Microtech
© 1998-2013 J. Carlton Gallawa
All Rights Reserved Worldwide
Last updated 1/2012
Fix Microwave Ovens Like A Pro!

This page includes case histories of the brands:

Sharp to Whirlpool

Page 2

 

Instructions On How To Use These Repair Histories For Troubleshooting And Repairing Microwave Ovens

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

Please Note:

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

  Important Safety Information

Repairing a microwave oven is a dangerous task. For your personal safety, please do not proceed unless you fully understand and are prepared to follow carefully these appropriate safety precautions . .

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.

© 1996-2013 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:
Problem:
Solution:
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
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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
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Operation, Maintenance, Troubleshooting and Repair
J. Carlton Gallawa
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© 1998-2013 J. Carlton Gallawa . All Rights Reserved Worldwide