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

This page includes case histories of the brands: Sharp to Whirlpool Page 2

1. After reading the safety precautions, find the brand and model number, or the number closest to the model you are repairing (you may want to use your browser's find feature).
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

We hope that you find the information here helpful.. .

  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)

SHARP

Model: R8320

Symptom: Blower fan comes on by itself

Problem: Defective, corroded thermistor (mounted above cavity ceiling).

Solution: Replace thermistor, part # FH-HZ0018WRK0. Price:about $42.00

SHARP

Model: R-1820

Symptom: Oven went dead while cooking

Problem: Shorted high-voltage transformer

Test: High-Voltage Transformer Test

Solution: Replace high-voltage transformer. Generic replacements may be available at appliance parts suppliers. Price:$90.00 to $120.00

SHARP

Model: R-1830

Symptom: Dead

Problem: Built-in surge protection on printed circuit board has opened. This circuit consists of a fine foil pattern (or filter coil - depending on the model) that acts to fuse the primary side of the low-voltage transformer.

Solution: Rebuild the surge protection circuit. Replace the varistor . Also replace opened low-voltage transformer.

Procedure: Foil Pattern/Filter Coil Repair Procedure

SHARP

Model: R-21AD

Symptom: Oven had an electrical burning smell and was smoking, then it went dead.

Problem: Shorted high-voltage transformer

Test: High-Voltage Transformer Test

Solution: Replace high-voltage transformer. Sharp part # RTRN-0165WRE0. Price:$175.00

SHARP

Model: R-21AP, R-3A66, R-3A84, R-4A43, R-4A53, R-4A60, R-4B82, R-4E80, R-4X84, R-5A51, R-5A54, R-5A56, R-5A83, R-5A85, R-5A86, R-5A96, R-7A85

Symptom: Oven is found dead after receiving a power surge, either from a lightning strike or other transient voltage spike or power disturbance.

Problem: Built-in surge protection on printed circuit board has opened. This circuit consists of a fine foil pattern (or filter coil - depending on the model) that acts to fuse the primary side of the low-voltage transformer.

Solution: Rebuild the surge protection circuit. Replace the varistor , Sharp part # RH-VZA016DREO

Procedure: Foil Pattern/Filter Coil Repair Procedure

SHARP

Model: R-22AP

Symptom: The oven changes time by itself

Problem: Deficient solder joints on the control panel.

Solution: Repair cold solder joint at PIN 2 of transistor Q1

SHARP

Model: R-4H80

Symptom: Intermittently goes dead

Problem: Cracked solder joint at RL2 on main printed circuit board

Solution: Repair defective solder joint at RELAY 2

SHARP

Model: R-23BP, R-23BT

Symptom: Digits on right side of display are flickering

Problem: Capacitor C5 on main printed circuit board is either defective or has bad solder joints

Solution: Replace C5 (470 MFD 35V) or repair solder joints as necessary

SHARP

Model: R-3A57

Symptom: Carousel starts then stops

Problem: Defective turntable motor and broken turntable coupling

Solution: Replace turntable motor, Sharp part # RMOTDA161WREO. Install new coupling, Sharp part # NCPL-AO45WRFO

SHARP

Model: R-4070

Symptom: Door opening handle is broken

Problem: Broken open lever.

Solution: Replace broken lever. Sharp part # MLEVPA039WRFO. Price:$4.95

SHARP

Model: R-4A72

Symptom: Dead

Problem: The connector to the magnetron thermal fuse has burned loose.

Solution: Repair burned connection. Replace thermal fuse if necessary.

SHARP

Model(s): R-4A47, R-4A57, R-4A77, R-4A87, R-4A97, R-4H07, R-4H17

Symptom: Vibration or loud buzzing noise while cooking

Problem: This is caused by a vibration between the outer cover and the oven base plate.

Solution: Add a piece of rubber to act as a cushion. Use Sharp part# PCUSGB025MRE or suitable piece of material. The cushion should be placed along the vertical edge of the base plate, next to the high-voltage transformer, so that it is sandwiched between the outer cover and the base plate when the cover is installed.

SHARP

Model: R-5A50, R-5A82

Symptom: Carousel not turning

Problem: Broken turntable coupling

Solution: Replace turntable coupling.

SHARP

Model: R-5A84

Symptom: Dead-Burning smell

Problem: Shorted high-voltage transformer

Test: High-Voltage Transformer Test

Solution: Replace transformer. Sharp part # RTRN-B005MRE0. Also install new line fuse (FFS-BA013/KIT - kit includes interlock switch)

SHARP

Model: R-5W34

Symptom: Oven starts and counts down, but nothing else works. The blower doesn't run and the oven doesn't heat

Problem: Defective transistor Q82 on main printed circuit board

Solution: Replace Q82 (DTC143ES), Sharp part # VSDTC143ES/-3

SHARP

Model: R-7710

Symptom: Timer never shuts off.

Problem: Defective timer

Solution: Replace timer assembly--Part # QSWTE0101WRE0. Price:around $56.05

SHARP

Model: R-8310

Symptom: Convection heat is too hot-burning things.

Problem: Opened thermistor .

Test: Thermistor Test

Solution: Replace thermistor. Sharp part # FH-HZ0017WRKO. Price:about $39.95

SHARP

Model: R-8310

Symptom: Oven makes a grinding or dragging noise.

Problem: Convection fan bearing is worn

Solution: Replace shaft and bearing:Shaft and bearing kit, part # FBRGM0017WREO; price:around $39.95

SHARP

Model: R-9470

Symptom: No heat

Problem: Defective solder joints on the power relay circuit.

Solution: Inspect printed circuit board for cracked, burned, or deteriorated solder joints. Clean, reinforce, re-solder as necessary.

SHARP

Model: R-9H83

Symptom: Control panel fades in and out (or may be completely dead)

Problem: Cracked solder joint on Pin 4 of low-voltage transformer, T1

Solution: Examine printed circuit board. Clean, reinforce and resolder cracked and deficient solder connections as necessary.

SHARP

Model: R7360

Symptoms:

• Cook relay contacts welded closed.
• Magnetron comes on when door closed.
• Weak heat.
• Eventually goes dead

Problem:

• Magnetron overheated and caused temperature fuse to open.
• Magnetron damaged by continuous "no-load" operation.
• Cook relay contacts damaged by defective drive circuit causing relay to chatter when energizing.
• Leaky capacitor in relay drive circuit.

Solution:

• Replace leaky capacitor, C80 (.47Mfd 50V)
• Replace cook relay, RY2 (15 DC coil). Part # RRLYU2076YAZZ
• Replace magnetron (RV-MZ0161WRE0) and temperature fuse (QFS-T0018MRE0)

SHARP

Model: R7804

Symptom: Arcing during cook.

Problem: Buildup of cooking debris between waveguide cover metal flange eventually breaks down and carbonizes causing arcing to occur.

Solution: First clean (and sand if necessary) away all carbon buildup, grease and cooking debris from in and around waveguide opening. Then, replace the waveguide cover, part # ** Price:About $7.00 - $9.00.

SHARP

Model: R9530

Symptom: None of the pads on the control panel will not respond.

Problem: Defective control board.

Test:Check capacitors C6, C7 and C9 on main printed circuit board for obvious deteriorated solder connections.

Solution: Repair (or replace) capacitors if necessary. If capacitors OK, replace main printed circuit board,, part # CPWBF022SWRK0

SUNBEAM

Model: 24011

Symptom: Switched the selector control and the unit went dead

Problem: Weakened fuse clips on 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 (burned spot) at the terminal connection

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

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

To Page 3 (R to Z) 

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

Looking for secure employment or a lucrative part-time job? Read on!  This extraordinarily comprehensive new CD-ROM is for YOU! Here is THE definitive step-by-step instructional guide to making safe and successful (and profitable) repairs. The great thing about making money through the CD-ROM is that you can do it part-time or full-time. Plus, you make its price back on the first repair, and then over and over again! If you would like to learn more, click here Pictured to the left is an illustration from the CD-ROM's innovative Magnetron Cross-Reference and Replacement Guide--the most comprehensive cross reference resource in the industry

THE COMPLETE MICROWAVE OVEN SERVICE HANDBOOK 2000 Operation, Maintenance, Troubleshooting and Repair J. Carlton Gallawa