Sharp R21lcf Service Manual

PRECAUTIONS TO BE OBSERVED BEFORE AND
DURING SERVICING TO AVOID POSSIBLE EXPO-
SURE TO EXCESSIVE MICROWAVE ENERGY
BEFORE SERVICING
CHAPTER 1. WARNING TO SERVICE PERSONNEL
CHAPTER 2. MICROWAVE MEASUREMENT PRO-
CEDURE
CHAPTER 3. FOREWORD AND WARNING
CHAPTER 4. PRODUCT DESCRIPTION
CHAPTER 5. GENERAL INFORMATION
CHAPTER 6. OPERATIONCHAPTER 7. TROUBLESHOOTING GUIDE 
CHAPTER 8. TEST PROCEDURES
CHAPTER 9. TOUCH CONTROL PANEL ASSEMBLY
CHAPTER 10. PRECAUTIONS FOR USING LEAD-
FREE SOLDER
CHAPTER 11. COMPONENT...

CONTENTS
PRECAUTIONS TO BE OBSERVED BEFORE AND
DURING SERVICING TO AVOID POSSIBLE EXPO-
SURE TO EXCESSIVE MICROWAVE ENERGY
CHAPTER 1. WARNING TO SERVICE PERSONNEL
[1] Before Servicing .........................................1-1
[2]  When the testing is co mpleted, ..................1-1
[3] After repairing .............................................1-1
CHAPTER 2. MICROWAVE MEASUREMENT PRO-
CEDURE
[1] Requirements: .............. ..............................2-1
[2] Preparation for testing:...

R21LCF
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R21LCFService Manual PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID
POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY
BEFOR SERVICING
PRECAUTIONS TO BE OBSERVED BEFORE AND
DURING SERVICING TO AVOID POSSIBLE
EXPOSURE TO EXCESSIVE MICROWAVE
ENERGY
(a) Do not operate or allow the oven to be operated with the door open.
(b) Make the following safety checks on all ovens to be serviced before activating the magnetron or other microwave source, and make repairs as necessary: (1)...

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R21LCFService Manual CHAPTER 1. WARNING TO SERVICE PERSONNEL
Microwave ovens contain circuitry capable of producing very high voltage and cu rrent, contact with following parts may result in a severe, possibly
fatal, electrical shock.
(Example)
High Voltage Capacitor, High Voltage Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..
Read the Service Manual carefully and follow all instructions.
[1] Before Servicing
1. Disconnect the power supply cord  ,...

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R21LCFService Manual CHAPTER 2. MICROWAVE MEASUREMENT PROCEDURE
[1] Requirements:
1. Microwave leakage limit (Power density limit): The power density of microwave ra diation emitted by a microwave oven should no t exceed 1mW/
cm2 at any point 5cm or more from the external surface of the  oven, measured prior to acquisition by a purchaser, and thereafter ( through the use-
ful life of the oven), 5 mW/cm2 at any point 5cm or more from the external surface of the oven. 
2. Safety interlock...

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R21LCFService Manual CHAPTER 3. FOREWORD AND WARNING
[1] FOREWORD
This Manual has been prepared to provide Sharp Electronics Corp. Service Personnel with  Operation and Service Information for the SHARP
MICROWAVE OVEN, R-21LCF.
It is recommended that service personnel carefully study the entire  text of this manual so that they will be qualified to render satisfactory customer
service.
Check the interlock switches and the door seal carefully. Special  attention should be given to avoid...

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R21LCFService Manual CHAPTER 4. PRODUCT DESCRIPTION
[1] SPECIFICATIONS
ITEM DESCRIPTION
Power Requirements120 Volts 
14 Amperes
60 Hertz
Single phase, 3 wire grounded
Power Output 1000 watts (IEC Test procedure)
Operating frequency 2450 MHz 
Outer case Dimensions Width  20-1/2 (520mm)
Height 12-1/8 (309mm)
Depth  16       (406mm)
Cooking Cavity Dimensions Width 13-7/8  (353mm)      
NOTE: Internal capacity is calculated by measuring
Height  8-1/ 8 (207mm)                  maximum width,...

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R21LCFService Manual CHAPTER 5. GENERAL INFORMATION
[1] GROUNDING INSTRUCTIONS
This oven is equipped with a three prong grounding plug. It must be plugged into a wall receptacle that is properly installed and grounded in accor-
dance with the National Electrical  Code and local codes and ordinances.
In the event of an electrical short circui t, grounding reduces the risk of electric shoc k by providing an escape wire for the electric current.
WARNING: Improper use of the grounding plug can...

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R21LCFService Manual CHAPTER 6. OPERATION
[1] DESCRIPTION OF OPERATING SEQUENCE 
The following is a description of com ponent functions during oven operation.
1. OFF CONDITION
Closing the door activates door sensing switch and secondary inter-
lock switch. (In this condition, the monitor switch contacts are opened.)
When oven is plugged in, 120 volts A.C.  is supplied to the noise filter
and the control unit (Figure O-1).
2. COOKING CONDITION
When the Light Up Dial is tur ned, the following...

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2. Cooking Condition
                                                        
Figure O-2. Oven Schematic-Cooking Condition
[3] DESCRIPTION AND FUNCTION OF COMPONENTS
1. DOOR OPEN MECHANISM
The door is opened by grasping the door handle, refer to Figure D-1.
When the door handle is grasped,  the handle lever is pulled. And then
the upper and lower latch heads are moved upward by the handle
lever, and they are released from the latch hook. Now the door will
open.
                     Figure...