SHARP R120DPSC, R-120DG, R-120DP, R-120DSC Service Manual

R-120DG
R-120DP
R-120DSC

SUPPLEMENTAL SERVICE MANUAL

S5012R120DPG/

MICROWAVE OVEN

ON DEFLBSQTY CHECK

MODEL

START/MINUTE LUS

STOP/CLEAR

R-120DG
R-120DP

R-120DSC

HALF PINT

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, contact 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..)

This is a supplemental Service Manual for Models R-120DG, R-120DP, R-120DSC. This model is

quite similar to base model R-120DW. Use this supplemental manual together with the Base Model Service Manual
(Refer No. is S3007R120DPW/) for complete operation, service information, 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

FOREWORD AND WARNING...............................................................................................................................2

PRODUCT DESCRIPTION....................................................................................................................................3

PICTORIAL DIAGRAM ..........................................................................................................................................4

PARTS LIST ..........................................................................................................................................................5

PACKING AND ACCESSORIES ...........................................................................................................................9

This document has been published to be used for after

SHARP CORPORATION

sales service only.
The contents are subject to change without notice.

R-120DG
R-120DP
R-120DSC

PRECAUTIONS TO BE OBSER VED BEFORE AND
DURING SER VICING TO A VOID POSSIBLE
EXPOSURE TO EXCESSIVE MICROW A VE
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) interlock operation, (2) proper door closing, (3)
seal and sealing surfaces (arcing, wear, and other damage), (4) damage to or loosening of hinges and
latches, (5) evidence of dropping or abuse.

(c) Before turning on microwave power for any service test or inspection within the microwave generating

compartments, check the magnetron, wave guide or transmission line, and cavity for proper alignment,
integrity, and connections.

(d) Any defective or misadjusted components in the interlock, monitor, door seal, and microwave

generation and transmission systems shall be repaired, replaced, or adjusted by procedures described
in this manual before the oven is released to the owner.

(e) A microwave leakage check to verify compliance with the Federal Performance Standard should be

performed on each oven prior to release to the owner.

BEFORE SERVICING

Before servicing an operative unit, perform a microwave emission check as per the Microwave
Measurement Procedure outlined in this service manual.
If microwave emissions level is in excess of the specified limit, contact SHARP ELECTRONICS
CORPORATION immediately @1-800-237-4277.

If the unit operates with the door open, service person should 1) tell the user not to operate the oven
and 2) contact SHARP ELECTRONICS CORPORATION and The Food and Drug Administration's
Center for Devices and Radiological Health immediately.

Service personnel should inform SHARP ELECTRONICS CORPORATION of any certified unit found
with emissions in excess of 4mW/cm2. The owner of the unit should be instructed not to use the unit
until the oven has been brought into compliance.

WARNING TO SERVICE PERSONNEL

R-120DG
R-120DP
R-120DSC

Microwave ovens contain circuitry capable of pro­ducing very high voltage and current, contact with
following parts

may result in a severe, possibly

fatal, electrical shock.
(Example)
High Voltage Capacitor, High Voltage Power Trans-

former, Magnetron, High Voltage Rectifier Assem­bly, High Voltage Harness etc..

Read the Service Manual carefully and follow all
instructions.

Before Servicing

1. Disconnect the power supply cord ¬, and then remove
outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

WARNING:RISK OF ELECTRIC SHOCK.

DISCHARGE THE HIGH-VOLTAGE
CAPACITOR BEFORE SERVICING.

Don't Touch !
Danger High Voltage

When the testing is completed,

1. Disconnect the power supply cord, and then remove
outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Reconnect the leads to the primary of the power
transformer.

5. Reinstall the outer case (cabinet).

6. Reconnect the power supply cord after the outer case is
installed.

7. Run the oven and check all functions.

The high-voltage capacitor remains charged about 60
seconds after the oven has been switched off. Wait for 60
seconds and then short-circuit the connection of the high­voltage capacitor (that is the connecting lead of the high­voltage rectifier) against the chassis with the use of an
insulated screwdriver.

Whenever troubleshooting is performed the power supply
must be disconnected. It may, in some cases, be necessary
to connect the power supply after the outer case has been
removed, in this event,

1. Disconnect the power supply cord, and then remove
outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect the leads to the primary of the power
transformer.

5. Ensure that the leads remain isolated from other
components and oven chassis by using insulation tape.

6. After that procedure, reconnect the power supply cord.

After repairing

1. Reconnect all leads removed from components during
testing.

2. Reinstall the outer case (cabinet).

3. Reconnect the power supply cord after the outer case is
installed.

4. Run the oven and check all functions.

Microwave ovens should not be run empty. To test for the
presence of microwave energy within a cavity, place a cup
of cold water on the oven turntable, close the door and set
the power to HIGH and set the microwave timer for two (2)
minutes. When the two minutes has elapsed (timer at zero)
carefully check that the water is now hot. If the water
remains cold carry out Before Servicing procedure and re­examine the connections to the component being tested.

When all service work is completed and the oven is fully
assembled, the microwave power output should be checked
and a microwave leakage test should be carried out.

1

R-120DG
R-120DP
R-120DSC

SERVICE MANUAL

MICROWAVE OVEN

R-120DG/ R-120DP/ R-120DSC

FOREWORD

This Manual has been prepared to provide Sharp Electronics Corp. Service Personnel with Operation and Service
Information for the SHARP MICROWAVE OVEN, R-120DG, R-120DP, R-120DSC.

The models R-120DG, R-120DP and R-120DSC are quite similar to base model R-120DW (Refer No. is S3007R120DPW/).
It is recommended that service personnel carefully study the entire text of this manual and the base model's 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 electrical shock and

microwave radiation hazard.

WARNING

Never operate the oven until the following points are ensured.
(A) The door is tightly closed.
(B) The door brackets and hinges are not defective.
(C) The door packing is not damaged.
(D) The door is not deformed or warped.
(E) There is no other visible damage with the oven.

Servicing and repair work must be carried out only by trained service personnel.

DANGER

Certain initial parts are intentionally not grounded and present a risk of electrical shock only during servicing.
Service personnel - Do not contact the following parts while the appliance is energized;
High Voltage Capacitor, Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage
Harness;
If provided, Vent Hood, Fan assembly, Cooling Fan Motor.

All the parts marked “*” on parts list are used at voltages more than 250V.
Removal of the outer wrap gives access to voltage above 250V.
All the parts marked “∆” on parts list may cause undue microwave exposure, by themselves, or when they are damaged,

loosened or removed.

SHARP ELECTRONICS CORPORATION

SHARP PLAZA, MAHWAH,

NEW JERSEY 07430-2135

2