Magic Chef Mcb770b, Mcb770w, Mcb780w Owner's Manual

S/M No. : R631G0A003

MCB780W MCB780B

MCB770W MCD770B

Service Manual

Microwave Oven

Model: KOR-631G0A

KOR-631H0A KOR-631G9A KOR-631H9A

KOR-861G0A KOR-861H0A

DAEWOO ELECTRONICS CO., LTD.

PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWA 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 micro-

wave 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.

erating 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 per-

formed on each oven prior to release to the owner.

T ABLE OF CONTENTS

SAFETY AND PRECAUTIONS...........................................................................................................................................2

FOR SAFE OPERATION ......................................................................................................................................2

FOR SAFE SERVICE PROCEDURES .................................................................................................................2

SPECIFICATIONS...............................................................................................................................................................3

EXTERNAL VIEW................................................................................................................................................................4

OUTER DIMENSION.............................................................................................................................................4

FEATURE DIAGRAM............................................................................................................................................5

CONTROL PANEL................................................................................................................................................6

INSTALLATION...................................................................................................................................................................8

OPERATIONS AND FUNCTIONS.......................................................................................................................................9

DISASSEMBLY AND ASSEMBLY....................................................................................................................................10

INTERLOCK MECHANISM AND ADJUSTMENT.............................................................................................................17

TROUBLE SHOOTING GUIDE .........................................................................................................................................18

MEASUREMENT AND TEST............................................................................................................................................22

MEASUREMENT OF THE MICROWAVE POWER OUTPUT ............................................................................22

MICROWAVE RADIATION TEST.......................................................................................................................23

COMPONENT TEST PROCEDURE...................................................................................................................24

WIRING DIAGRAM............................................................................................................................................................25

PRINTED CIRCUIT BOARD..............................................................................................................................................26

CIRCUIT CHECK PROCEDURE ........................................................................................................................26

PCB CIRCUIT DIAGRAM....................................................................................................................................29

P.C.B. LOCATION NO ........................................................................................................................................30

EXPLODED VIEW AND PARTS LIST...............................................................................................................................32

DOOR ASSEMBLY .............................................................................................................................................32

CONTROL PANEL ASSEMBLY..........................................................................................................................32

TOTAL ASSEMBLY.............................................................................................................................................32

SAFETY AND PRECAUTIONS

1. FOR SAFE OPERATION

Damage that allows the microwave energy (that cooks or heats the food) to escape will result in poor cooking and may cause serious bodily injury to the operator. IF ANY OF THE FOLLOWING CONDITIONS EXIST, OPERATOR MUST NOT USE THE APPLIANCE. (Only a trained service personnel should make repairs.)

(1) A broken door hinge. (2) A broken door viewing screen. (3) A broken front panel, oven cavity. (4) A loosened door lock.

(5) A broken door lock. The door gasket plate and oven cavity surface should be kept clean. No grease, soil or spatter should be allowed to build up on these surfaces or inside the oven. DO NOT ATTEMPT TO OPERATE THIS APPLIANCE WITH THE DOOR OPEN. The microwave oven has concealed switches to make sure the power is turned off when the door is opened. Do not attempt to defeat them. DO NOT ATTEMPT TO SERVICE THIS APPLIANCE UNTIL YOU HAVE READ THIS SERVICE MANUAL.

2. FOR SAFE SERVICE PROCEDURES

1. If the oven is operative prior to servicing, a microwave emission check should be performed prior to servicing the

oven.

2. If any certified oven unit is found to servicing, a microwave emission check should be performed prior to servicing the

oven.

(a) inform the manufacturer, importer or assembler,

(b) repair the unit at no cost to the owner,

(d) tell the owner of the unit not to use the unit until the oven has been brought into compliance.

3. If the oven operates with the door open, the service person should tell the user not to operate the oven and contact

the manufacturer and CDRH immediately.

CAUTION

This device is to be Serviced only by Properly Qualified Service Personel. 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.

CAUTION

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 CONNECTED. ALL INPUT AND OUTPUT MICROWAVE CONNECTIONS. WAVEGUIDE FLANGES AND PASKETS MUST BE SECURE. NEVER OPERATE THE DEVICE WITHOUT A MICROWAVE ENERGY ABSORBING LOAD ATTACHED. NEVER LOOK INTO AN OPEN SAVEGUIDE OR ANTENNA WHILE THE DEVICE IS ENERGIZED.

MODEL KOR-631G/H KOR-631G/H9A KOR-861G/H POWER SUPPLY 120V~60Hz, SINGLE PHASE WITH GROUNDING

POWER

MICROWAVE 1200W 1000W 1000W

CONSUMPTION

GRILL

COMBINATION MICROWAVE ENERGY OUTPUT 800W 700W 900W MICROWAVE FREQUENCY 2450MHz OUTSIDE DIMENSIONS (W X H X D) 465x279x360 mm (18.3x11.0x14.2 in)

495x294x388 mm (19.5x11.6x15.3 in)

CAVITY DIMENSIONS (W X H X D) 290x211x306 mm (11.4x8.3x12.0 in)

320x228x388 mm (12.6x9.0 x 13.3 in) NET WEIGHT Approx. 13 kg (28.66 Ibs.) Approx. 14 kg (30.9 Ibs.) TIMER 59 min. 99 sec. FUNCTION SELECTIONS MICROWAVE POWER SELECTIONS 10 LEVELS CAVITY VOLUME 0.7 Cu. Ft. 0.9 Cu. Ft.

* SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE.

SPECIFICATIONS

EXTERNAL VIEW

1. OUTER DIMENSION(KOR-631G/H, 631G/H9/KOR-861G/H)

465/495

279/294

360/388

279/294

1. DOOR SEAL

Door seal maintains the microwave within the oven cavity and prevents microwave leakage.

2. DOOR HOOK

When the door is closed, it will automatically lock shut. If door is opened while oven is operating, magnetron tube will immediately stop operating.

3. DOOR SCREEN

Allows viewing of food. Microwave cannot pass through perforations in screen.

4. SPATTRSHIELD

Protects the microwave outlet from splashes of cooking foods.

5. OVEN LAMP

Automatically turns on during oven operating.

6. SAFETY INTERLOCK SYSTEM

7. CONTROL PANEL

8. GLASS COOKING TRAY

Made of special heat resistant glass. The tray must always be in proper position before operating. Do not cook food directly on the tray.

9. OVEN FRONT PLATE

10. DOOR OPENING BUTTON

To open the door push the door opening button. When door is closed, it will automatically lock shut. If door is opened while oven is operating, magnetron tube will immediately stop operating.

11. ROLLER GUIDE

Supports the glass cooling tray.

2. FEATURE DIAGRAM

1. Time set pad – Used to set the cooking time and the present time.

2. Display – Cooking time, power level, indicators and present time are displayed.

3. One touch – Used to cook or reheat specific quantities of food.

4. Auto cook – Used to cook or reheat.

5. More – Used to add time to cooking.

6. Less – Used to remove time from cooking.

7. Auto Defrost – Used to defrost foods. (for weight)

8. Power – Used to set power level.

9. Defrost – Used to defrost foods. (for time)

10. Kitchen Timer – Used as minute timer, delay cooking, hold setting after cooking.

11. Clock – Used to set clock.

12. Stop/Clear – Used to stop the oven operation or to delete the cooking data.

13. Start/Speedy cook – Used to start the oven and also used to set a reheat time.

3. CONTROL PANEL

1) KOR-631G0A/631G9A

2) KOR-861G0A

1. Time set pad – Used to set the cooking time and the present time.

2. Display – Cooking time, power level, indicators and present time are displayed.

3. One touch – Used to cook or reheat specific quantities of food.

4. More – Used to add time to cooking.

5. Less – Used to remove time from cooking.

6. Auto Defrost – Used to defrost foods. (for weight)

7. Power – Used to set power level.

8. Defrost – Used to defrost foods. (for time)

9. Kitchen Timer – Used as minute timer, delay cooking, hold setting after cooking.

10. Clock – Used to set clock.

11. Stop/Clear – Used to stop the oven operation or to delete the cooking data.

12. Start/Speedy cook – Used to start the oven and also used to set a reheat time.

3. CONTROL PANEL

1) KOR-631H0A/631H9A/861H0A

INSTALLATION

1. Steady, flat location.

This microwave oven should be set on a steady, flat surface.

2.Leave space behind and side.

All air vents should be kept a clearance. If all vents are covered during operation, the oven may be overheated and, eventually, cause oven failure.

3.Away from radio, and TV sets

Poor television reception and radio interference may result if the oven is located close to a TV, radio, antenna, or feeder and so on.

4.Away from heating appliances and water taps

Keep the oven away from hot air, steam or splash when choosing a place to position it, or the insulation might be adversely affected and breakdowns occur.

5.Power supply

• Check your local power source. This microwave oven requires a current of approximately 12/10(KOR-630A9A) amperes, 120Volts, 60Hz grounded outlet.

• Power supply cord is about 0.8 meters long.

1. A short power-supply cord is provided to reduce the risks resulting from becoming entangled in or tripping over

a longer cord.

2. Longer cord sets or extension cords are available and may be used if care is exercised in their use.

3. If a long cord or extension cord is used:

1) The marked electrical rating of the cord set or extension cord should be at least as great as the electrical rating of the appliance.

2) The extension cord must be a grounding type 3-wire cord.

3) The longer cord should be arranged so that it will not drape over the counter top or tabletop where it can be pulled on by children or tripped over unintentionally.

6. Examine the oven after unpacking for any damage such as:

A misaligned door, broken door or a dent in cavity. If any of the above are visible, DO NOT INSTALL, and notify dealer immediately.

OPERATIONS AND FUNCTIONS

1. Connect the main lead to an electrical outlet.

2. After placing the food in a suitable container, open the oven door and put it on the glass tray. The glass tray must always be in place during cooking.

3. Close the door securely.

4. When the oven door is opened, the light turns off.

5. The oven door can be opened at any time during operation by touching the door release button on the control panel. The oven will automatically shut off. To restart the oven, close the door and then touch START.

6. Each time a button is touched, a BEEP will sound to acknowledge the touch.

7. The oven automatically cook on full power unless set to a lower power level.

8. The display will show : 0 when the oven is plugged in.

9. Time clock returns to the present time when the cooking time ends.

10.When the STOP/CLEAR pad is touched during the oven operatiion, the oven stops cooking and all information retained.

To erase all information (except the present time), touch the STOP/SLEAR pad once more. If the oven door is opened during the oven operation, all information is retained.

11. If the START pad is touched and the oven does not operate, check the area between the door and door is closed

securely. The oven will not start cooking under the door is completely closed or the program has been reset.

Wattage output chart

The power level is set by pressing the POWER pad. The chart shows the display, the power level and the percentage of power.

Make sure the oven is properly installed and plugged into the electrical.

Touch POWER pad Power level(Display) Approximate Percentage of Power

Once P-HI 100%

Twice P-90 90% 3 times P-80 80% 4 times P-70 70% 5 times P-60 60% 6 times P-50 50% 7 times P-40 40% 8 times P-30 30% 9 times P-20 20%

10 times P-10 10% 11 times P-00 0%

DISASSEMBLY AND ASSEMBL Y

Cautions to be observed when trouble shooting.

Unlike many other appliances, the microwave oven is high-voltage, high-current equipment. It is completely safe during normal operation. However, carelessness in servicing the oven can result in an electric shock or possible danger from a short circuit. You are asked to observe the following precautions carefully.

1. Always remove the power plug from the outlet before servicing.

2. Use an insulated screwdriver and ware rubber gloves when servicing the high voltage side.

3. Discharge the high voltage capacitor before touching any oven components or wiring.

(1) Check the grounding.

Do not operate on a two-wire extension cord. The microwave oven is designed to be used while earthed. It is imperative, therefore, to make sure it is earthed properly before beginning repair work.

(2) Warning about the electric charge in the high voltage capacitor.

For about 30 seconds after the operation stopped and electric charge remains in the high voltage capacitor. When replacing or checking parts, short between oven chassis and the negative high terminal of the high voltage capacitor by using a properly insulated screwdriver to discharge.

4. When the 15A fuse is blown out due to the operation of the monitor switch; replace primary interlock switch, secondary interlock switch and interlock monitor switch.

5. After repair or replacement of parts, make sure that the screws are properly tightened, and all electrical connections are tightened.

6. Do not operate without cabinet.

CAUTION : Service personnel should remove their watches whenever working close to or replacing the magnetron.

WARNING :When servicing the appliance, need a care of touching or replacing high potential parts because of

electrical shock or exposing microwave. These parts are as follows - HV Transformer, Magnetron, HV Capacitor, HV Diode.

1. To remove cabinet

1) Remove three screws on cabinet back.

2) Push the cabinet backward.

2. To remove door assembly

1) Remove two screws which secure the stopper hinge top.

2) Remove the door assembly from top plate of cavity.

3) Reverse the above for reassembly.

NOTE : After replacing the door assembly, perform a check of correct alignment with the hinge and cavity front plate.

+ 26 hidden pages