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PRELIMINARY

A.  SINCE NEARLY 2,100 VOLTS EXISTS IN SOME

CIRCUITS OF THIS UNIT REPAIRS SHOULD BE
CARRIED OUT WITH GREAT CARE.
The filament leads of magnetron carry High
Voltage with respect to ground. Extreme caution 
must be exercised. Never plug the unit into a
power source to determine which component is
defective in high voltage section.

B.  TO AVOID POSSIBLE EXPOSURE TO

MICROWAVE ENERGY LEAKAGE, THE
FOLLOWING PRECAUTIONS MUST BE TAKEN
BEFORE SERVICING.

(1)  Before the power is applied:

(a)  Make sure the primary interlock switch, the

secondary interlock switch and the interlock
monitor switch operate properly by opening
and closing the door several by opening and
closing the door several times. 

(b)  Make sure the perforated screen and the 

dielectric choke of the door are correctly and
firmly mounted.

(2)  After power is applied:

(a)  Make sure the interlock switch mechanism 

is operating properly by opening and closing
the door.

(b)  Check microwave energy leakage must bebelow 

the limit of 5  mW/cm

2.

(All service adjustments should be made for

minimum microwave energy leakage 

readings).

(3)  Do not operate the unit until it is completely

repaired, if any of the following conditions exist.
The unit must not be operated.

(a)  The door does not close firmly.
(b)  The hinge is broken.
(c)  The door seal is damaged.
(d)  The door is bent or warped, or there is any

other visible damage on the unit that may
cause microwave energy leakage.

NOTE:  Always keep the seal clean.
(e)  Make sure that there are no defective parts 

in the interlock mechanism.

(f)   Make sure that there are no detective parts

in the microwave generating and transmission
assembly (especially waveguide).

(4)  The following items should be checked after  the

unit is repaired:

(a)  The interlock monitor switch is connected

correctly and firmly.

(b)  The magnetron gasket is properly positioned 

and mounted.

(c)  The waveguide and the oven cavity are intact. 

(no microwave energy leakage)

(d)  The door can be properly closed and the

safety switches work properly.

(e)  The unit must stop when the door is opened or

the time is up.

The unit must not be operated with any of the above
components removed or by-passed.

7-1

PRECAUTIONS AND REPAIR SERVICE TIPS

SERVICE INFORMATION

Содержание 721.63652300

Страница 1: ...22 BASIC FIELD MANUAL FOR MICROWAVE OVEN MODEL 721 63652300 721 63652301 721 63659300 721 63659301 721 63654300 721 63654301 721 63653300 721 63653301 June 2005 MODEL 721 63652 721 63659 721 63654 72...

Страница 2: ...lignment 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...

Страница 3: ...S FEATURES 6 1 SERVICE INFORMATION 7 1 PRECAUTIONS AND REPAIR SERVICE TIPS 7 1 MICROWAVE LEAKAGE TEST 7 2 POWER OUTPUT MEASUREMENT 7 3 DISASSEMBLY INSTRUCTIONS 7 4 INTERLOCK SYSTEM 7 12 INTERLOCK CONT...

Страница 4: ...y Thermostat Open at 110 C 5 C Fuse 20A Primary Interlock Switch Secondary Interlock Switch Interlock Monitor Magnetron 2M248 High Voltage Capacitor Capacitor 1 0 F 2 1 KV AC High Voltage Diode Diode...

Страница 5: ...rea 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 g...

Страница 6: ...at all times In the event of an electrical short circuit grounding reduces the risk of electrical shock The plug must be plugged into an outlet that is properly installed and grounded BEFORE YOU BEGI...

Страница 7: ...CONTROL PANEL 4 1 OPERATING INSTRUCTIONS 1 2 5 8 11 14 17 18 20 23 26 29 4 7 10 13 16 19 22 25 28 31 12 24 30 6 3 9 15 21 27...

Страница 8: ...time or power 16 Hold Warm Touch this pad to keep hot cooked foods safely warm in your oven for up to 99 minutes 99 seconds Hold Warm can be used by itself or it can automatically follow a cooking cyc...

Страница 9: ...5 1 OVERALL CIRCUIT DIAGRAM SCHEMATIC DIAGRAM I Check the Model No...

Страница 10: ...5 2 SCHEMATIC DIAGRAM II Check the Model No ADD Noise filter...

Страница 11: ...Cook STOP Clear VENT On Off Frozen Vegetable Vegetable Fresh Auto Reheat Auto VENT 5 Speed Frozen Entree Potato High Night Off LIGHT Favorite Recipe Hold 1 2 3 4 Less Clock More 8 9 0 Canned Vegetable...

Страница 12: ...light comes on The unit will begin cooking and the display window will show the time counting down by seconds D After about 5 minutes make sure the primary interlock switch the secondary interlock sw...

Страница 13: ...ll service adjustments should be made for minimum microwave energy leakage readings 3 Do not operate the unit until it is completely repaired if any of the following conditions exist The unit must not...

Страница 14: ...for microwave leakage after every servicing The power density of the microwave radiation leakage emitted by the microwave oven should not exceed 4 mW cm2 Always start measuring of an unknown field to...

Страница 15: ...leakage not be more than 2 mW cm2 after determining that all parts are in good condition functioning properly and genuine replacement parts which are listed in this manual have been used 3 At least on...

Страница 16: ...ove a screw securing the control panel assembly to the oven cavity 2 Remove the control panel with pushing it upward 3 Remove the connectors CN1 and sensor CN5 wire leads RY2 CN2 CN4 from the circuit...

Страница 17: ...F P C connector into the terminal socket securely with the fingers 2 Hold the plastic fastener with thumb and forefinger of the other hand and push it slowly into the terminal socket Figure 6 NOTE Whe...

Страница 18: ...g the screws 1 or 2 screws securing it to the out case 4 Remove two screws on the left central edge and one screws on the right central edge of Base plate Remove the Mount All from the out case by rem...

Страница 19: ...WH from cooktop lamp Secondary Interlock Switch Monitor Interlock Switch Primary Interlock Switch PK from P C B BL from P C B WH from H V Transformer RD from H V Transformer 7 7 C REMOVING THE DOOR IN...

Страница 20: ...AREFULLY NOTES When removing the magnetron make sure that its dome does not hit any adjacent parts or it may be damaged When replacing the magnetron be sure to install the magnetron gasket in the corr...

Страница 21: ...that the primary interlock switch the secondary interlock switch and the interlock monitor switch is in good operating normally After replacing the door check for microwave energy leakage with a surv...

Страница 22: ...e by loosening mounting plate screws 1 or 2 screws securing it to the back plate See Figure 18 2 Remove MOUNT ALL loosening one screw loosening one screw securing the ventilation Motor and back plate...

Страница 23: ...ws securing it to the oven cavity Figure 21 4 Disconnect the leadwire from the turntable motor terminals 5 Remove the 2 screws securing the turntable motor to the oven cavity ASS Y Figure 22 NOTES Rem...

Страница 24: ...ustment of the latch board may not be necessary Go to Steps 5 and 6 to check the sequence of the switches NOTE To correct sequence of the Primary Interlock Switch Secondary Interlock Switch and the In...

Страница 25: ...o to the body of the switches in the following sequence Interlock Monitor Switch Primary Interlock Switch Secondary Interlock Switch NOTE The Interlock Monitor Switch is an added safety check on the P...

Страница 26: ...the secondary switch operation is abnormal make the necessary adjustment or replace the switch only with the same type of switch C MONITOR SWITCH TEST Disconnect the wire lead from the monitor switch...

Страница 27: ...each filament terminal of the magnetron and the chassis ground with an ohm mater on high test scale 1 Measure the resistance With an ohm meter on Rx1 scale a Primary winding b Filament winding c Secon...

Страница 28: ...inuity 1 Forward Ohm meter Figure 26 a 1 Reverse Ohm meter Figure 26 b Normal reading Momentarily indicates several ohms and then gradually returns to infinite ohms Abnormal reading Indicates continui...

Страница 29: ...EDURES RESULTS TOUCH KEY BOARD SENSOR Resistance value When When not touched touched Less than More than 400 ohms 1 mega ohm 1 2 3 4 5 6 7 8 9 10 11 12 13 FPC CONNECTOR Top Normal Approximately BK RD...

Страница 30: ...switches and or the interlock monitor switch Malfunction of the high voltage transformer the high voltage capacitor including the diode the magnetron the blower motor or the circuit board PROBLEMS CAU...

Страница 31: ...l operate GOOD Replace the circuit board Replace RELAY1 PROBLEM B FAN motor and oven lamp turn on When the door is closed and START key is touched Measure the voltage at pin NO 35 of U01 Voltage readi...

Страница 32: ...e interlock switches the door sensing and the relay check good 2 The unit with a normal relay continuously operates 3 Proper temperature measurement is not obtained 4 The buzzer does not sound or cont...

Страница 33: ...ERATION on page 6 1 DISPLAY Problems A thru C HELP UP Problems D thru E BUZZER Problems F Measure voltage between pin 1 and pin 3 of connector CN1 Measure resistance of touch key board after removing...

Страница 34: ...connector S1 Contact OK Replace Circuit board Correct seating Normal circuit board Normal contact Poor contact Normal Primary switch No continuity Adjust or replace door sensing switch Measure resista...

Страница 35: ...H V C Abnormal Replace H V D Normal Magnetron Replace Magnetron Normal Normal H V D Check the continuity of H V D see page 7 16 Replace H V C Normal resistance Replace H V T Normal resistance NO conti...

Страница 36: ...7 24 PROBLEM F No buzzing when touching the key between stages or at end of cooking 1 Normal circuit board Check normal operation circuit board Replace circuit board Runs...

Страница 37: ...magnetron thermal fuse and oven thermostat Poor contact Replace circuit board Normal circuit board Contact OK Normal contact Correct seating Check contact of connector S1 see page 7 4 Replace ventila...

Страница 38: ...EW DOOR PARTS Model 721 63652300 721 63652301 721 63659300 721 63659301 721 63654300 721 63654301 721 63653300 721 63653301 8 1 1009 1003 1381 1011 1000 1002 1005 1004 1006 1007 W109 1008 For Model 72...

Страница 39: ...8 2 CONTROLLER PARTS 07 2381 2008 2006 W106 2004 2002 2000 07 2381 2008 2006 W106 2004 EV For Model 721 63652 721 63659 721 63654 For Model 721 63653...

Страница 40: ...1 W121 6001 3043 3014 3032 3018 3036 W121 5036 3026 3028 5038 6000 3033 W121 W108 3010 3031 W109 W138 W142 W138 W142 For Model 721 63653 721 63659 For Model 721 63652 721 63654 For Model 721 63653 721...

Страница 41: ...8 4 LATCH BOARD PARTS 4001 W111 4000 4002 4003 4002 4004 EV...

Страница 42: ...8 5 INTERIOR PARTS I 3002 3012 3008 3034 5044 3004 W105 W101 5018 5000 W108 W101 5002 5009 5049 5008 W101 W101 5035 W108 3009 5019 5058 5043 5024 EV...

Страница 43: ...45 5038 5022 3027 W146 5012 5006 5010 5007 5017 5014 5001 W105 Check the Model No Check the Model No Check the rating label of Model and order SVC parts according to the Model No 8 6 INTERIOR PARTS II...

Страница 44: ...5 5038 5022 3027 W146 5012 5006 5010 5007 5041 5014 5001 W105 Check the Model No Check the Model No 8 7 Check the rating label of Model and order SVC parts according to the Model No INTERIOR PARTS II...

Страница 45: ...8 8 INSTALLATION PARTS 6008 6010 6011 6009 VINYL BAG EV...

Страница 46: ...P NO 3828W5S4598 Printed in Korea...

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