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SERVICE INFORMATION 

TOOLS AND MEASURING INSTRUMENTS

 

NECESSARY TOOLS 

Tools normally used for TV servicing are sufficient. 

Standard tools are listed below. 

• Diagonal pliers 

• Long nose pliers 

• Phillips screwdriver 

• Flat blade screwdriver 

• Wrench (size 5mm) 

• Nutdriver (size 5mm) 

• Adjustable wrench 

• Soldering iron 

• Solder 

• Vinyl insulation tape 

• Polishing cloth 

 

 

MICROWAVE LEAKAGE TEST

 

CAUTIONS 

• Be sure to check microwave leakage prior to 
servicing the oven if the oven is operative prior to 
servicing. 
• The service personnel should inform the 
manufacture importer, or assembler of any certified 
oven unit found to have a microwave emission 
level in excess of 5 mW/cm

2

 

and should repair any 

unit found to have excessive emission levels at no cost 

to the owner and should ascertain the cause of the 

excessive leakage. The service personnel should 

instruct the owner not to use the unit until the oven has 

been brought into compliance. 

• If the oven operates with the door open, the service 
personnel should: 
- Tell the user not to operate the oven. 
- Contact the manufacturer. 

• The service personnel should check all surface and 

vent openings for microwave leakage. 

• Check for microwave leakage after every servicing. The 

power density of the microwave radiation leakage 

emitted by the microwave oven should not exceed 

5 mW/cm

2

. Always start measuring of an unknown field 

to assure safety for operating personnel from radiation 

leakage. 

 

NECESSARY MEASURING 
INSTRUMENTS 

• TESTER(VOLTS-DC, AC., Ohmmeter) 

• Microwave survey meter 

- Holaday HI-1710(A) 

- Narda 8100 

8200 

• Inch scale 

• 600 cc non conductive material beaker (glass or 

plastic), inside diameter: approx. 8.5 cm(3

1/2 

in.) 

• Cylindrical and made of borosilicate glass vessel. 

max. thickness: 3 mm 

outside diameter: approx. 190mm 

height: approx. 90mm 

• Glass thermometer: 100°C or 212°F (1 deg scale)

 

MEASURING MICROWAVE ENERGY 
LEAKAGE 

• Pour 275±15 cc of 20±5°C(68±9°F) water in a 
beaker 
which is graduated to 600 cc, and place the beaker 
on the center of the turntable. 
• Set the energy leakage monitor to 2,450 MHz and 
use it following the manufacturer's recommended 
test procedure to assure correct result. 
• When measuring the leakage, always use the 2-
inch (5 cm) spacer supplied with the probe. 
• Operate the oven at its maximum output. 
• Measure the microwave radiation using and 
electromagnetic radiation monitor by holding the 
probe perpendicular to the surface being measured 
Move probe along shaded area 
Probe scanning speed: Less than 2.5 cm/sec 

 

5-1 

Summary of Contents for R-662

Page 1: ... 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 use...

Page 2: ...or 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 misadjus...

Page 3: ...AM 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 IMPORTANTTHINGSTODOPRIORTOCRITICALPARTSERVICING 5 9 SAFETY CHECKS AND TESTS AFTER SERVING 5 10 EXPLODED VIEW 6 1 REPLACEMENT PARTS LIST 6 1 ...

Page 4: ...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 conn...

Page 5: ...gth among the molecule and changed to microscopic microwave heating Microwave heating not only concerned the nature of the matter itself but also closely connected with the electric field strength and frequency When the frequency is low the molecule swaying rate and the acute degree of the mutual friction among the molecule is low and would produce much heat When the frequency is too high as the s...

Page 6: ... and flat surface at least 10 cm 4 inches from the wall 7 Place the microwave oven as far away as possible from TV RADIO COMPUTER etc to prevent interference BEFORE YOU BEGIN READ THE FOLLOWING INSTRUCTIONS COMPLETELY EARTHING INSTRUCTIONS This microwave oven is designed to be used in a fully earthed condition It is imperative therefore to make sure it is properly earthed before servicing WARNING ...

Page 7: ...SCHEMATIC DIAGRAM ...

Page 8: ...ir is also directed into the oven to exhaust the vapor in the oven through the upper plate Timer starts rotating 3 2 volts AC is generated from the filament winding of the high voltage transformer This 3 2 volts is applied to the magnetron to heat the magnetron filament through two noise preventing choke coils A high voltage of approximately 2100 volts AC is generated in the secondary of the high ...

Page 9: ...microwave leakage Check for microwave leakage after every servicing The power density of the microwave radiation leakage emitted by the microwave oven should not exceed 5 mW cm2 Always start measuring of an unknown field to assure safety for operating personnel from radiation leakage NECESSARY MEASURING INSTRUMENTS TESTER VOLTS DC AC Ohmmeter Microwave survey meter Holaday HI 1710 A Narda 8100 820...

Page 10: ...an 1 inch sec 2 5 cm sec along the shaded area otherwise a false reading may result The test probe must be held with the grip portion of the handle A false reading may result if the operator s hand is between the handle and the probe When testing near a corner of the door keep the probe perpendicular to the surface making sure the probe horizontally along the oven surface this may possibly cause p...

Page 11: ...d on the center of the turntable which is in the lowest position and the microwave power switched on The time T for the temperature of the water to rise by a value T of 10 2 K is measured where T is the time in seconds and T is the temperature rise The initial and final water temperatures are selected so that the maximum difference between the final water temperature and the ambient temperature is...

Page 12: ...nce Measure the insulating resistance with a multi meter or a mega ohmmeter The value should not less than 2 mega ohm Otherwise part examination should be taken at once Such as checking whether the motor the thermal cutout the transformer or the capacitor are electricity leaking 2 Examination of the resistance value of the microwave oven Close the door set the time the oven is at operating conditi...

Page 13: ...citor pole and the cabinet FIG 5 6 should be checked If the resistance value between the capacitor pole and the cabinet is the capacitor is normal Then check the earth of the magnetron s two filament to see whether they are short circuited FIG 5 7 If they are short circuited and the filament strikes the shell of the magnetron it indicates the magnetron has broken and should be replaced by a new sa...

Page 14: ...st the upper screw Loosen out the screw push the door close to the oven to hook the door hook with the plastic parts then tighten the screw again If the leakage is larger at the right below then adjust the lower screw Loosen the screw push the door close to the oven to hook the door hook with the switch holder tightly then tighten the screw again and open and close the door repeatedly to check whe...

Page 15: ...l cutout is playing its protective role and you should check whether the fan is working in normal Turn off the oven pull out the power plug take down the outer case discharge the capacitor then turn the fan with hand to see whether it is moving flexibly If not it indicates that the oil bearing of the fan motor has run off the oil and should take down the fan combination to repair the motor Loosen ...

Page 16: ... Turntable Motor Wire leads removed Measure the resistance Ohm meter scale R 1000 Normal Approx 3 2kΩ Abnormal or Several Ω NOTE z A MICROWAVE LEAKGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS SERVICED FOR ANY REASON z MAKE SURE THE WIRE LEADS ARE IN THE CORRECT POSITION z WHEN REMOVING THE WIRE LEADS FROM THE PARTS BE SURE TO GRASP THE CONNECTOR NOT THE WIRES 5 8 ...

Page 17: ...2 Insert the plug securely 3 Change the weave 5 The oven can heat within 2 3 minutes but can not heat from the fourth minutes 1 The winding of the fan motor in open circuited 2 The fan falls off 3 The plug of the fan motor falls off 4 The turntable shaft is griped with the motor bearing 5 The cooling vent blocked 1 Change the fan motor 2 Change the fan 3 Insert the plug 4 Overhauling them 5 Repair...

Page 18: ...eck the electrical continuity 2 2 Make sure the power cord is pulled out and the high voltage capacitor is discharged before the electrical continuity check 2 3 Set the ohmmeter to Low Resistance range and connect both leads alligator clips to the switch terminals 2 4 Open the door and notice the meter reading The primary or secondary interlock switch should show an infinite resistance when the do...

Page 19: ...1 3 Check the following items before turning the oven ON 1 Proper door closing seal choke surfaces and hinges 2 No outer case damage 3 Proper interlock and monitor operations Insulation Resistance Test If the low voltage power supply has been repaired use a 500 V Mega ohmmeter to measure the resistance between the primary Line and Neutral of the power plug and operator accessible metal parts The r...

Page 20: ...ECO MEMBRAN R 662 ...

Page 21: ... S17 Screw Ф4 12 Screw Ф3 10 1 1 2 1 A 01 3 28 A 00 Z24 B 01 Cover Wave Guide Cavity Assembly Case Out Base Plate 1 1 1 B 03 BRKT Hinge U E 01 Magnetron E 06 E 05 E 07 E 11 E 10 E 13 H V Diode H V Capacitor H V Transformer Filter Noise Fuse Lamp 1 1 1 1 1 1 1 L 01 L 07 Board Latch ASS Y H V Fuse Lever Switch 2 1 1 1 ASS Y DOOR ASS Y C PANEL C 00 D 00 1 1 W 04 Guide Wind 1 1 E 28 Power Cord ASS Y 1...

Page 22: ...ASS Y 1 EGXEEXU 01 K C18 261400124800 PCB ASS Y 1 EGXEEXU 01 K C26 261400209140 SWITCH CIRCUIT 1 C55 261515901200 SHIELD 1 SGCC T 0 5 D00 ASS Y DOOR 1 After assembly D01 261500201000 ASS Y DOOR FRAME 1 C17L SPCC T 0 5 D02 261300500903 LATCH 1 C17L D02 261300500903 LATCH 1 C17L D03 252010000388 SPRING LATCH 1 D04 251502401215 ASS Y BRKT HINGE T 1 C17L SPCC T 1 5 D05 262200400004 BARRIER SCREEN I 1 ...

Page 23: ...A 250V L05 261202804612 HARNESS MAIN 1 EG820C PM0E H1 T01 251200300001 MOTOR TRAY 1 TYJ50 8A7 220 240V T02 252200100008 COUPLER 1 C23L PPS T02 252200100008 COUPLER 1 C23L PPS T03 262200200024 RING ROTATING ASS Y 1 M20L SPS T04 262100500004 TRAY 1 C17L diameterΦ255 W01 W02 W03 ASS Y FAN 1 After assembly W01 261300800501 GUIDE FAN 1 M20L FR W02 261300900102 FAN 1 C17L FR W02 261300900102 FAN 1 C17L ...

Page 24: ... 01 K C26 261400209140 SWITCH CIRCUIT 1 C55 261515901200 SHIELD 1 SGCC T 0 5 D00 ASS Y DOOR 1 After assembly D01 261500201000 ASS Y DOOR FRAME 1 C17L SPCC T 0 5 D02 261300500903 LATCH 1 C17L D02 261300500903 LATCH 1 C17L D03 252010000388 SPRING LATCH 1 D04 251502401215 ASS Y BRKT HINGE T 1 C17L SPCC T 1 5 D05 262200400004 BARRIER SCREEN I 1 C17L PET D06 262100402835 BARRIER SCREEN O 1 D07 26130014...

Page 25: ... 250V L05 261202804612 HARNESS MAIN 1 EG820C PM0E H1 T01 251200300001 MOTOR TRAY 1 TYJ50 8A7 220 240V T02 252200100008 COUPLER 1 C23L PPS T02 252200100008 COUPLER 1 C23L PPS T03 262200200024 RING ROTATING ASS Y 1 M20L SPS T04 262100500004 TRAY 1 C17L diameterΦ255 W01 W0 2 W03 ASS Y FAN 1 After assembly W01 261300800501 GUIDE FAN 1 M20L FR W02 261300900102 FAN 1 C17L FR W02 261300900102 FAN 1 C17L ...

Page 26: ...U 01 K C26 261400209140 SWITCH CIRCUIT 1 C55 261515901200 SHIELD 1 SGCC T 0 5 D00 ASS Y DOOR 1 After assembly D01 261500201000 ASS Y DOOR FRAME 1 C17L SPCC T 0 5 D02 261300500903 LATCH 1 C17L D02 261300500903 LATCH 1 C17L D03 252010000388 SPRING LATCH 1 D04 251502401215 ASS Y BRKT HINGE T 1 C17L SPCC T 1 5 D05 262200400004 BARRIER SCREEN I 1 C17L PET D06 262100402835 BARRIER SCREEN O 1 D07 2613001...

Page 27: ... 261202804612 HARNESS MAIN 1 EG820C PM0E H1 T01 251200300001 MOTOR TRAY 1 TYJ50 8A7 220 240V T02 252200100008 COUPLER 1 C23L PPS T02 252200100008 COUPLER 1 C23L PPS T03 262200200024 RING ROTATING ASS Y 1 M20L SPS T04 262100500004 TRAY 1 C17L diameterΦ255 ASS Y FAN 1 After assembly W01 261300800501 GUIDE FAN 1 M20L FR W02 261300900102 FAN 1 C17L FR W03 261200600620 MOTOR FAN 1 220 240V W04 26155750...

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