Sharp R-21LCF

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. OPERATION
CHAPTER 7. TROUBLESHOOTING GUIDE
CHAPTER 8. TEST PROCEDURES
CHAPTER 9. TOUCH CONTROL PANEL ASSEMBLY
CHAPTER 10. PRECAUTIONS FOR USING LEAD-
FREE SOLDER
CHAPTER 11. COMPONENT REPLACEMENT AND
ADJUSTMENT PROCEDURE
CHAPTER 12. CIRCUIT DIAGRAMS
Parts List
S7607R21LCFP/
LIGHT DUTY COMMERCIAL
MICROWAVE OVEN
R-21LCF
SERVICE MANUAL
R21LCF
MODEL
CONTENTS
SHARP CORPORATION
This document has been published to be used
for after sales service only.
The contents are subject to change without notice.
In the interest of user-safety the oven should be restored to its original
condition and only parts identical to those specified should be used.
WARNING TO SERVICE PERSONNEL: Microwave ovens contain
circuitry capable of producing very high voltage and current, con-
tact with following parts may result in a severe, possibly fatal,
electrical shock. (High Voltage Capacitor, High Voltage Power
Transformer, Magnetron, High Voltage Rectifier Assembly, High
Voltage Harness etc..)
1000W/R-21LC
C
O
M
M
E
R
C
I
A
L
M
I
C
R
O
W
A
V
E
O
V
E
N
TIME GUIDE FORONE SERVING
15
- 30
sec.
Bagel, Roll
Muffin,
Pastr
y
Pie
Slice
30-60sec.
Hot Dog
PizzaSlice
Small
Sandwich
1-2
min.
Beverage, Soup
LargeSand
wich
Popc
orn, 1.5o
z.
2-3
m
in.
Casserole
, Stew
Chili, Ch
owder
Popcor
n, 3.5oz.
With
th
e do
or closed,turn t
h
e t
i
m
e
r to
the desired tim
e. Oven wil
lb
egin
o
pera
ti
n
g
i
mmediately.
Toshu
toven off ma
nually,returnti
mer
to "0".
INSTRUCTIONS
0
10
20
30
40
50
1
1.5
2
2.5
3
4
5
6
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T

Sharp R-21LCF Specifications

General

Turntable	-
Cord length	1.5 m
Control type	Rotary
Product color	Gray
Timer duration	6 min
Microwave power	1000 W
Built-in display	Yes
Internal coating	Stainless steel
Appliance placement	Countertop
Heat source	Electric
Current	14 A
Connected load	- W
AC input voltage	120 V
AC input frequency	60 Hz
Package weight	19960 g

Weight and Dimensions

Depth	406.6 mm
Width	520.7 mm
Height	308 mm
Weight	16780 g
Interior dimensions (W x D x H)	352.4 x 371.4 x 206.4 mm

Summary

Precautions for Microwave Energy Exposure

Before Servicing Precautions

Warning to Service Personnel

Before Servicing

Procedures for safe servicing before operating the oven.

When the testing is completed,

After repairing

Microwave Measurement Procedure

Requirements

Specifies limits and conditions for microwave leakage tests.

Preparation for testing

Leakage test

Detailed procedure for performing the microwave leakage test.

Foreword and Warning

Warning

Danger

Highlights specific high-voltage hazards during servicing.

General Information

Grounding Instructions

Troubleshooting Guide

Troubleshooting Chart

A table guiding diagnosis of common oven problems.

Test Procedures

Procedure A: Magnetron Assembly Test

Steps to test the magnetron assembly for proper function.

Procedure B: Power Transformer Test

Instructions for testing the power transformer's resistance.

Procedure C: High Voltage Rectifier Test

Method to test the high voltage rectifier assembly.

Procedure D: High Voltage Capacitor Test

How to test the high voltage capacitor for shorts or opens.

Procedure E: Thermal Cut Out Test

Procedures to test thermal cut-out switches.

Procedure F: Secondary Interlock Switch Test

Testing the secondary interlock switch operation.

Procedure F: Primary Interlock System Test

Testing the primary interlock system components.

Procedure G: Monitor Switch Test

How to test the monitor switch for correct operation.

Procedure H: Blown Monitor Fuse Test

Steps to diagnose and test related components for a blown monitor fuse.

Procedure J: Control Panel Assembly Test

Troubleshooting symptoms related to the control panel.

Procedure L: Relay Test

Testing the operation of relays RY1 and RY2.

Component Replacement and Adjustment Procedure

Warning

Critical safety warnings for high voltage and microwave energy.

Outer Case Removal

Power Transformer Removal

High Voltage Rectifier Assembly and High Voltage Capacitor Removal

Magnetron Removal

Control Panel Assembly Removal

Door Sensing SwitchSecondary Interlock Switch and Monitor Switch Removal

Door Sensing SwitchSecondary Interlock Switch and Monitor Switch Adjustment