Microtech © 1998-2002 J. Carlton Gallawa All Rights Reserved Worldwide Last updated 1/2002

This page includes the brands: Kenmore (Sears) to Montgomery Wards Page 2

Microwave Oven Troubleshooting and Repair Instructions

1. After reading the safety precautions , find the brand and model number, or the number closest to the model you are repairing.
2. Find the symptom(s) that most closely match the symptom(s) being displayed by the oven you are repairing.
3. Follow the specific troubleshooting and/or repair instructions to complete the repair. Click on highlighted text for a detailed explanation of that procedure.
4. Since this database is constantly being updated and appended, if you don't find what your looking for, try again at a later time.
5. Click here    if you would like to be notified by e-mail when this page is updated. 

Please Note:

• The manufacturers' part numbers and prices listed here are subject to change without notice.
• The individual model numbers are not necessarily arranged in numerical order

Important Safety Information

Disclaimer: The author assumes no liability for any incidental, consequential or other liability from the use of this information. All risks and damages, incidental or otherwise, arising from the use or misuse of the information contained herein are entirely the responsibility of the user.  Although careful precaution has been taken in the preparation of this material, we assume no responsibility for omissions or errors.

© 1996-2002 J. Carlton Gallawa
All Rights Reserved Worldwide
© Copyright Information
 

MICROWAVE OVEN REPAIR CASE HISTORY DATABASE (CONT'D)

LITTON

Model: 2240.000

Symptom: Will not start

Problem: Defective "start:pad on touch panel

Solution: Replace touch panel. Part # M7D818, sub to 92794P01. Price:$45.00 or more

LITTON

Model: 465.000

Symptom: Oven makes a grinding noise

Problem: Blower motor fan blade is slipping on the shaft

Solution: Either replace fan blade, or, if hub is not worn too severely, super-glue the blade to the shaft (Do not allow glue to run down the shaft into the motor housing)

LITTON

Model: 7000.000

Symptom: Control panel will not program

Problem: Defective mylar touch panel

Solution: Replace touch panel. Part # M4D474. Price:$98.50 or more

LITTON

Model: 80-50.000

Symptom: Control panel display is dead

Problem: Deteriorated solder joints on printed circuit board

Solution: Inspect foil side of PCB for cracked, deteriorated solder connections. Reinforce and re-solder as necessary

MAGIC CHEF

Models: DM130KG, DM15K-7BR, DM15K-7BS

Symptom: Went dead immediately after pressing "start," or flickered and went dead

Problem: Fuse not secure in fuse holder

Solution: Fuse holder is mounted on the printed circuit board. So, the most practical solution is to either (1) squeeze the fuse clips together to increase their grip on the fuse, or (2) solder the new fuse directly to the fuse clips. Do not apply too much heat, or the internal fuse connections will melt. Generic fuses available at appliance parts suppliers for $1.00 to $2.00 each

MAGIC CHEF

Model: DM15K-78S-N

Symptom: Makes metallic noise after cooking for awhile

Problem: After prolonged cooking, the center of the stirrer cover begins to sag, causing the edges of the stirrer blade to scrape against it

Solution: Replace the stirrer blade, Magic Chef part # 51001048; and replace the stirrer cover, part # 51001028

Note: As of this writing, this did not effectively eliminate the problem. Only an improved stirrer cover will correct the sagging problem

MAGIC CHEF

Models: DM46K-15B, M126B

Symptom: Oven went dead while cooking

Problem: Fuse is not securely fastened into fuse clips, which, in many models, are mounted on the printed circuit board.

Solution: Either (1) Squeeze the fuse clips together to tighten their grip, and replace the fuse, or (2) Install a new fuse and tack it into the fuse clips by soldering the endcaps to the clips. Fuse:Magic Chef part # 51001230, or use generic 15 amp fuse, about $1.50

MAGIC CHEF

Model: DM85K

Symptom: Dead

Problem: Fuse is not securely fastened into fuse clips, which, in many models, are mounted on the printed circuit board.

Solution: Either (1) Squeeze the fuse clips together to tighten their grip, and replace the fuse, or (2) Install a new fuse and tack it into the fuse clips by soldering the endcaps to the clips. Fuse:Magic Chef part # 51001230, or use generic 15 amp fuse, about $1.50

MAGIC CHEF

Model: M15B-7P

Symptom: Was working fine, then went dead

Problem: Weakened fuse clips in the fuse receptacle causing fuse to melt due to resistive heat. Usually indicated by a bead of solder leaching out from either endcap , and/or evidence of overheating (or burned spot) at the endcap, fuse clip, or terminal connection

Solution: Replace 15 amp fuse (about $1.00) and receptacle (about $2.00)

Additional Inf: Generic fuse holders are available at appliance and electronic part suppliers

MAGIC CHEF

Model: M61C-8P

Symptom: Makes a grinding, crackling noise during cook

Problem: Defective high voltage relay (also called power relay)

Solution: Replace high voltage relay. Magic Chef part # 0112002V (about $30.00)

MENUMASTER

Model: FS14EVP.C

Symptom: Oven cuts out after prolonged operation

Problem: Defective right-side blower assembly is allowing the magnetron to overheat, thus causing its thermal protector to open

Solution: Replace defective blower motor. Part # M12D81 (about $45.00)

MENUMASTER

Model: FSP-10.D

Symptom: Sparking

Problem: Stirrer cover has warped and is causing a bind with the stirrer blade

Solution: Clean (with sandpaper if necessary - never use steel wool) away all traces of carbon. Replace stirrer blade, part # M45D39. Price:about $ 12.00. Replace stirrer cover, part # M35D53. Price:about $14.00

MENUMASTER

Model: LC10 (All revisions)

Symptom: Dead

Problem: Shorted high voltage capacitor caused line fuse to blow

Test: High Voltage Capacitor Test

Solution: Replace shorted capacitor. Part # M10D91, sub to R0156906. Price:$about $50.00. Also replace 30 amp line fuse. Part # M4D88. Price:$8.00

MITSUBISHI (MGA)

Model: ET-712

Symptom: When a cook operation is started, the oven emits a deep groan and, within about 3 seconds, the fuse blows and the oven goes dead

Problem: Defective power-control triac is causing the line fuse to open

Test: Triac Test

Solution: Replace the triac (GE part # WB27X5085) and install a new 15 amp fuse

Submitted by: Bob M., South Texas, United States

MOBIL CHEF

Model: AXM-1200

Symptom: No heat

Test: High Voltage Diode Test

Problem: Replace defective diode (rectifier)

Solution: Replace shorted high voltage diode (rectifier). Generic replacement available at appliance parts suppliers for about $10.00 to $12.00

MODERN MAID

Model: 5656798

Symptom: oven runs but does not heat

Problem: Burned connectors on upper interlock switch.

Solution: Repair the burned connector by either replacing the slip-on connector or soldering the wire directly to the switch. Note:If the terminal was severely burned, the switch should also be replaced.

Test: Interlock Switch Test

A generic microswitch rated at 15 or 16 amps with appropriate terminal configuration will suffice.

MONTGOMERY WARDS

Model: KSA-8006A

Symptom: Arcing inside of cooking area

Problem: Waveguide cover is breaking down and arcing

Solution: Clean affected area, and replace waveguide cover. See procedure

MONTGOMERY WARD

Model: KSA-8127A

Symptom: Control panel is dead

Problem: Surge protection circuit on printed circuit board is damaged

Solution: Repair foil trace , and replace varistor, price:$3.00 - $4.00

Procedure: Foil Pattern and Filter Coil Repair Procedure

MONTGOMERY WARDS

Model: KSA-8263A

Symptom: Control panel is dead, but the oven light works

Problem: Defective solder joint on printed circuit board.

Solution: Repair deteriorated solder connection between diodes D10 & D11

MONTGOMERY WARDS

Model: KSA-8287A

Symptom: The oven reaches the correct convection temperature setting, then it goes dead

Problem: Defective convection sensor (thermistor)

Test: Thermistor Test

Solution: Replace convection thermistor. Part # 68518075. Price:about $12.00

MONTGOMERY WARDS

Model: KSA-8263A

Symptom: Dead when customer went to use

Problem: Weakened fuse clips in the fuse receptacle causing fuse to melt due to resistive heat. Usually indicated by a bead of solder leaching out from either endcap , and/or evidence of overheating (or burned spot) at the endcap, fuse clip, or terminal connection

Solution: Replace 15 amp fuse (about $1.00) and receptacle (about $2.00)

Additional Information: Generic fuse holders are available at appliance and electronic part suppliers

End section K to O

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Parts Suppliers and Manufacturer Contacts You can contact these parts suppliers and microwave oven equipment manufacturers directly for replacement parts, product literature, dealer locations, technical assistance, etc. Please e-mail additions or corrections to: j.gallawa@cox.net Glossary of Electronic and Microwave Oven Related Terms  Let us know what you think, or submit your own repair tip j.gallawa@cox.net

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The COMPLETE MICROWAVE OVEN SERVICE HANDBOOK Operation, Maintenance, Troubleshooting and Repair Copyright © 1989-2002 by J. Carlton Gallawa