THE OVEN DOOR

CAUTION: Be careful handling the oven door when removing it, as it is very heavy. Never lift the door by the handle.

1. Pull the oven out of its mounting location so that you can access the left and right hinge pocket covers (see the following photo).

2. Remove the screws from the left and right hinge pocket covers and remove the covers.

Hinge Pocket Cover

4. Fully open the oven door.

5. Raise the U-clip over the hook on each of the hinges to lock them. This will prevent the hinge from snapping closed when the door is removed.

Hook

3. Remove the locking screw from each of the hinges.

Locking Screw

Raise U-Clip Over Hook

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CM Oven Service ManualLit. No. 94-30-006B

6. Grasp the oven door by the sides near the top, and carefully close it until the hook in the hinge contacts the hinge support (approximately 3/4 of the way). You will feel some spring resistance while you do this, which is normal.

REINSTALLING THE OVEN DOOR

1. Hold the oven door by the sides approximately 2/3 of the way down and insert the hinges into the oven slots near the top as far as possible.

7. Gently lean against the top of the door to hold it in position, and grasp the door firmly by the sides approximately 2/3 of the way down, then open the door slightly, and lift it until the hinges are free of the frame supports. Pull the hinges out of the oven slots and remove the door.

Insert Hinge Into Slot Near Top

Continued on the next page.

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CM Oven Service Manual Lit. No. 94-30-006B

2. Lower the oven door to its fully open position.

3. Rotate the U-clips on the hinges forward to the unlocked position.

Rotate U-Clip

Forward To Unlock

Make sure that the door seal is tight against the front of the oven liner and that the door is not crooked. If it is, push the hinges into the slots firmly until it is.

Tech T ip!!

Service

Alert!!

4. Close the oven door.

5. Reinstall the two hinge locking screws.

Locking Screw

6. Reinstall the hinge pocket covers.

After reinstalling the oven door, check around the door for microwave radiation leakage.

Page 44

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CM Oven Service ManualLit. No. 94-30-006B

REMOVING THE UPPER (OR SINGLE) OVEN DOOR

HANDLE & OUTER GLASS ASSEMBLY

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. Remove the upper (or single) oven door from the unit (see Page 42) and lay it on a padded surface with the glass side down and the bottom edge facing you.

2. Remove the two bottom edge screws and the two top screws from the liner . This will separate the glass and liner sections of the door .

Top Screws

Door Liner

5. To remove the outer oven door glass:

a) Remove the four screws from the left

and right glass support brackets and remove the brackets.

Top Screws

Glass Support

Brackets

Bottom Screws

b) Rotate the top door trim w/end caps

back and remove it from the top of the door .

Door Trim With End Caps

Bottom Screws

3. Lift the door liner assembly off the door glass assembly and set the liner aside.

4. T o remove the oven door handle, r emove the hex-head screws (see the small inset) from the left and right handle brackets and remove the brackets and handle from the glass.

Handle Brackets

6. If not already done, remove the handle from the outer door glass (see Step 4).

Service

Alert!!

After reinstalling the oven door, check around the door for microwave radiation leakage.

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CM Oven Service Manual Lit. No. 94-30-006B

REMOVING AN OVEN DOOR HINGE, ACTUATOR ARM,

CENTER GLASS, RF SCREEN, & INNER GLASS

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. Remove the upper (or single) oven door from the unit (see Page 42) and lay it on a padded surface with the glass side down and the bottom edge facing you.

2. Remove the two bottom edge screws and the two top screws from the liner . This will separate the glass and liner sections of the door (see Page 47).

3. Lift the door liner assembly off the door glass assembly and lay it liner-side-down on the padded work surface. NOTE: Set the oven door glass assembly out of the way so it does not get damaged.

4. To remove an oven door hinge:

5. To remove the actuator arm:

a) Remove the four screws from the baf fle

and remove the baffle.

b) Remove the four screws from the ac-

tuator arm bracket and remove the actuator arm from the liner.

Actuator Arm Bracket

Screw (1 of 4)

Top Screws

Baffle

a) Remove the mounting screw at the bot-

tom edge of the door.

b) Slide a piece of pipe over the end of

the hinge and push it against the spring until you can unlock the U-clip, then allow the hinge to return to its unlocked position, and remove the pipe.

c) Unhook the hinge at the top, and re-

move the hinge.

Unhook Hinge

Hinge Screw

Bottom Screws

6. To remove the center glass:

a) Remove the four screws fr om the insu-

lation cover and remove the cover.

Top Screws

Center Glass

Insulation

Cover

Bottom Screws

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CM Oven Service ManualLit. No. 94-30-006B

b) Remove the insulation strip from

around the center glass assembly.

Center Glass Assembly

Insulation Strip

c) Remove the screws from the four insu-

lation cover brackets and the four glass assembly clamps and remove the brackets and clamps.

2 Clamps

4 Brackets

2 Clamps

7. To remove the RF screen and the inner glass:

a) Remove the bottom insulation from the

door .

b) Remove the forty-eight screws from the

screen and remove the screen fr om over the inner glass . REASSEMBLY NOTE: Make sure that you position the screen with the best side showing through the inner glass.

RF Screen

Insulation

c) Lift the inner glass off the oven door.

CAUTION: The inner glass is not heattreated like the center glass. Be sure to

install the untreated glass in the inner glass position.

d) Lift the center glass and frame out of

the liner. CAUTION: The center glass is heat-treated on both sides. If you remove both the center and inner glass,

be sure to install the heat-treated glass in the center glass position.

Inner Glass

Insulation (Rope)

d) If you need to replace the insulation

“rope” that is under the inner glass, pull it out of the track and install the new one in its place. REASSEMBLY NOTE: Make sure that the end strands of the insulation do not show through the inner glass when you reinstall the glass.

Continued on the next page.

Page 47

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CM Oven Service Manual Lit. No. 94-30-006B

Service

Tech T ip!!

Alert!!

The center glass is heat-treated and has the

After reinstalling the oven door, check around the door for microwave radiation leakage.

letters “HB” stamped in two places near one of the edges.

If you are in doubt as to which glass is heattreated, use an ohmmeter to check it. To do this, set the ohmmeter to the R X 1 scale and touch the test probes to the glass. If the glass is heat-treated, the meter will indicate a short (0 Ω). If the meter does not indicate a reading (infinity), the glass is untreated.

Page 48

Page 51

TROUBLESHOOTING

TESTING THE COMPONENTS

Resistance Measurements

WARNING

TO AVOID ELECTRICAL SHOCK DISCONNECT THE

POWER TO THE APPLIANCE BEFORE TESTING.

CM Oven Service ManualLit. No. 94-30-006B

20A TIME-DELAY FUSE

Touch Metal Caps

Refer to Page 12 to access the 20A time-delay fuse. To test the 20A time-delay fuse, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

3. Touch the test leads to the metal end caps of the fuse. If the fuse is good, the meter should indicate a short circuit (0 Ω). If the fuse is open, the meter will indicate an open circuit (infinite resistance).

20A Time Delay Fuse

TRANSFORMER COOLING FAN MOTOR

Fan Terminals

Refer to Page 15 to access the transformer cooling fan. To test the motor, perform the following steps.

1. Turn off the electrical power to the oven.

2. Disconnect one of the wires from the fan motor.

3. Set the ohmmeter to the R x 1 scale.

4. Touch the test leads to the motor terminals. The meter should indicate between 135 Ω and 150 Ω.

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LIGHT TRANSFORMER

Secondary

Terminals

Primary T erminals

Refer to Page 13 to access the light transformer. To test the light transformer, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

3. Disconnect one of the wires from the bottom (primary) terminals.

4. Touch the test leads to the bottom terminals. The meter should indicate less than 1 Ω.

5. Disconnect the wires from the top three terminals.

6. Touch the test leads to the following numbered terminals. The meter should indicate less than 1 Ω at each location:

DOUBLE LINE BREAK RELAY

Switch (N.O.)

Solenoid

Refer to Page 13 to access the double line break relay. To test the double line break relay, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

3. Disconnect the two yellow (solenoid) wires from the relay.

4. Touch the test leads to the relay terminals. The meter should indicate less than 1 Ω.

5. Disconnect the other two (switch) wires from the relay.

6. Touch the test leads to the relay terminals. The meter should indicate an open circuit (infinite resistance).

a)Terminals 8 and 6 b)Terminals 8 & 10. c) Terminals 6 and 10.

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STIRRER MOTOR

Connectors

Refer to Page 14 to access the stirrer motor. To test the stirrer motor, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

3. Disconnect the stirrer motor wire going to the terminal block.

4. Touch the test leads to the motor connectors. The meter should indicate approximately 1.5 Ω.

HIGH VOLTAGE DIODE

Cathode (–)

Anode (+)

Diode Symbol

CAUTION: DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TESTING THE DIODE. REFER TO PAGE 18 FOR THE PROCEDURE.

Refer to Page 19 to access the high voltage diode. To test the high voltage diode, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

3. Disconnect the wires from the diode. IMPORTANT: Use the above photo for the

proper terminal polarity connections. Disregard any other polarity markings on the diode body.

4. Touch the negative (–) meter lead to the cathode terminal and the positive (+) lead to the anode terminal. The meter should indicate continuity (current flow).

5. Switch the test leads and the meter should indicate a very high resistance.

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HIGH VOLTAGE CAPACITOR

Terminals

CAUTION: DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TESTING IT. REFER TO PAGE 18 FOR THE PROCEDURE.

Refer to Page 18 to access the high voltage capacitor. To test the high voltage capacitor, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 10K scale.

3. Disconnect the wires from the capacitor terminals.

HIGH VOLTAGE TRANSFORMER

Tan Lead (secondary)

Orange Leads

(secondary)

CAUTION: DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TESTING THE TRANSFORMER. REFER TO PAGE 18 FOR THE PROCEDURE.

Refer to Page 19 to access the high voltage transformer. To test the high voltage transformer, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

Primary Terminals

4. Touch the test leads to the capacitor terminals. The meter should indicate a high resistance, and then gradually begin to fall back toward infinity.

5. Switch the test leads and the meter should again indicate a high resistance, and gradually fall back toward infinity.

Testing The Primary Winding

3. Disconnect the black and white wires from the primary terminals of the transformer.

4. Touch the test leads to the primary terminals. The meter should indicate less than 1 Ω.

Testing The Secondary Windings

5. Disconnect the two orange transformer wires from the magnetron terminals.

6. Touch the test leads to the orange wire connectors. The meter should indicate less than 1 Ω.

7. Disconnect the light tan transformer wire from the high voltage capacitor.

8. Touch one of the test leads to the chassis and the other lead to the tan wire connector. The meter should indicate less than 1 Ω.

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MAGNETRON

Filament Terminals

CAUTION: DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TESTING THE MAGNETRON. REFER TO PAGE 18 FOR THE PROCEDURE.

Refer to Page 22 to access the magnetron. To test the magnetron, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

3. Disconnect the leads from the filament terminals of the magnetron.

4. Touch the test leads to the primary terminals. The meter should indicate less than 1 Ω.

MAGNETRON THERMAL CUTOUT (TCO)

Reset Button

Terminals

CAUTION: DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TESTING THE MAGNETRON THERMAL CUTOUT. REFER TO PAGE 18 FOR THE PROCEDURE.

Refer to Page 27 to access the magnetron thermal cutout (TCO). To test the TCO, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

3. Disconnect one of the leads from the magnetron TCO terminals.

4. Touch the test leads to the normally-closed terminals. The meter should indicate a short circuit (0 Ω). NOTE: If the meter indicates an open circuit, (infinite resistance), press the reset button on the TCO and check it again. If it remains open, replace the TCO.

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MAGNETRON FAN MOTOR

Ter minals

Refer to Page 16 to access the magnetron fan motor. To test the motor, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

3. Disconnect one of the leads from the magnetron fan motor terminals.

4. Touch the test leads to the motor terminals. The meter should indicate less than 1 Ω.

CROSSFLOW BLOWER MOTOR

Ter minals

Refer to Page 17 to access the crossflow blower. To test the motor, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

3. Disconnect one of the leads from the crossflow blower motor terminals.

4. Touch the test leads to the motor terminals. The meter should indicate less than 1 Ω.

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DOOR LATCH ASSEMBLY

Latch Interlock Switch

Latch Motor

Terminals

Door Unlock Switch

(N.O.) Terminals

Refer to Page 26 to access the door latch assembly. To test the door latch assembly components, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

Testing The Latch Motor

(N.O.) Terminals

Door Lock

Switch (N.O.)

Ter minals

MONITOR & SECONDARY SWITCHES

Monitor Switch

Secondary Switch (N.O.) Terminals

Refer to Page 27 to access the monitor and secondary switches. To test the switches, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

Testing The Secondary Switch (NormallyOpen N.O.)

(N.C.) Terminals

3. Disconnect the two orange wires from the latch motor terminals.

4. Touch the test leads to the motor terminals. The meter should indicate less than 1 Ω.

Testing The Door Lock, Door Unlock, & Latch Interlock Switches (All NormallyOpen N.O.)

5. Disconnect one of the wires from the terminal of the switch under test.

6. Touch the test leads to the switch terminals. The meter should indicate an open circuit (infinite resistance).

7. Press the switch button to close the contacts. The meter should indicate a short circuit (0 Ω).

3. Disconnect one of the wires from the secondary switch.

4. Touch the test leads to the switch terminals. The meter should indicate an open circuit (infinite resistance).

5. Press the switch button to close the contacts. The meter should indicate a short circuit (0 Ω).

Testing The Monitor Switch (NormallyClosed N.C.)

6. Disconnect one of the wires from the monitor switch.

7. Touch the test leads to the switch terminals. The meter should indicate a short circuit (0 Ω).

8. Press the switch button to close the contacts. The meter should indicate an open circuit (infinite resistance).

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DOOR SWITCH

Terminals (N.O.)

Refer to Page 25 to access the door switch. To test the switch, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

3. Disconnect one of the wires from the door switch.

4. Touch the test leads to the normally-open switch terminals. The meter should indicate an open circuit (infinite resistance).

5. Press the switch button to close the contacts. The meter should indicate a short circuit (0 Ω).

OVEN THERMAL SENSOR

Refer to Page 40 to access the oven thermal sensor. To test the sensor, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

3. Touch the test leads to the in-line splice connections inside the oven with the sensor removed, or at connector P3 on the electronic oven control board. The meter should indicate approximately 1050 Ω at room temperature.

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BROIL ELEMENT

Terminals

Refer to Page 30 to access the broil element. To test the element, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

3. Disconnect one of the wires from the broil element.

4. Touch the test leads to the broil element terminals. The meter should indicate between 13 Ω and 20 Ω.

BAKE ELEMENT

Terminals

Refer to Page 38 to access the bake element. To test the element, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

3. Disconnect one of the wires from the bake element.

4. Touch the test leads to the bake element terminals. The meter should indicate between 20 Ω and 30 Ω.

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CONVECTION ELEMENT

Terminals

Refer to Page 34 to access the convection element. To test the element, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

3. Disconnect one of the wires from the convection element.

CONVECTION MOTOR

Terminals

Refer to Page 36 to access the convection motor. To test the motor, perform the following steps.

1. Turn off the electrical power to the oven.

2. Set the ohmmeter to the R x 1 scale.

3. Disconnect one of the wires from the convection motor.

4. Touch the test leads to the convection element terminals. The meter should indicate between 15 Ω and 25 Ω.

4. Touch the test leads to the convection motor terminals. The meter should indicate between 10 Ω and 20 Ω.

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M/W TRANSFORMER AIR SWITCH

M/W Transformer Air

Switch (N.O.) Ter minals

Refer to Page 15 to access the M/W transformer air switch. To test the switch, perform the following steps.

1. Turn off the electrical power to the oven.

2. Disconnect one of the wires from the M/W transformer air switch.

3. Set the ohmmeter to the R x 1 scale.

4. Touch the test leads to the switch terminals. The meter should indicate an open circuit (infinite resistance).

5. Actuate the M/W transformer air switch by moving the air paddle. The meter should indicate a short circuit (0 Ω).

MEAT PROBE JACK

Terminals

Refer to Page 37 to access the meat probe jack. To test the jack, perform the following steps.

1. Set the ohmmeter to the R x 1 scale.

2. Disconnect one of the wires from the meat probe jack.

3. Touch the test leads to the meat probe jack terminals. The meter should indicate an open circuit (infinite resistance).

4. Plug the meat probe into the jack. The meter should indicate a short circuit (0 Ω).

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MICROWAVE PCB CONTROL

Refer to Page 12 to access the microwave PCB control. The control has a relay (K1), two headers (P1 & P3), and two 1/4˝ wire terminals (P2-1 & P2-2). These components perform the following functions:

Relay K1: Transfers 120-volts AC to the highvoltage transformer to activate the microwave circuitry. K1 is activated by 24-volts DC from the relay board.

Header P1: Receives 24-volts and 5-volts DC from the relay board using wire harness connector P6. The 18-volts DC activates the relay coil, and the 6-volts DC activates the triac on the Microwave PCB Control.

Terminal P2-1: Inputs 120-volts AC from the latch interlock switches.

Terminal P2-2: Outputs 120-volts AC to the high-voltage transformer when relay K1 closes.

Header P3: Receives 12-volts AC from the halogen light transformer at pins 1 & 2, and Pins 3 & 4 output 12-volts DC to activate the upper (or single) oven latch motor. The 12volts DC is produced by passing the 12-volts AC through a bridge rectifier (see the following circuits).

Positive AC Cycle

(+)

12 Volts AC

12 Volts

Pulsating DC

(–)

Negative AC Cycle

(–)

Header P1

12 Volts AC

12 Volts

Pulsating DC

(+)

Relay K1 Terminal P2-2

Terminal P2-1

Bridge Rectifier Diodes

Header P3

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MICROWAVE COMPONENTS DESPCRIPTION

Switches

Fuse

Diode (High Voltage)

Capacitor (High Voltage)

Transformer (High Voltage)

Magnetron Tube

Microwave PCB Control

7 8

Stirrer Motor

Microwave Cooling Fan

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The interlock switches

The CM Oven has a total of 3 safety switches. The primary switch is mounted on the upper oven latch (latch interlock switch). The other two switches are mounted in the upper plenum behind and below the control panel. These switches are the monitor and secondary switch. These switches are designed to prevent the microwave oven from operating if the door does not close pr operly or the primary switches fails. These switches are not adjustable. They must be replaced if they fail.

Latch mounted switch;

The primary latch interlock switch is mounted on the microwave oven door latch assembly. When microwave is selected, the latch assembly motor latches the door closed. The latch lock switch which is “normally open” closes to signal the relay board that the door is latched. The latch interlock switch which is also normally open closes and completes the circuit to the microwave board.

*The latch hook will not close the switches unless the microwave oven door is closed when the motorized latch is operated.

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Oven Mounted Switches

The secondary and the monitor switches are mounted on a bracket. The bracket is located on the plenum behind the control panel on the right side of the oven (see Front View, below).

Front View

N.C.

➝

Top View

The monitor switch is mounted on the left side of the bracket. It is normally closed. The switch is opened by the forward motion of the hook (See Figure A) when the door is closed. The purpose of this switch is to cause the fuse to blow if the latch switch is not open when the microwave door is opened. The switch is wired across the neutral and positive side of the line. The fuse will blow if the monitor switch and the primary switch are closed at the same time.

Monitor Switch

Secondary

➝

COM

N.O.

The right side door interlock switch (secondary) is mounted on the right side of the oven bracket. It is normally open. The switch is closed by side ways motion of the hook (See Figure A) when the oven door is closed. This switch provides a current path to the microwave plate transformer. With the door open or if the switch fails, there is no current to the microwave transformer . The oven mounted switches are mounted as shown in the illustration above, facing the oven (See Top View, above)

Switch

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Switches Activated by Hook

The switches are activated by a spring action hook on the microwave oven door. When the door is closed, the hook contacts and activates the switches (see illustration, below).

➝

Switches

Door Hook

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20 AMPERE FUSE

The Microwave Oven is protected fr om interlock switch failure by a 20 amper e Fuse. A defective switch or any other factor causing an overload on the microwave circuit will blow the fuse and stop the operation of the microwave section of the oven. The fuse is located in a fuse holder in the upper plenum.

Microwave Fuse Failure:

The purpose of the fuse system is to prevent operation of the unit in the event of a safety switch failure. The safety switches prevent the unit fr om emitting microwave energy if the door is not completely closed. The following is an explanation of the safety switches and an explanation of the fuse protection system. The safety switches are the monitor switch and the latch interlock switch (primary switch), and the right side door interlock switch (secondary switch).

The latch interlock switch (primary switch) is mounted on the latch assembly. The latch interlock switch is closed by the latching of the motorized oven door latch.

The monitor switch and the right side door interlock switch (secondary switch) are activated by the door strike movement.

Fuse Failure Modes:

The fuse can open due to any of the following failure modes:

1) A short in the microwave cir cuit or a component failure that causes the micr owave circuit to draw more than 20 amps.

2) The monitor switch is closed when the latch’s interlock switch is also closed.

DO NOT ATTEMPT TO REP AIR A SAFETY SWITCH.

REPLACE A FAILED SAFETY SWITCH.

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DIODE

The diode is a device used to convert alternating current (AC) into pulsating direct current (DC) allowing it to pass forward in one direction while blocking the current flow in the opposite direction. There is no charge stored in this part.

HIGH VOLTAGE TRANSFORMER

The high voltage transformer has one primary winding and two secondary windings. The “stepup” secondary winding converts 120 volts AC. To 2300 volts across the transformer terminals.

The other secondary winding “steps down” 120 volts AC to 3.3 volts AC. Which heats the magnetron tubes cathode filament. The cathode filament preheats approximately 1 second before the high voltage circuit is energized.

MAGNETRON TUBE

The magnetron tube is a vacuum tube in which the flow of electrons from the heated cathode to the anode is controlled by a magnetic field to produce an electromagnetic wave (2450 mhz). These electromagnetic waves are called “microwaves.”

To operate the magnetron tube requires both a minimum power input of 3800 to 4000 volts DC. From the transformer. Diode, and capacitor, and 3.8 volts from the filament transformer lead. The tube has a 650 watt rating.

Note

Wir e mesh gasket (rf) between the magnetron tube and the wave guide must be in place when reinstalling the tube. When reinstalling the tube, tighten the four tube nuts diagonally. Do not tighten the two nuts on one side, then the two nuts on the other side. (Removing and replacing the magnetron tube requires a microwave leakage test.)

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MICROWAVE BOARD

The Microwave Board has one snap relay (K1).; Two Pin Headers (P1 and P3) and two 1/4” terminals (P2-1 and P2-2).

K1 Relay:

This relay transfers 120 Volts AC to the high voltage transformer to activate the microwave circuit. The K1 Relay Coil is activated by 24 Volts DC from the relay board.

P1 Pin Header

This is a 3-pin header that receives 24 Volt DC from the Relay Board using a wire harness from PIN Header P6 on the relay board.

P3 Pin Header

Pins 1 and 2 inputs 12 Volts AC fr om the halogen light transformer circuit. Pins 3 and 4 output 12 volts DC (Rectified through a series of diodes) to activate the upper oven (or single oven) latch motor.

P2-1 Terminal:

This terminal inputs 120 Volts AC from the latch interlock switches.

P2-2 Terminal:

This terminal outputs 120 Volts AC to the transformer when relay K1 closes.

STIRRER MOTOR

The stirrer motor is a 120 volt AC motor. The purpose of the stirrer motor is to run the stirrer blades at the output of the wave guide. The stirrer rotates at about 60 rpm.

As the microwave energy enters the oven cavity through the wave guide, it bounces of f the rotating stirrer blades and is reflected throughout the oven cavity at constantly changing angles, providing a more even microwave distribution.

In the jet impinged oven, the stirrer blade also mixes the air flow into the top of the

oven.

COM

Air Switch

Microwave Transformer Cooling Fan and Air Switch

The Microwave Transformer Cooling Fan is a box fan mounted between the control panel and the high voltage transformer. There is an air switch (see illustration, above) with a paddle mounted on the fan bracket. The fan blows air across the high voltage transformer to keep the transformer cool. The air flow from the fan moves the paddle on the air switch. The paddle movement closes the normally open contacts on the air switch. The air switch is in series with the air switch located on the base area below the lower oven. If this air switch does not close, you will see an F34 error code in the control panel.

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“CM” Lower Oven

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“CM” RELAY BOARD MATRIX

REPLAY FUNCTION

K0 Upper Oven Latch Motor K1 Lower Oven Latch Motor K2 None K3 None K4 Upper Oven Cooling Motor K5 Lower Oven Cooling Motor K6 Upper Oven Halogen Lamp K7 Lower Oven Halogen Lamp K8 Upper Oven Bake Element K9 Upper Oven Broil Element K10 Upper Oven Convection Element K11 Upper Oven Convection Motor K12 Lower Oven Bake Element K13 Lower Oven Broil Element K14 Lower Oven Convection Element K15 Lower Oven Convection Motor

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“CM” DAC RELAY BOARD

(Digital Appliance Controls)

There are 2 relay boards, 1 for a single oven and 1 for a double oven. You can use the double oven board for a single oven. You must use a double oven board for a double oven.

The relay board has 14 snap relays activated by 24 volts d.c., 8 small pin headers that carry signal voltage to components, and 5 large pin headers that provide or transfer 120 volts ac to components.

Relays K0 through K15:

K0 Transfers 12 volts from transformer to microwave board. K1 Transfers 120 volts from L2 to lower oven latch motor. K2 Transfers 120 volts from L2 to microwave stirrer motor. K3 None K4 Transfers 120volts from L2to both oven cooling motors, tube fan, m/w TX

and cooling fan.

K5 Transfers 120 volts from L2 to both oven cooling motors, tube fan, m/w TX

and cooling fan. K6 Transfers current to complete L2 v.a.c. Upper oven halogen light circuit. K7 Transfers current to complete L2 v.a.c. Lower oven halogen light circuit. K8 Transfers 120 volts from L2 to upper oven bake element. K9 Transfers 120 volts from L2 to upper oven broil element. K10 Transfers 120 volts from L2 to upper oven convection element. K11 Transfers 120 volts from L2 to upper oven convection motor. K12 Transfers 120 volts from L2 to lower oven bake element K13 Transfers 120 volts from L2 to lower oven broil element. K14 Transfers 120 volts from L2 to lower oven convection element. K15 Transfers 120 volts from L2 to lower oven convection motor.

These relays have normally open contacts that transfer voltage when the are snapped closed. These relays have a coil that is snapped closed by 24 VDC from the eeprom (memory chip) on the relay board.

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DAC RELAY BOARD

(continued)

The relay board has 8 small pin headers. They are identified as P2, P3, P5, P6, P9, P10, P11, P14, P15. These small pin headers carry signal voltage to specific components. The pin numbers are identified on the schematic. The illustration below shows that the arrow will always point to Pin#1.

➛

8 Small Pin Header Identification:

P2 Sends current to the lower oven sensor. It is a 3 pin header

only #l and #2 are used. #3 is missing on the pin header and #3 is plugged on the harness so it cannot be miswired.

P3 Sends current to the upper oven sensor. It is a 3 pin header.

only #2 and #3 are used. #1 is missing on the pin header ano #l is plugged on the harness so it cannot be miswired.

P5 Sends current to the lower oven latch switches. It is a 5 pin

header. Only #1,2,3 and 5 are used. #4 is missing on the pin header and is plugged on the harness to prevent miswiring.

P6 Send 18 VDC to the Microwave board to snap K1 relay closed and 5 VDC to

the microwave board to activate the triac.

P9 Sends current to the upper oven latch switches. It is a 4 pin

header. All 4 pins are used.

P10 Sends current to p10 header on the display head. It is an 8 pin

header. All 8 pins are used.

P11 Sends current to Pl 1 header on the display head. It is a 9 pin

header. All 9 pins are used.

Pl4 Sends current to the upper oven double line break relay coil.

it is a 2 pin header. Both pins are used.

Pl5 Sends current to the lower oven double line break relay coil.

it is a 3 pin header. Only #l and #3 are used. #2 is missing on the pin header and is plugged on the harness to prevent miswiring.

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DAC RELAY BOARD

(continued)

The relay board has 5 large pin headers. They are identified as P0, P1, P7, P8, P18. These large pin headers carry current to specific components. The pin numberts are identified on the schematic.

P0 large pin header has 8 pins and are identified as follows;

P0-1 Receives current from center tap of light transformer. P0-2 Sends current to microwave board to activate m/w oven door latch. P0-3 Blank P0-4 Sends 120VAC to lower oven latch motor P0-5 Blank P0-6 Sends 120 VAC to microwave stirrer motor. P0-7 Not used P0-8 Blank

P1 large pin header has 8 pins and are identified as follows;

P1-1 Receives current from center tap of halogen light transformer. P1-2 Sends current to lower oven halogen lights. P1-3 Receives current from center tap of halogen light transformer. P1-4 Sends current to uper oven halogen lights. P1-5 Blank P1-6 Sends current to both cooling motors, tube fan and microwave transformer

cooling fan. P1-7 Blank P1-8 Sends current to both cooling motors, tube fan and microwave transformer

cooling fan.

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DAC RELAY BOARD

(continued)

P7 large pin header has 4 pins and are identified as follows;

P7-1 Blank P7-2 Blank P7-3 Current from L2 to K11 relay P7-4 Current to upper oven convection motor

P8 large pin header has 4 pins and are identified as follows;

P8-1 Current from L2 to K15 relay. P8-2 Current to lower oven convection motor. P8-3 Blank P8-4 Blank

P18 large pin header has 6 pins and are identified as follows;

P18-1 Current from L1 to relay board transformer. P18-2 Blank P18-3 Neutral from “n” to relay board transformer. P18-4 Not used P18-5 Blank P18-6 Chassis ground

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Explanation of the

W ire Harness

➛

Connector Housing

The wire harness is shown in the illustration above.

➛

Wires

The wire harness’ slide onto the pin headers of the relay board, display head, and touch control boards. The illustration above shows the pin headers on the relay board.

➞

PIN HeaderPIN Header

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W ire Harnesses

(Continued)

The “CM” oven uses 5 wire harnesses to transfer signal voltage between the DAC control (relay board), display head, and touch control boards (glued on the glass). The 5 wire harness’ connect to the corresponding pin headers on the corresponding components (relay board, display head, touch control board). These 5 wire harness’ are identified as follows:

2 Wire White Power Harness:

This wire harness has 2 wires and connects from pin header P8 on the display head to pin header P2 1 on the left touch control board. The center hole of the connector is plugged so it cannot be mis-wired. This harness sends 24 volts AC. To the touch control boards.

7 Wire White Bridge Harness:

This 7 wire harness connects from pin header P2 on the left side TCB to pin header P2 on the right side tcb. The #2 hole on the connector housing is plugged (there is no wire). This harness sends commands between the left tcb and the right tcb.

8 Wire Yellow Display Harness:

This 8 wire yellow harness connects from pin header P10 on the display head to pin header P10 on the relay board (right rear corner of relay board). This harness sends display signals from the relay board back to the display head.

9 Wire Orange Communication Harness:

This 9 wire harness connects from pin header P11 on the display head to pin header P11 on the relay board (right front comer of board). This harness sends communication signals from the display head to the relay board.

18 Pin White Communication Harness:

This split wire harness has 18 wires and connects from pin header P1 on the large left side tcb to pin header P1 on the display head. The side with the single connector goes to the display head; the side with the split (2) connector housings goes to the left side TCB. This harness sends communication from both the left and right TCBs to the display head.

Page 75

Page 78

CM Oven Service Manual Lit. No. 94-30-006B

Troubleshooting chart

for relay board header pin failures

Wir e harness off at pin header; or circuits open:

P2 Lower oven sensor:

Control functions normal. When sensor opens, f-61 code will

appear. If sensor shorts, f-60 will appear. Cooling fan is on

constantly.

P3 Upper oven sensor:

Controls function normal. When sensor opens, f-31 code will

appear. If sensor shorts, f-30 will appear. Cooling fan is on

constantly.

P5 Lower oven door latch:

Will accept all modes except self clean. When set in self clean,

“DOR” will flash and self clean will erase.

P9 Upper oven door latch:

Will accept all modes except self clean. When set in self clean,

“dor” will flash and self clean will erase

P10 Sends display signals to display head:

Glass control panel is completely dead. No display, circuit

Must be reset at breaker.

P11 Sends communication signals to display head:

Glass control panel is completely dead. No display, circuit

must be reset at breaker.

P0 Upper/lower door latch motors:

No fail code, will accept all modes except self clean. When

either oven is set to self clean, the display will be on constantly,

doors will not lock. It will not go into self clean.

Page 76

Page 79

P18 Relay board transformer:

No fail code, no display at all. Board is dead.

P1 Both cooling motors and halogen lights:

Will accept modes. In about 45 seconds F-34 will appear in the upper oven or F-64 will appear in the lower oven because the

Coolingmotors did not come on to close the air switches and signal the board. Additionally, the halogen lights in both ovens will not work. All relays will close but the lights and motors will not work.

P8 Lower oven convection motor:

CM Oven Service ManualLit. No. 94-30-006B

No fail code. The lower oven convection motor will not work. The relay will snap closed.

P7 Upper oven convection motor:

No fail code. The upper oven convection motor will not work. The relay will snap closed.

P14 Upper oven double line break relay coil:

No fail code. If double line break relay does not close, l1 (120 volts) will not reach upper oven bake, broil, convection elements.

P15 Lower oven double line break relay coil:

No fail code. If double line break relay does not close, l1 (120 volts) will not reach upper oven bake, broil, convection elements.

Page 77

Page 80

CM Oven Service Manual Lit. No. 94-30-006B

MICROWAVE PROBE CONVECTION BAKE UPPER

COOKSMART SELF CLEAN BROIL ROAST UPPER

1-2-3-4 OFF

PAUSE PROOF STOP COOK LOWER

RESUME DEHYDRATE TIME TIME OFF

LOWER

“CM” OVEN CONTROL PANEL

• Touch Control Glass

• Touch Control Boards

• Display Head

12 3

45 6

78 9

START 0

LIGHT PANEL LOCK CLOCK

TIMER 1 TIMER OFF TIMER 2

1 - BREAD, DESSERT

CS+ CS+2

LARGE ROAST/POULTRY

CS+3

SMALL ROAST/POULTRY

CS+4

VEGETABLES

Page 78

Page 81

CM Oven Service ManualLit. No. 94-30-006B

ELECTRONIC OVEN CONTROLS

HANDLING THE BOARDS

The Touch Control Board and the Display Head are subject to failure if static electricity is transferred to the components during handling. When handling these parts, use a grounding strap, if available. If not, touch any grounded metal surface, (e.g. the appliance chassis), prior to handling these components.

The replacement Touch Control Board and the Display Head are packaged in antistatic bags. When removing the boards from their bags, handle them as follows:

CAUTION

Power to Oven must be truned OFF before disconnecting or reconnecting wire harnesses to relay board, control panel or display board.

Touch Control Board

Handle the Touch Control Board only by the edges of the glass and the plastic frame. DO NOT TOUCH the connector pins, or the microprocessor chips.

Display Head

Handle the Display Head only by the edges of the plastic frame. DO NOT TOUCH the connector pins, the microprocessor chip, or jumper wires.

IMPORTANT NOTE: Repack the old boards in the antistatic bags and original packaging before returning them to a parts distributor.

Page 79

Page 82

CM Oven Service Manual Lit. No. 94-30-006B

Control Panel Assembly

The control panel assembly is comprised of the following parts; Control panel:

There are a total of 6 control panels. 2 black, 2 white and 2 stainless. The control panels are what determines the color of the unit.

Curved glass touch panel:

There are 2 glass touch panels. One is for the single oven, the other is for the double oven. Both are black in color and both are the same size. The difference between a 27-inch oven and a 30-inch oven is determined by the control panel.

Mounting brackets:

There are 6 mounting brackets that hold the glass against the control panel snug. 2 of these brackets mount the display head to the back plate.

Back plate:

The back plate is used to put pressure against the glass and hold it in place. The back plate also serves to mount the display head.

Wire harnesses:

There are a total of 5 wire harnesses on the control panel. There is 1 orange harness, 1 yellow harness, and 3 white harness’.

Display head:

There are 2 display heads; one for the single oven, one for the double oven.

Page 80

Page 83

CM Oven Service ManualLit. No. 94-30-006B

Glass touch panel

The glass touch panel is comprised of a piece of curved glass with 2 control boards glued onto it.

Left side touch control board:

The large touch control board is glued on the left side of the curved glass. The large touch control board controls the following 12 modes;

MICROWAVE PROBE CONVECTION BAKE UPPER

COOKSMART SELF CLEAN BROIL ROAST UPPER

1-2-3-4 OFF

PAUSE PROOF STOP COOK LOWER

RESUME DEHYDRATE TIME TIME OFF

LOWER

This control board has 3 pin headers and are identified as P1, P2, P3. P1 pin header has 21pins (only 20 are used, #2 is missing) and connects

to the display head using 3 harnesses. One harness has 10 wires, one harness has 8 wires and one harness to 2 wires.

P2 pin header has 8 pins (only 7 are used, #2 is missing) and connects to the small right side touch control board.

P3 pin header on the large left side touch control board is not used.

Right side touch control board:

The small touch control board is glued on the right side of the curved glass and controls the following 7 modes;

12 3

45 6

78 9

This control board has 1 pin header and is identified as P2.

P2 pin header has 8 pins (only 7 are used, #2 is missing), and connects to the large left side control board.

START 0

LIGHT PANEL LOCK CLOCK

TIMER 1 TIMER OFF TIMER 2

CS+

1 - BREAD, DESSERT

CS+2

LARGE ROAST/POULTRY

CS+3

SMALL ROAST/POULTRY

CS+4

VEGETABLES

Page 81

Page 84

CM Oven Service Manual Lit. No. 94-30-006B

Display Head

The display head has a total of 8 pin headers (0nly 7 are used), they are identified as P1, P2, P4, P6, P8, P10 and P11.

P1 pin header has 18 pins and connects to the large touch control board (P1).

P2 pin header has 2 pins and connects to the meat probe.

P4 pin header has 2 pins and connects to the lower oven air

switch.

P6 pin header has 2 pins and connects to the upper oven air switch and the microwave transformer air switch.

P8 pin header has 2 pins and connects to the large touch control board (P1).

P10 pin header has 8 pins and connects to the relay board (white harness to P10 on relay board).

P11 pin header has 9 pins and connects to the relay board ( white harness to P11 on relay board).

Page 82

Page 85

CM Oven Service ManualLit. No. 94-30-006B

Troubleshooting chart

for display head pin header failures

Wir e harness off at pin header or open circuits

P10 Accepts display signals from relay board:

Glass control panel is completely dead. No display, circuit must be reset.

P11 Accepts communication signals from relay board:

Glass control panel is completely dead. No display, circuit must be reset.

P2 Upper oven meat probe:

No probe display when probe is inserted. Wont accept program. If probe is shorted, the probe display will be on constantly and the unit will accept no programs at all.

P6 Upper oven air switch:

F-34 will appear if upper oven air switch does not close. If air switch does not close the mode is cancelled after about 45 seconds.

P4 Lower oven air switch:

F64 will appear if lower oven air switch does not close. If air switch does not close the mode is cancelled after about 45 seconds.

P8 Power supply to touch control board:

No fail code, time of day on clock, control panel is dead, no reaction.

P1 Display/communication signals to tcb:

No fail code. Time of day on clock, control panel is dead, no reaction.

Troubleshooting chart for right side touch

control board header pin failures

Wir e harness off at pin header or circuits open:

P2 Sends commands to display head:

No fail code. Will not send commands from right side of tcb to display head. Such as numbers 0 through 9 and “start."

Page 83

Page 86

CM Oven Service Manual Lit. No. 94-30-006B

CM LOWER OVEN

Bracket Screws

Broil Element

Brackets

BACK OF

LINER

Hidden Bake Element

Under Oven Liner

Broil Element

Cover

Hex Nut

2 Top Front Mounting

Screws

White Wires

Access

Panel

Meat Probe

Jack

Page 84

Page 87

CM Oven Service ManualLit. No. 94-30-006B

REMOVING THE HIDDEN BAKE ELEMENT

(LOWER OVENS ONLY)

WARNING

Turn off the electrical power circuit to the oven at the main junction box before servicing this unit.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. Turn off the electrical power to the oven.

2. Pull the oven out of its mounting location so that you can access the back.

3. Remove the screws from the rear panel and remove the panel (see Figure A, Page

86).

Refer to Figure B (Page 86) for the following steps.

4. Unwrap and remove the indicated wire tie from the support bracket.

5. Remove the three screws from the support bracket and rotate it to the right so you can access the flange at the bottom of the oven.

6. Remove the six screws from the flange.

7. Remove the two wires from the bake element.

8. Refer to Figure C (Page 86) and bend the bottom flange down as far as possible so that you can pull the bake element out from under the unit.

Refer to Figure D (Page 86) for the following steps.

9. Remove the screws from the hidden element cover and remove the cover.

10. Remove the two screws from the hidden bake element and pull the element out from the unit. NOTE: Be careful not to tear the insulation under the element.

Page 85

Page 88

CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE HIDDEN BAKE ELEMENT

(LOWER OVENS ONLY)

Support

Bracket

Remove Screws

Rear Panel

Bend Flange

Down

Remove Screws

FigureA

Flange

Bend Flange

Down

Bake Element

Wires

Flange

Remove 3 Screws

Wire Tie

Flange

Remove 6 Screws

Figure B

Figure C

Page 86

Screw

(1 of 2)

Screw

(1 of 4)

Figure D

Hidden

Bake Element

Hidden

Element Cover

Page 89

CM Oven Service ManualLit. No. 94-30-006B

REMOVING THE OVEN TEMPERATURE SENSOR

WARNING

Turn off the electrical power circuit to the oven at the main junction box before servicing this unit.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

Refer to illustration, below, for the following steps.

1. Turn off the electrical power to the oven.

2. T o make servicing easier , remove the oven door (see Page 99).

3. Remove the racks from the oven.

4. Remove the screws from the bracket and pull the oven temperature sensor forward until the wire connectors are through the opening.

5. Cut the inline splices from the oven temperature sensor and main harness wires.

6. Connect the wires from the new oven temperature sensor to the main harness wires with two red inline splices. After you connect the wires, pull on them to make sure that the inline splices are secure.

7. Use a screwdriver or stiff wire and push the wires into the back of the oven as far as they will go, then install the oven temperature sensor in the oven liner with its two screws.

8. Reassemble the oven.

Oven Liner

Inline Splices

Slide Fiber Sleeving Over Wires & Against Collar Of Oven Temperature Sensor

TECH TIP!!

Be sure the oven temperature sensor connectors are pushed back into the rear of the oven and out of the oven heat zone.

MOUNTING SCREW

Collar

OVEN TEMPERATURE SENSOR

Page 87

Page 90

CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE CONVECTION BAKE ELEMENT

WARNING

Turn off the electrical power circuit to the oven at the main junction box before servicing this unit.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

Refer to illustration, below, for the following steps.

1. Turn off the electrical power to the oven.

2. T o make servicing easier , remove the oven

door (see Page 99).

3. Remove the racks from the oven.

4. Remove the front screws fr om the left and right oven rack supports and remove the supports from the oven liner.

5. Remove the screws from the convection baffle and remove the baf fle from the back of the oven liner.

6. Remove the screws from the convection bake element bracket and the screw from the bottom support and pull the element forward, then disconnect the wires from the terminals.

7. Install the new convection bake element and connect the wires to the terminals.

8. Reassemble the oven.

BACK OF

LINER

Top

Screw

CONVECTION

ELEMENT

Support

Screw

Bottom Screws

Bracket Screws

Bottom Support

Bracket

CONVECTION FAN

ASSEMBLY NOT SHOWN

Top

Screw

Convection Baffle

Page 88

Page 91

CM Oven Service ManualLit. No. 94-30-006B

REMOVING A CONVECTION FAN MOTOR

WARNING

Turn off the electrical power circuit to the oven at the main junction box before servicing this unit.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

Refer to illustration for the following steps.

1. Turn off the electrical power to the oven.

2. T o make servicing easier , remove the oven door (see Page 99).

3. Remove the racks from the oven.

4. Remove the front screws from the left and right oven rack supports and remove the supports from the oven liner.

5. Remove the screws from the convection baffle and remove the baf fle from the back of the oven liner.

6. Remove the hex nut from the front of the convection blade. NOTE: The nut has leftrotating threads.

TECH TIP!!

The convection blade hex nut has left-rotating threads.

7. Remove the flat washer and e-ring from the convection blade and remove the blade from the motor shaft.

8. Remove the screws from the pan and remove the pan.

9. Remove the motor screws from the bracket and remove the motor from the bracket.

10. Disconnect the two wires from the fan motor terminals.

11. Connect the brown wire (#45) to the right terminal of the new convection fan motor , and the white wire (#44) to the left terminal, then install the motor assembly.

12. Reassemble the oven.

Page 89

Page 92

CM Oven Service Manual Lit. No. 94-30-006B

Oven Liner

White Wire (#44)

Brown Wire (#45)

Fan Motor

Bracket with Insulation

Fan Motor Screws

Pan

Convection Blade

Top Screw

E-Ring

Flat Washer

Hex Nut (Left-Rotating Thread)

Top Screw

Convection Baffle

Bottom Screws

Page 90

Page 93

CM Oven Service ManualLit. No. 94-30-006B

Halogen Lamp

Lamp Cover

Lamp Holder

REMOVING A HALOGEN LAMP HOLDER

WARNING

Turn off the electrical power circuit to the oven at the main junction box before servicing this unit.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

Refer to illustration, right, for the following steps.

1. Turn off the electrical power to the oven.

2. Remove the oven racks.

3. Remove the oven rack support for the halogen lamp holder you are removing.

CAUTION: Make sure that the halogen bulb is cool before you remove it in the next step.

4. Pull the lamp cover out of the halogen lamp holder and remove the bulb.

5. Pry the lamp holder out of the oven liner and cut the wires approximately 2" from the lamp holder body. CAUTION: Be

careful not to chip or scratch the oven liner when you pry the lamp holder out of the cutout.

6. Cut the plug off the new lamp holder.

7. Connect the cut wires to the new lamp holder with two red inline splices. After you connect the wires, pull on them to make sure that the inline splices are secure.

8. Gently pull the lamp holder wires up into the plenum area until you can see the red wire splices in the plenum area.

9. Reassemble the oven.

TECH TIP!!

Make sure that the two red inline splices ar e in the top plenum area and not in the oven heat zone.

Page 91

Page 94

CM Oven Service Manual Lit. No. 94-30-006B

Upper Y el (102) Lower Org (112)

Upper Wht (103) Lower Wht (113)

Upper Blk (104) Lower Blk (114)

Upper Blk (12) Lower Blk (92)

Front Of Oven

Screw (2)

Douible Line Break Relay

REMOVING THE LAMP TRANSFORMER &

LOWER OVEN DOUBLE LINE BREAK RELAY

WARNING

Turn off the electrical power circuit to the oven at the main junction box before servicing this unit.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. Turn off the electrical power to the oven.

2. Open the upper oven door.

3. Remove the control panel and display head (see Page 11 for the procedure).

4. Remove the front subpanel (see Page 10).

5. To remove the lamp transformer (see il-

lustration, below):

6. To remove an old oven relay (see Illustration, below):

a) Remove the screws and disconnect the

wires from the relay terminals.

b) Install the new oven stalled fan relay

with the terminals positioned as shown and reconnect the wiring.

a) Remove the screws and disconnect the

wires from the terminals.

b) Install the new lamp transformer and

reconnect the wiring.

Secondary

Winding Primary

Winding

7. Reassemble the oven.

Page 92

Page 95

CM Oven Service ManualLit. No. 94-30-006B

REMOVING the OVEN LIGHT SWITCH, the OVEN DOOR LATCH

ASSEMBLY and the HI-TEMP CUTOUT in LOWER OVEN

WARNING

Turn off the electrical power circuit to the oven at the main junction box before servicing this unit.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

Refer to illustration on Page 94 for the following steps.

1. Turn off the electrical power to the oven.

2. Open the oven door for the component you wish to remove.

3. To remove the lower air vent grille, re- move the two front oven door latch screws, (see illustration, below), then pull the posts on the ends of the air vent grille out of the catches in the chassis.

4. To remove the oven light switch, discon- nect the wires from the terminals, press in on the locking arms, and push the switch out of the vent (see Inset 1, Page

94).

5. To remove the oven door latch assembly (see Inset 2, Page 94):

a) Use a 1/4" ratchet and a 1/4" thin-wall

socket and remove the two front hexhead screws from the latch bracket.

b) Pull the latch assembly to the right so

that the flange on the left side clears the bracket, and then pull it forward as far as the wires will allow.

c) Remove the wires from the switch con-

nectors and the motor wires from the main harness.

d) To replace a door lock or door unlock

switch on the latch assembly, remove the two screws from the switch body, and remove the switch.

6. To remove the hi-temp cutout (see Inset 3, Page 94):

a) Remove the two 1/4" hex-head screws

from the bracket.

b) Remove the hi-temp cutout and discon-

nect the wires.

7. Install the replacement component.

8. Reassemble the oven.

PULL TOP OF VENT GRILLE FORWARD

TO REMOVE POST FROM CATCH

PULL TOP OF VENT GRILLE FORWARD

OVEN DOOR

LATCH SCREWS

LOWER AIR VENT GRILLE

Page 93

TO REMOVE POST FROM CATCH

CATCH

OVEN CHASSIS

POST

Page 96

CM Oven Service Manual Lit. No. 94-30-006B

REMOVING the OVEN LIGHT SWITCH, the OVEN DOOR

LATCH ASSEMBLY and the HI-TEMP CUTOUT

Inset 1

NORMALLY OPEN

TECH TIP!!

Y ou will need the following tools to remove the components:

1/4" ratchet 1/4" thin-wall socket #2 Phillips Offset Screwdriver

OVEN DOOR LATCH SCREWS

(GOLD) CONTACTS

DOOR OPEN = SWITCH OPEN

NORMALLY CLOSED

DOOR OPEN =

SWITCH CLOSED

Upper Oven

Wht (05)

Lower Oven

Wht (55)

Upper Oven

Motor (07 & 08)

Lower Oven

Motor (57 & 58)

Bracket

SCREWS

Wht

Hex-Head Screw

UPPER

AIR VENT

GRILLE

Org

N.O.

OVEN DOOR LATCH

Com

Latch

Interlock

Switch

Upper Oven

Wht (01& 02)

Lower Oven

Wht (51& 52)

Unlock

Switch

Inset 2

N.O.

Com

Upper Oven

Wht (02 & 03)

Wht (52 & 53)

Hex-Head Screw

Upper

Oven

Wht (06)

Lower Oven

Wht (56)

Lower Oven

AIR VENT GRILLEAIR VENT GRILLE

Hi-Temp

SCREWS

Cutout

Inset 3

Reset Button

Hex-Head Screw

Wire Connector

Slide Latch Flange From Under Bracket

Page 94

Page 97

CM Oven Service ManualLit. No. 94-30-006B

REMOVING THE AIR SWITCHES

WARNING

Turn off the electrical power circuit to the oven at the main junction box before servicing this unit.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

NOTE: The air flow to the air switch in the lower oven base compartment of all 27" S-Series ovens has been improved with the addition of an air diverter (#16-10-101). This improvement has been made to all 27" and 30" ovens built in l998. The new air diverter is located on the right side of the lower oven base compartment (see illustration below). If you encounter a 27" oven that was built in 1997 with no oven heat, due to the air switch not closing, order and install the new diverter . You will not see any error code messages in control display window if these problems occur.

Refer to illustration on Page 96 for the following steps.

1. Turn off the electrical power to the oven.

2. Open the lower oven door. The bottom trim mounting screws (see Inset 1, Page

96) are visible at each side of the oven door, below the left and right hinges.

3. Remove the two screws from the bottom trim, pull it forward, and remove it.

4. Remove the two front switches from the air switch bracket and flange, and pull the air switch bracket assembly forward so you can access the switches (see Inset 2, Page 96).

5. T o r emove an air switch from the bracket, remove the two screws from the switch body, and disconnect the wires from the terminals (see Inset 3, Page 96).

6. Install the new air switch in the mounting bracket.

7. If you intend to install the air switch diverter , do so at this time. Make sure that the spacing between the air switch paddle and the end of the diverter is as shown below.

8. Reassemble the oven.

Oven

Base

Page 95

Air Diverter #16-10-101

Air Switch

Paddle

1-1/8

Max

NOTE: After mounting the air diverter, bend the arm, as necessary, so that the space between the air switch paddle and the end of the arm is as shown.

#8A x 3/8

Sheet Metal Screw

#14-91-102

Page 98

CM Oven Service Manual Lit. No. 94-30-006B

REMOVING THE AIR SWITCHES

Mounting Screws

Bracket

Inset 3

Bottom Trim

Inset 1

Side View

Screw

AIR SWITCH

Inset 2

Upper Oven

Air Switch

Mounting

Screws

Flange

Air Switch

Bracket

Bottom Trim

Lower Oven

Air Switch

Mounting

Screws

Page 96

Page 99

REMOVING A BLOWER

CM Oven Service ManualLit. No. 94-30-006B

WARNING

Turn off the electrical power circuit to the oven at the main junction box before servicing this unit.

CAUTION

When you work on the oven, be careful when handling the sheet metal parts. There are sharp edges present and you can cut yourself if you are not careful.

1. Turn off the electrical power to the oven.

2. T o make servicing easier , remove the oven door (see Page 99).

3. To remove the upper blower (see Figure

A, Page 5-98):

a) Remove the oven from the wall. b) Remove the screws from the front and

rear plenum covers and remove the covers (see Page 10 for the procedure).

c) Remove the three screws from the

blower motor bracket on the back of the plenum and turn the assembly around so that the back faces you.

d) Remove the three screws that mount

the motor to the bracket.

e) Disconnect the four wires from the mo-

tor terminals.

f) Install the new blower in the mounting

bracket and mount the assembly to the plenum.

4. To remove the lower blower (see Figure

B, Page 5-98):

a) Remove the oven from the wall. b) Remove the rear panel from the oven. c) Remove the four bracket screws (1,2,6,

& 7) from the back of the oven.

d) Remove the three blower screws (3, 4,

& 5) from the bracket and remove the motor.

e) Loosen the wire ties and remove the

two motor wires from the rest of the wire harness.

f) Install the new blower in the mounting

bracket, mount the assembly to the back of the oven, and connect the wires.

g) Install the motor wires in the wire har-

ness ties with the rest of the wires and dress them neatly.

5. Reassemble the oven.

Page 97

Page 100

CM Oven Service Manual Lit. No. 94-30-006B

REMOVING A BLOWER

BACK OF PLENUM

Mounting Bracket

White

(98)

White

(24)

Lower Blower

Figure B

Screw

Lt. Blue

(97)

Dk. Blue

(23)

Blower Wire (24) To Upper Blower Motor

Screw

Upper Blower

Figure A

Blower Wire (23) To Upper Blower Motor

Blower Bracket

Page 98

Thermador CM301B, CM301W, CM302W, CM302S, CM301S Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual