Sharp R-370EK

R-370EK
R-370ES
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 con-
tain circuitry capable of producing very high voltage and
current, contact with following parts may result in a severe,
possibly fatal, electrical shock. (High Voltage Capacitor, High
Voltage Power Transformer, Magnetron, High Voltage Recti-
fier Assembly, High Voltage Harness etc..)
TABLE OF CONTENTS
Page
PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO
AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY ...................INSIDE FRONT COVER
BEFORE SERVICING ......................................................................................................INSIDE FRONT COVER
WARNING TO SERVICE PERSONNEL................................................................................................................ 1
MICROWAVE MEASUREMENT PROCEDURE ................................................................................................... 2
FOREWORD AND WARNING...............................................................................................................................3
PRODUCT SPECIFICATIONS ..............................................................................................................................4
GENERAL INFORMATION................................................................................................................................... 4
OPERATION ..........................................................................................................................................................6
TROUBLESHOOTING GUIDE ............................................................................................................................10
TEST PROCEDURE ............................................................................................................................................12
TOUCH CONTROL PANEL .................................................................................................................................21
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ................................................................ 26
PICTORIAL DIAGRAM ........................................................................................................................................ 33
POWER UNIT CIRCUIT ......................................................................................................................................34
CPU UNIT CIRCUIT ............................................................................................................................................35
PRINTED WIRING BOARD .................................................................................................................................36
PARTS LIST ........................................................................................................................................................37
PACKING AND ACCESSORIES .........................................................................................................................39
S4112R370EPS/
R-370EK
R-370ES
MICROWAVE OVEN
MODELS
SERVICE MANUAL
SHARP CORPORATION
This document has been published to be used for after
sales service only.
The contents are subject to change without notice.
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7890

Sharp R-370EK Specifications

General

Brand	Sharp
Model	R-370EK
Category	Microwave Oven
Language	English

Summary

Microwave Oven Identification

Service Safety Precautions

Microwave Exposure Avoidance

Precautions to prevent excessive microwave energy exposure during servicing.

Before Servicing Procedures

Steps to prepare for servicing the microwave oven.

Service Personnel High Voltage Warning

Pre-Service Safety Procedures

Steps to prepare for servicing, including discharging the capacitor.

Post-Testing and Repair Procedures

Procedures to follow after testing and completing repairs.

Microwave Measurement Procedure

Leakage Test Requirements and Preparation

Specifies requirements, test setup, and preparation for microwave leakage testing.

Leakage Test Execution Steps

Step-by-step guide for performing the microwave leakage measurement.

Service Manual Introduction

General Operational Warnings

Important warnings and dangers related to high voltage components during servicing.

High Voltage Component Dangers

Lists specific components that pose an electrical shock hazard.

Product Specifications

Technical Specifications Overview

Details power, dimensions, control system, and safety standards.

General Information and Diagrams

Grounding and Electrical Requirements

Instructions for proper grounding and electrical supply for safe operation.

Oven Diagram and Control Panel Layout

Visual guide to oven parts and layout of the touch control panel.

Oven Operation Details

Operating Sequence and Power Levels

Describes the sequence of operation and variable power level cooking.

Sensor Cooking Functionality

Explains the sensor cooking mode, its operation, and an example.

Oven Schematic Diagrams

Off and Cooking Condition Schematics

Provides circuit diagrams for the oven in off and cooking states.

Component Descriptions and Functions

Door Mechanism and Safety Components

Details the door opening mechanism, safety switches, and monitor circuits.

Thermal Protection and Motor Functions

Explains thermal cut-outs, monitor fuse, and motor functions.

Troubleshooting Guide

General Troubleshooting Procedures

Guidelines for troubleshooting, including power disconnection and completion steps.

Specific Troubleshooting Scenarios

Focuses on troubleshooting a blown monitor fuse and related components.

Test Procedure Overview

Component Test Procedures: Magnetron and Transformer

Magnetron, Output Power, and Transformer Tests

Procedures for testing magnetron assembly, output power, and power transformer.

Component Test Procedures: High Voltage and Thermal Protection

High Voltage Rectifier, Capacitor, and Thermal Cut-Out Tests

Procedures for testing high voltage rectifier, capacitor, and thermal protection components.

Component Test Procedures: Switches, Relays, and Fuses

Interlock, Door Sensing, Monitor Switches, and Relay Tests

Procedures for testing various switches, the secondary interlock relay, and monitor switch.

Component Test Procedures: Control and Monitor Systems

Blown Monitor Fuse and Control Unit Diagnostics

Procedures for testing the monitor fuse and diagnosing control unit symptoms.

Component Test Procedures: Control and Key Units

Control Unit and Key Unit Testing Methods

Details on control unit symptoms and procedures for testing the key unit.

Component Test Procedures: Functions and Boards

Relay, Compu Defrost, and PWB Foil Pattern Tests

Procedures for testing relays, Compu Defrost, and printed wiring board foil patterns.

Component Test Procedures: AH Sensor

AH Sensor Initial Condition and Water Load Tests

Procedures for testing the AH sensor's initial condition and via a water load test.

Component Test Procedures: Sensor and Unit Verification

Sensor and Control Unit Verification Methods

Methods to verify AH sensor and control unit functionality through specific tests.

Component Test Procedures: Circuit Diagrams

Sensor Dummy Resistor Circuit Diagram

Details of the sensor dummy resistor circuit diagram for testing purposes.

Touch Control Panel Assembly Details

Control Unit Components and LSI Signals

Describes control unit composition, LSI signals, and their functions.

LSI Signal Details and LCD Interface

Further details on LSI signals, LCD interface, and power connections.

Absolute Humidity Sensor Circuit

Sensor Structure and Operational Principle

Explains the structure and operational principle of the absolute humidity sensor.

Sensor Detector Circuitry

Details the detector circuit for the absolute humidity sensor.

Touch Control Panel Servicing

Handling Electronic Components Safely

Precautions for handling sensitive electronic components like CMOS LSI.

Touch Control Panel Servicing Methods

Procedures for servicing the touch control panel with oven or external power.

Component Replacement and Adjustment Procedure

High Voltage and Wiring Safety Precautions

Warnings and precautions related to high voltage and wiring during component replacement.

Outer Case Removal and Initial Checks

Step-by-step guide for removing the oven's outer case and performing initial checks.

Component Replacement Procedures: Oven Cavity and HV Components

Oven Cavity and HV Component Removal

Procedures for removing the oven cavity, power transformer, and HV rectifier/capacitor.

Component Replacement Procedures: Magnetron, Lamp, and Fan Motor

Magnetron, Lamp, and Fan Motor Removal

Procedures for removing the magnetron, oven lamp, and fan motor.

Component Replacement Procedures: Power Unit and Turntable Motor

Power Unit and Turntable Motor Removal

Procedures for removing the power unit, turntable motor, and related connectors.

Component Replacement Procedures: Switches and Door

Switch Adjustment and Door Replacement

Procedures for adjusting door interlock switches and replacing the oven door.

Door Replacement and Sealer Film

Door Disassembly and Reinstallation Steps

Steps for disassembling and reinstalling the oven door assembly.

Sealer Film Application Procedure

Procedure for applying the sealer film to the door panel.

Individual Door Parts Removal

Door Panel, Latch, CPU, and Harness Removal

Procedures for removing individual door parts like panel, latch, CPU unit, and harness.

Pictorial Diagram

Overall Oven Wiring Diagram

Provides a visual representation of the oven's wiring connections for service.

Power Unit Circuit Diagram

CPU Unit Circuit Diagram

Printed Wiring Board of Power Unit

Parts List and Ordering Information

Replacement Parts Identification

Lists all replaceable parts with reference numbers, descriptions, and quantities.

Packing and Accessories Details

Details the packing materials and accessories included with the oven for shipping.

Detailed Parts List

Electric, Cabinet, and Power Unit Parts Listings

Continues the comprehensive list of replacement parts for various sections of the oven.

Parts Diagrams

Door and Miscellaneous Parts Illustrations

Illustrates the location and assembly of door components and miscellaneous parts.

Oven and Cabinet Parts Diagram

Door and Miscellaneous Parts Diagrams