R-28STM - Sharp Home Appliance Service Manual (repair manual)

Model
R-28STM
Pages
23
Size
4.21 MB
Type
PDF
Document
Service Manual
Brand
Device
Home Appliance / Microwave Oven
File
r-28stm.pdf
Date

View Sharp R-28STM Service Manual online

CHAPTER 1. SAFTY PRECAUTIONS
CHAPTER 2. CAUTIONS
CHAPTER 3. THE HEATING PRINCIPLE OF MICRO-
CHAPTER 4. INSTALLATIONS
CHAPTER 5. SCHEMATIC DIAGRAM
CHAPTER 6. CIRCUIT DESCRIPTION
CHAPTER 7. TOOLS AND MEASURING INSTRUMENTS
CHAPTER 8. MICROWAVE LEAAGE TEST
CHAPTER 9. MEASUREMENT OF MICROWAVE 
CHAPTER 10. TROUBLE SHOOTING PROCEDURES
CHAPTER 11.  
CHAPTER 12. IMPORTANT THINGS TO DO PRIOR
CHAPTER 13. SAFTY CHEC  S AND TESTS AFTER  
CHAPTER 14. 
Parts List
MICROWAVE OVEN
SERVICE MANUAL
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 interests of user-safety the oven should be restored to its
original condition and only parts identical to those specified
should be used.
R-28STM
WAVE
POWER OUTPUT
COMMON BREAKDOWN AND MEANS OF 
PREPARING
CRITICAL PART SERVICING
K
SERVING
EXPLODED VIEW
(800W 240V50Hz)
R-28STM
 
 
 
 
 
 
 
 
 
 
SAFETY PRECAUTIONS
 
 
This device is to be serviced only by properly qualified service personnel. 
Consult the service manual for proper service procedures to assure continued safety operation and for precautions to 
be taken to avoid possible exposure to excessive microwave energy. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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) 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 should be performed on each oven prior to release to the owner. 
CAUTION 
MICROWAVE RADIATION 
DO NOT BECOME EXPOSED TO RADIATION FROM THE MICROWAVE GENERATOR 
OR OTHER PARTS CONDUCTING MICROWAVE ENERGY. 
 
 
 
 
 
 
 
 
 
TABLE OF CONTENTS 
 
 
 
                                                                                                                                                (page) 
SAFETY PRECAUTIONS------------------------------------
---------------
------Inside front cover 
CAUTIONS------------------------------------------------------------------------------------------------1-1 
THE HEATING PRINCIPLE OF MICROWAVE--------------------------------------------------2-1 
INSTALLATIONS----------------------------------------------------------------------------------------3-1 
OPERATING INSTRUCTIONS----------------------------------------------------------------------4-1 
SCHEMATIC DIAGRAM--------------------------------------------------------------------------4-1 
CIRCUIT DESCRIPTION-------------------------------------------------------------------------4-2 
SERVICE INFORMATION-----------------------------------------------------------------------------5-1 
TOOLS AND MEASURING INSTRUMENTS------------------------------------------------5-1 
MICROWAVE LEAKAGE TEST----------------------------------------------------------------5-2 
MEASUREMENT OF MICROWAVE POWER OUTPUT---------------------------------5-3 
TROUBLE SHOOTING PROCEDURES------------------------------------------------------5-4 
COMMON BREAKDOWN AND MEANS OF REPAIRING-------------------------------5-8 
IMPORTANT THINGS TO DO PRIOR TO CRITICAL PART SERVICING-------------------------5-9 
SAFETY CHECKS AND TESTS AFTER SERVING--------------------------------------5-10 
EXPLODED VIEW---------------------------------------------------------------------------------------6-1 
REPLACEMENT PARTS LIST-----------------------------------------------------------------------6-1
 
 
 
 
 
 
 
 
 
 
CAUTIONS 
 
 
 
 
• DO NOT operate on a 2-wire extension cord during 
repair and use. 
• NEVER TOUCH any oven components or wiring during 
operation. 
• BEFORE TOUCHING any parts of the oven, always 
remove the power plug from the outlet.   
• For about 30 seconds after the oven stops, an electric 
charge remains in the high voltage capacitor. When 
replacing or checking, you must discharge the high 
voltage capacitor by shorting across the two terminals 
with an insulated screwdriver. 
 
 
 
• Remove your watches whenever working close to or 
replacing the Magnetron. 
• DO NOT touch any parts of the control panel circuit. A 
resulting static electric discharge may damage this 
P.C.B.  
• NEVER operate the oven with no load. 
• NEVER injure the door seal and front plate of the oven 
cavity. 
• NEVER put iron tools on the magnetron. 
• NEVER put anything into the latch hole and the 
interlock switches area.` 
 
 
 
 
 
 
 
Unlike other appliances, the microwave oven 
is 
high-voltage and high-current equipment. 
Though it is free from danger in ordinary use,
extreme care should be taken during repair. 
MICROWAVE RADIATION 
Personnel should not be exposed to the 
microwave energy which may radiate from the 
magnetron or other microwave generating 
device if it is improperly used or connection. 
All input and output microwave connections, 
waveguide, flange and gasket must be secure 
never operate the device without a microwave 
energy absorbing load attached. 
Never look into an open waveguide or antenna 
while the device is energized. 
• Proper operation of the microwave oven 
requires that 
the magnetron be assembled to the waveguide 
and 
cavity. Never operate the magnetron unless it is
properly installed.   
• Be sure that the magnetron gasket is 
properly 
installed around the dome of the tube 
whenever 
installing the magnetron. 
 
THE OVEN IS TO BE SERVICED 
ONLY 
BY PROPERLY QUALIFIED SERVICE
PERSONNEL.
 
1-1 

Download Sharp R-28STM Service Manual (Repair Manual)

Here you can view online and download Sharp R-28STM Service Manual in PDF. R-28STM service manual will guide through the process and help you recover, restore, fix, disassemble and repair Sharp R-28STM Microwave Oven. Information contained in service manuals typically includes schematics / circuit diagrams, wiring diagrams, block diagrams, printed wiring boards, exploded views, parts list, disassembly / assembly, pcb.