Daewoo KOR-1A7Q0A, KOR-1A7Q Service Manual

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Page 1

Service Manual

Microwave Oven

Model: KOR-1A7Q0A

DAEWOO ELECTRONICS CO., LTD.

S/M No. : R1A7Q0A001

http : //svc.dwe.co .kr Nov. 2002

✔

Caution

: In this Manual, some parts can be changed for improving, their performance without notice in the parts list. So, if you need the latest parts information,please refer to PPL(Parts Price List) in Service Information Center (http://svc.dwe.co.kr).

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PRECA UTIONS T O BE OBSERVED BEFORE AND DURING SER VICING T O AVOID POSSIBLE EXPOSURE T O EXCESSIVE MICROW AVE 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 if 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 power to the microwave oven 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.

TABLE OF CONTENTS

SAFETY AND PRECAUTIONS........................................................................................................................................3

FOR SAFE OPERATION...........................................................................................................................................3

FOR SAFE SERVICE PROCEDURES .....................................................................................................................3

SPECIFICATIONS ............................................................................................................................................................4

EXTERNAL VIEW.............................................................................................................................................................5

OUTER DIMENSION.................................................................................................................................................5

FEATURE DIAGRAM.................................................................................................................................................6

CONTROL PANEL.....................................................................................................................................................7

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

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

DISASSEMBLY AND ASSMBLY...................................................................................................................................10

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

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

MESUREMENT 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...........................................................................................................................31

DOOR ASSEMBLY..................................................................................................................................................31

CONTROL PANEL ASSEMBLY..............................................................................................................................31

TOTAL ASSEMBLY.................................................................................................................................................31

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SAFETY AND PRECA UTIONS

CAUTION : 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.

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, (c) attempt to ascertain the cause of the excessive leakage, (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

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. WAVEGUIDES FLANGES AND GASKETS MUST BE SECURED. NEVER OPERATE THE DEVICE WITHOUT A MICROWAVE ENERGY ABSORBING LOAD ATTACHED. NEVER LOOK INTO AN OPEN WAVEGUIDE OR ANTENNA WHILE THE DEVICE IS ENERGIZED.

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SPECIFICATIONS

MODEL KOR-1A7Q0A POWER SUPPLY 120V~60HZ, SINGLE PHASE WITH EARTHING

MICROWAVE 1400 W

POWER

GRILL

CONSUMPTION

COMBINATION MICROWAVE ENERGY OUTPUT 1000W MICROWAVE FREQUENCY 2450MHz OUTSIDE DIMENSIONS (W X H X D) 539 x 300 x 431 mm (21.2 x 11.8 x16.9 in.) CAVITY DIMENSIONS (W X H X D) 534 x 228 x 373 mm (13.9 x 9.0 x16.9 in.) NET WEIGHT APPROX. 16.7kg TIMER 99min. 99sec. FUNCTION SELECTIONS MICROWAVE POWER SELECTIONS 10 LEVELS CAVITY VOLUME 1.3 Cu. Ft

* Specifications are subject to change without notice.

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EXTERNAL VIEW

539 431

300

1. OUTER DIMENSION

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9 4

1. DOOR SEAL

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

2. DOOR HOOK

When 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. SPATTER SHIELD

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 resisant glass. The tray must always be in proper position before operating. Do not cook food directly on the tray.

9. OVEN FRONT PLATE

10. ROLLER GUIDE

Supports the glass cooking tray.

2. FEATURE DIAGRAM

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BeveragePopcorn

Dinner

Plate

Frozen

Pizza

Baked Potato

Fresh

Vegetable

Clock

A.Start

Power

Muffin Soup

More Less

Quick Cook Auto Defrost

123 456 789

Stop/Clear Start

WEIGHT

DEFROST

STAGE

TIME

LOCK NO CUPS lboz

AUTO

START

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. Quick 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. Clock A.Start - Used to set clock and also used to set a delayed auto start.

10. Stop/Clear - Used to stop the oven operation or to delete the cooking data.

11. Start - Used to start the oven.

3. CONTROL PANEL

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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.A way 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. Position the oven as far from them as possible.

4.A way 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 suppl y

• Check your local power source. This microwave oven requires a current of approximately 15 amperes, 120Volts, 60Hz grounded outlet.

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

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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. 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.

5. Each time a pad is touched, a BEEP will sound to acknowledge the touch.

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

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

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

9. When the STOP/CLEAR pad is touched during the oven operation, the oven stops cooking and all information retained. To erase all information (except the present time), touch the STOP/CLEAR pad once more. If the oven door is opened during the oven operation, all information is retained.

10. 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 until the door is completely closed or the program has been reset.

Wattage output chart

The power level is set by touching 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 outlet.

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%

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DISASSEMBLY AND ASSEMBLY

- 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 wear 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 grounded. It is imperative, therefore, to make sure it is grounded properly before beginning repair work.

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

For about 30 seconds after the operation has stopped, 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 20A fuse is blown 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, take care when touching or replacing high potential parts because of

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

SHORT

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1. To remo ve cabinet

1) Remove three screws on cabinet back.

2) Push the cabinet backward.

2. To remo ve door assembl y

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.

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3. To remove door parts.

REF NO. PART CODE PART NAME DESCRIPTION Q’TY REMARK

A01 3511711300 DOOR PAINTING AS KOR-1A1G0A 1 A02 3513100750 HOOK POM 1 A03 3515102000 SPRING HOOK PW1 1 A04 3517005930 BARRIER-SCREEN * O GLASS T3.2 1 A05 3512204370 FRAME DOOR ABS XR-401 SR-0320G 1 A06 3511604720 DECORATOR DOOR * T STS430 H/L 0.5T 1 A07 3511604730 DECORATOR DOOR * U STS430 H/L 0.5T 1 A08 3515202900 STOPPER HINGE * T AS KOR-121M0A 1 A09 3512602600 HANDLE DOOR * T STS304 T0.6 HAIR LINE 1 A10 3512602700 HANDLE DOOR * U ABS XR-401 H-2938 1 A11 7122401211 SCREW TAPPING T2S TRS 4*12 MFZN 2 A12 3517005800 BARRIER-SCREEN * I PETP T0.1 1 A13 3512301900 GASKET DOOR PP 1 A14 3511609510 DECORATOR DOOR * L DECORATOR DOOR * R 1 A15 3511609310 STS430 H/L T0.5 STS430 H/L T0.5 1

(1) Remove the gasket door from door plate. (2) Remove the barrier screen inner from door plate. (3) Remove the door frame from door plate. (4) Remove the stopper hinge top from door plate. (5) Remove the spring and the hook. (6) Remove the barrier screen outer from door frame. (7) Remove two screws holding the handle. (8) Remove the handle from door frame. (9) Reverse the above steps for reassembly.

✔ Caution:

In this Service Manual, some parts can be changed for improving, their performance without notice in the parts list. So, if you need the latest parts information, please refer to PPL(Parts Price List) in Service information Center(http://svc.dwe.co.kr)

Page 13

4. Method to reduce the gap between the door seal and the oven front surface.

(1) To reduce gap located on part ‘A’.

• Loosen two screws on stopper hinge top, and then push the

door to contact the door seal to oven front surface.

• Tighten two screws.

(2) To reduce gap located on part ‘B’.

• Loosen two screws on stopper hinge under, and then push the door to contact the door seal to oven front surface.

• Tighten two screws.

NOTE : A small gap may be acceptable if the microwave leakage does not exceed 4mW/cm2.

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5. To remove control panel parts.

REF NO. PART CODE PART NAME DESCRIPTION Q’TY REMARK

B01 3511604820 DECORATOR C-PANEL STS430 H/L 0.5T 1 B02 3518523700 SWITCH MEMBRANE KOR-1A7Q0A 1 B03 3516722380 CONTROL-PANEL ABS AF-348 VT-0826 1 B04 PKMPMSWA00 PCB AS KOR-818Q7, 8A(M2) 1 B05 7122401211 SCREW TAPPING T2S TRS 4*12 MFZN 4

(1) Remove the screw which secure the control panel, push up two snap fits and draw forward the control panel assembly. (2) Remove four screws which secure the PCB assembly to control panel. (3) Disconnect membrane tail from the connector of the PCB assembly. (4) Detach membrane from the control panel. (5) Reverse the above steps for reassembly.

✔ Caution:

B01 B02 B03 B04 B05

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NOTE : Never install the magnetron without the metallic gasket plate which is packed with each magnetron to

prevent microwave leakage. Whenever repair work is carried out on magnetron, check the microwave leakage. It shall not exceed 4mW/cm

for a fully assembled oven with door normally closed.

6. T o remo ve high v oltage capacitor.

1) Remove a screw which secure the grounding ring terminal of the H.V. diode and the capacitor holder.

2) Remove the H.V. diode from the capacitor holder.

3) Reverse the above steps for reassembly.

◆ High voltage circuit wiring

7. T o remo ve magnetr on.

1) Remove a screw which secure the magnetron.

2) Remove the magnetron.

3) Reverse the above steps for reassembly.

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8. To remove wind guide assembly.

1) Remove a screw which secure the wind guide assembly.

2) Draw forward the wind guide assembly.

3) Pull the fan from the motor shaft.

4) Remove two screws which secure the motor shaded pole.

5) Remove the motor shaded pole.

6) Reverse the above steps for reasembly.

9. To remove H.V.transformer .

1) Remove four screws holding the H.V.transformer.

2) Remove the H.V.transformer.

3) Reverse the above steps for reassembly.

NOISE FILTER

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INTERLOCK MECHANISM AND ADJUSTMENT

The door lock mechanism is a device which has been specially designed to completely eliminate microwave radiation when the door is opened during operation, and thus to perfectly prevent the danger resulting from the leakage of microwave.

(1) Primary interlock switch

When the door is closed, the hook locks the oven door. If the door is not closed properly, the oven will not operate. When the door is closed, the hook pushes the button of the microswitch. Then the button of the primary interlock switch bring it under ON condition.

(2) Secondary interlock switch and interlock monitor switch

When the door is closed, the hook pushes the lock lever downward. The lock lever presses the button of the interlock monitor switch to bring it under NO condition. The lock lever presses the button of the secondary interlock switch to bring it under ON condition.

(3) Adjustment steps

a) Loosen the one mounting screw. b) Adjust interlock switch assembly position. c) Make sure that lock lever moves smoothly after adjustment is completed. d) Tighten completely two mounting screws.

Condition: Door Close Condition: Door Open

Mounting Screw

Front Plate

Under Hook

Upper Hook

Interlock Maniter Switch

Secondary Interlock Switch

Laver Lock

Primary Interlock Switch

ADJUSTMENT :

Interlock monitor switch When the door is closed, the interlock monitor switch should be changed (NO condition) before other switches are closed.

When the door is opened, the interlock monitor switch should be changed (NC condition) after other switches are opened.

NOTE :

Microwave emission test should be performed after adjusting interlock mechanism. If the microwave emission exceed 4mW/cm

, readjust interlock mechanism.

Page 18

TROUBLE SHOO TING GUIDE

Following the procedure below to check if the oven is defective or not.

1) Check grounding before trouble checking.

2) Be careful of the high voltage circuit.

3) Discharge the high voltage capacitor.

4) When checking the continuity of the switches, fuse or high voltage tranformer, disconnect one load wire from these parts and check continuity with the AC plug removed. To do otherwise may result in a false reading or damage to your meter.

(TROUBLE 1) Oven does not operate at all : any inputs can not be accepted.

NOTE :

When electric parts are checked, be sure the power cord is not inserted the wall outlet.

Check wire harness, wiring and connection of the terminals and power cord before check the parts listed below.

CONDITION CHECK

Check continuity of interlock monitor switch with door closed

Check continuity of of primary interlock switch contact with door partially open until interlock monitor switch contact close

Malfunction of interlock monitor switch

Shorted contacts of primary interlock switch.

RESULT

Continuity

No Continuity

Replace fuse

CAUSE REMEDY

Replace NOTE 1

Fuse blows.

Replace NOTE 1

Defective low voltage transformer

0Ω or infinite

Approx.

150~310

(normal)

Replace

Check continuity of primary winding of low voltage transformer

Defective high voltage capacitor

Normal

Replace

Disconnect one side of the lead wire connected form high voltage transformer to the high voltage capacitor and operate the unit

Continuity

Defective high voltage transformer

Fuse again

blows

Replace

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CONDITION CHECK

Check continuity of magnetron

Defective

magnetron

RESULT

Continuity

CAUSE REMEDY

Replace

Outlet has

proper

voltage Fuse

does not

blow.

CONDITION CHECK

Check continuity of primary

interlock switch

Malfunction of

primary interlock

switch

RESULT

Continuity

CAUSE REMEDY

Adjust or

replace

Turn table motor and oven lamp

do not turn

Check continuity of secondary

interlock switch

Malfunction of

secondary

interlock

switch

Continuity

Adjust or

replace

Check D.C. voltage being

supplied to RELAY (RY2) coil

Defective touch

control circuit

0 V Replace

Faulty contacts of

RELAY (RY2) or

open relay coil

Approx.

15 VDC

Replace

Display do not shown

countdown

Malfunction of

secondary

interlock switch

Replace

Check continuity of

power supply cord

Open power

supply cord

Continuity

Replace

Defective touch

control circuit

Normal

Replace

NOTE 1

All these switches must be replaced at the same time, please refer to “Interlock Mechanism And Adjustment”.

(TROUBLE 2) Display shows all figures selected, but oven does not start cooking, even though desired program and

time are set and start pad is tapped.

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CONDITION CHECK RESULT

Check continuity of high

voltage capacitor terminals

with wires removed

Continuity

CAUSE

Defective high

voltage

transformer

REMEDY

Replace

microwave

oscillation

Check continuity of high voltage

rectifier in forward and backward

direction with DC megger

Continuity in

backward

direction

Defective high

voltage rectifier

Replace

Connect megger leads to

magnetron terminal and

magnetron body

Continuity

Defective

magnetron

Replace

Check resistance of primary and

secondary coil of high voltage

transformer

0 Ω or ∞

Defective high

voltage

transformer

Replace

Check continuity of magnetron

with wires removed

Continuity

Defective

magnetron

Replace

Check continuity of filament

terminal of high voltage

transformer

Continuity

Defective high

voltage

transformer

Replace

Check D.C. voltage being

supplied to RELAY (RY1) coil

0 V

Defective touch

control circuit

Replace

Approx

15 VDC

Faulty

contacts or

RELAY (RY1)

or open

relay coil

Replace

(TROUBLE 3) No microwave oscillation even though fan motor rotates.

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(TROUBLE 4) The following visual conditions inditions indicate a probable defective touch control circuit or

membrane switch assembly

1. Incomplete segments,

1) Segments missing.

2) Partical segments missing.

3) Digit flickering other than normal display slight flickering.

4) " :0" does not display when power is on.

2. A distinct change in the display is not on when they should be.

3. One or more digits in the display are not on when they should be.

4. Display indicates a number different from one touched.

5. Specific numbers (for example 2 or 3) will not display when the panel is touched.

6. Display does not count down or up with time cooking or clock operation.

7. Oven is programmable and cooks normally but no display shows.

8. Display obviously jumps in time while counting down.

9. Display counts down noticeable too fast while cooking.

10. Display does not show the time of day when clear pad is touched.

11. Oven lamp and turntable motor do not stop although cooking is finished. Check if the RELAY 2 contacts close if they are close, replace touch control circuit.

NOTE

Before following the particular steps listed above in the trouble shooting guide for the membrane keyboard's, failure, please check for the continuity of each wire-harness between the membrane keyboard and P.C.B. assembly.

CONDITION CHECK

Check rach pad for

continuity of the membrane

keyboard for the following

keyboard check procedure

Malfunction

of touch control circuit of control box

sub-assembly

RESULT

Normal

CAUSE REMEDY

Replace

control box

sub-assembly

Malfunction

of the membrane

keyboard

Abnormal

Replace the

membrane

keyboard

Display does

not show

programming

at all, even if

keyboard is

touched.

M/W DEF LOCK lbTIMER

Page 22

MEASUREMENT AND TEST

1. MEASUREMENT OF THE MICROW AVE POWER OUTPUT

Microwave output power can be checked by indirectly mmeasuring the temperature rise of a certain amount of water exposed to the microwave as directed below.

PROCEDURE

1. Microwave power output measurement is made with the microwave oven supplied at rated voltage and operated at its maximum microwave power setting with a load of 100 ± 5cc of potable water.

2. The water is contained in a cylindrical borosilicate glass vessel having a maximum material thickness of 3 mm and an outside diameter of approximately 190 mm.

3. The oven and the empty vessel are at ambient temperature prior to the start of the test. The initial temperature of the water is 10 ± 2°C (50 ± 3.6°F). If is measured immediately before the water is added to the vessel. After addition of the water to the vessel, the load is immediately placed on the center of the shelf, which is in the lowest normal position.

4. Microwave power is switched on.

5. Heating time should be exactly A seconds. (Refer to table as following) Heating time is measured while the microwave generator is operating at full power. The filament heatup time for magnetron is not included.

6. The initial and final temperature of water is selected so that the maximum difference between the ambient and final water temperature is 5K.

7. The microwave power output P in watts is calculated from the following formula:

• ∆ T is difference between initial and final temperature.

• t is the heating time.

The power measured be B (Refer to SPECIFICATIONS) W ± 10.0 %.

✻ Heating time for power output:

CAUTION

1. Water load should be measured exactly to 1 liter.

2. Input power voltage should be exactly specified voltage (Refer to SPECIFICATIONS).

3. Ambient temperature should be 20 ± 2°C (68 ± 3.6°F)

P = 4187 X ∆ T/t

600

650

700

750

800

850

900

950421000401050381100

A (second)

B (W)

Page 23

2. MICROW AVE RADIATION TEST

PROCEDURE

1. Prepare Microwave Energy Survey Meter, 600cc glass beaker, and glass thermometer 100°C (212°F).

2. Pour 275cc ± 15cc of tap water initially at 20 ± 5°C (68 ± 9°F) in the 600 cc glass beaker with an inside diameter of approx. 95 mm(3.5 in.).

3. Place it at the center of the tray and set it in a cavity.

4. Close the door and operate the oven.

5. Measure the leakage by using Microwave Energy Survey Meter with dual ranges, set to 2450MHz.

1) Measured radiation leakage must not exceed the value

prescribed below. Leakage for a fully assembled oven with door normally closed must be less than 4mW/cm2.

2) When measuring the leakage, always use the 5 cm (2 in.)

space cone with probe. Hold the probe perpendicular to the cabinet and door. Place the space cone of the probe on the door, cabinet, door seem, door viewing screen, the exhaust air vents and the suction air vents.

3) Measuring should be in a counter-clockwise direction at a rate of 1 in./sec. If the leakage of the cabinet door

seem is unknown, move the probe more slowly.

4) When measuring near a corner of the door, keep the probe perpendicular to the areas making sure the probe

end at the base of the cone does not get closer than 2 in. from any metal. If it does not, erroneous reading may result.

CAUTION

1. Make sure to check the microwave leakage before and after repair of adjustment.

2. Always start measuring of an unknown field to assure safety for operating personnel from microwave energy.

3. Do not place your hands into any suspected microwave radiation field unless the safe density level is known.

4. Care should be taken not to place the eyes in direct line with the source of microwave energy.

5. Slowly approach the unit under test until the radiometer reads an appreciable microwave leakage from the

unit under the test.

Page 24

3. COMPONENT TEST PROCEDURE

• High voltage is present at the high voltage terminal of the high voltage transformer during any cooking cycle.

• It is neither necessary nor advisable to attempt measurement of the high voltage.

• Before touching any oven components or wiring, always unplug the oven from its power source and discharge the

capacitor.

1. High voltage transformer

1) Remove connections from the transformer terminals and check continuity.

2) Normal readings should be as follows :

Secondary winding ... Approx. 110 Ω ±10% Filament winding ... Approx. 0 Ω Primary winding ... Approx. 1 Ω

2. High voltage capacitor

1) Check continuity of capacitor with meter on the highest OHM scale.

2) A normal capacitor will show continuity for a short time, and then indicate 10MΩ once the capacitor charged.

3) A shorted capacitor will show continuous continuity.

4) An open capacitor will show constant 10MΩ.

5) Resistance between each terminal and chassis should be infinite.

3. High voltage diode

1) Isolate the diode from the circuit by disconnecting the leads.

2) With the ohmmeter set on the highest resistance scale measure the resistance across the diode terminals.

Reverse the meter leads and again observe the resistance reading. Meter with 6V, 9V or higher voltage batteries should be used to check the front-back resistance of the diode, otherwise an infinite resistance may be read in both directions. A normal diode's resistance will be infinite in one direction and several hundred k Ω in the other direction.

4. Magnetron

For complete magnetron diagnosis, refer to "Measurement of the Microwave Power Output." Continuity checks can only indicate and open filament or a shorted magnetron. To diagnose for an open filament or a shorted magnetron,

1) Isolate magnetron from the circuit by disconnecting the leads.

2) A continuity check across magnetron filament terminals should indicate 0.1 Ω or less.

3) A continuity check between each filament terminal and magnetron case should read open.

5. Fuse

If the fuse in the primary and monitor switch circuit is blown when the door is opened, check the primary and monitor switch before replacing the blown fuse. In case the fuse is blown by an improper switch operation, replace the defective switch and fuse at the same time. Replace just the fuse if the switches operate normally.

Page 25

WIRING DIA GRAM

Page 26

PRINTED CIRCUIT BO ARD

1. CIRCUIT CHECK PROCEDURE

1. Low voltage transformer check

The low voltage transformer is located on the P.C.B. Measuring condition: Input voltage: 120V / Frequency: 60Hz

2. Voltage Check

- Key check point

- Check method

NOTE

1. Refer to Ciruit Diagram (point 4).

2. Secondary side voltage of the low voltage transformer changes in proportion to fluctuation of power source voltage.

3. The allowable tolerance of the secondary voltage is within ± 5% of nominal voltage.

NOTE

Each measure point must be measured with GND points.

Terminal Voltage

3-5

LOAD

AC 12.6 V

NO LOAD AC 14.7 V

NO CHECK POINT REMARK

1 IC1 PIN 7, 41, 42 +5VDC 2 IC1 PIN 23

3 IC1 PIN 8 OR 9

T : 16.67ms(60Hz)

T : 250 ns(4MHz)

NO MEASURE POINT WAVE FORM REMEDY REMARK

1 MP1 DC -5V±0.25V Replace VL1, EC1 NO LOAD 2 MP2 DC -12V±2.0V Replace EC2, D11, 13, 14 NO LOAD

Page 27

MP1

MP2

Mesure point

Page 28

3. When there is no microwave oscillation

1) When touching START pad, oven lamp does not turn on.

Fan motor do not rotate, but cook indicator in display comes on. ✻ Cause : RELAY 2 does not operate. → refer to Circuit Diagram (point 3)

- Check method

2) When touching START pad, oven lamp turns on.

Fan motor and turntable rotate and cook indicator in display comes on. ✻ Cause : RELAY 1 does not operate. → refer to Circuit Diagram (point 2)

- Check method

4. When the door is opened during operation the count down timer does not stop.

→ refer to Circuit Diagram (point 1)

- Check method

5. When the digital clock does not operate properly.

→ refer to Circuit Diagram (point 5)

❈ If clock does not keep exact time, you must check resistor R21, 22 zener diode ZD2.

POINT

STATE

RELAY 2 ON +5VDC GND

RELAY 2 OFF GND +12VDC

POINT

STATE

RELAY 1 ON +5VDC GND

RELAY 1 OFF GND +12VDC

POINT

STATE

1) DOOR OPEN OPEN +5VDC

2) DOOR CLOSED CLOSE GND

CHECK NO HETHOD REMEDY

1 Check the stage(ON, OFF) of the secondary interlock Replace door open monitor switch.

switch by resistance measurement.

POINT WAVE FORM

T: 16.67 ms(60Hz)

Page 29

2. P.C.B. CIRCUIT DIAGRAM

Page 30

NO NAME SYMBOL SPECIFICATION PART CODE Q’TY

1 BUZZER BZ1 BM-20K 3515600100 1 2 C ARRAY CA1 7P(6) 1000PF M 50V CN6XB-102M 1 3 CAPACITOR CERA C1 50V F 0.047MF Z CCZF1H473Z 1 4 CAPACITOR CERA C2~6 50V HIKF 0.1MF Z CCZF1H104Z 5 5 CAPACITOR ELEC EC1 16V RSS 100MF CEXF1C101V 1 6 CAPACITOR ELEC EC2 25V RSS 1000MF CEXF1E102V 1 7 CONNECTOR WAFER CN1 YW396-02V 3519150520 1 8 CONNECTOR FILM CN2 FCZ 254-11 441M367160 1

9 CONNECTOR WAFER CN3 YW396-05AV 3519150510 1 10 DIODE RECTIFY D4~6 1N4148M DZN4148M-- 3 11 DIODE RECTIFY "D1~3,8,9,11,12" 1N4148 DZN4148--- 7 12 DIODE RECTIFY "D13,14" 1N4004A DZN4004A-- 2 13 DIODE ZENER ZD1 UZ- 3.3BSB 1/2W DZUZ3R3BSB 1 14 DIODE ZENER ZD2 UZ- 5.1BSB 1/2W DZUZ5R1BSB 1 15 IC MICOM IC1 HD404054A47S 147S121MQ0 1 16 IC REGULATOR VL1 MC7805C 1CPMC7805C 1 17 LED DISPLAY DP1 DDG-611Q DDDG611Q00 1 18 PCB MAIN M152 81.5X139.9 3514315400 1 19 R ARRAY RA1 7P(6) 1/8 100K J RA-87X104J 1 20 RESISTER R12 1/6W 100 5% RD-AZ201J- 1 21 RESISTER "R11,15,17,24" 1/6W 1K 5% RD-AZ102J- 4 22 RESISTER R21 1/6W 4.7K 5% RD-AZ472J- 1 23 RESISTER "R13,16,22" 1/6W 10K 5% RD-AZ103J- 3 24 RESISTER "R10,18~20" 1/6W 100K 5% RD-AZ104J- 4 25 RESISTER R14 1/6W 1M 5% RD-AZ105J- 1 26 RESISTER R1~9 1/4W 330 5% RD-4Z331J- 9 27 RESISTER R23 1/4W 51 5% RD-4Z510J- 1 28 RESONATOR CERA CR1 CRT 4.00MS 5P4R00MTS- 1 29 SW RELAY RY2 G5J-1-TP-M12V 5SC0101108 1 30 SW RELAY RY3 CS11-12SH 1C 1P 5SC0101128 1 31 TRANSISTOR Q1~5 KRA-110M TZRA110M-- 5 32 TRANSISTOR "Q6~8,11~13" KRC-106M TZRC106M-- 6 33 TRANSISTOR Q9 KTA-1266Y TZTA1266Y- 1 34 TRANS POWER LVT DMR-602P 5EPU035406 1 35 WIRE COPPER "J1~5,9" 1/0.52 TIN COATING 85801052GY 6 36 WIRE COPPER "J6~8,10" 1/0.52 TIN COATING 85801052GY 4 37 WIRE COPPER "SJ2,SJ3" 1/0.52 TIN COATING 85801052GY 2

3. P.C.B. LOCATION NO.

✔ Caution:

Page 31

EXPLODED VIEW AND PARTS LIST

1. DOOR ASSEMBLY

Refer to Disassembly and assembly

2. CONTROL PANEL ASSEMBLY

Refer to Disassembly and assembly

3. TOTAL ASSEMBLY

Page 32

REF NO PART CODE PART NAME DESCRIPTION Q'TY

A00 3511711260 DOOR AS KOR-1A7Q0A 1 B00 3516727420 CONTROL PANEL AS KOR-1A7Q0A 1

F01 3510802510 CABINET STS430 T0.5 HL 1 F02 3516004100 SPECIAL SCREW T1 TRS LR4 POLE 4X10 MFZN 3 F03 3516110400 CAVITY AS KOR-1A1G0A 1 F04 7122401211 SCREW TAPPING T2S TRS 4*12 MFZN 1 F05 7122401211 SCREW TAPPING T2S TRS 4*12 MFZN 1 F06 7122401011 SCREW TAPPING T2S TRS 4*10 MFZN 1 F07 35113TCN35 CORD POWER AS 3X16 AWG 40X40 120-RTML 1 F08 7122401011 SCREW TAPPING T2S TRS 4*10 MFZN 1 F09 FUSE 65TS 125V 20A 1 F10 HOLDER FUSE NYLON66 1 F11 7121402511 SCREW TAPPING T2S PAN 4X25 MFZN 2 F12 3963821610 MOTOR SHADED POLE 120V 60HZ MW10XA-M01 1 F13 3512517000 GUIDE WIND PP 1 F14 3511800300 FAN PP+30% GLASS 1 F15 3518002900 MAGNETRON 2M218J(F)P 1 F16 3516004000 SPECIAL SCREW T2 BOLT FLANGE 5X12 DARCO 1 F17 7272400811 SCREW TAPTITE TT3 TRS 4X8 MFZN 1 F18 3513003200 HOLDER HV CAPACITOR SECC T0.6 1 F19 3518303100 CAPACITOR HV 2100VAC 0.98UF #187 +3 -0 1 F20 3518400400 DIODE HV HVR-1X-3AB 12KV #187 1 F21 3518113801 TRANS HV DY-N95A0-16T 1 F22 3516003700 SPECIAL SCREW T2 FLANGE 5X8 MFZN 4 F23 3510312400 BASE SBHG T0.7 1 F24 7112401011 SCREW TAPPING T1 TRS 4X10 MFZN 5 F25 3512100900 FOOT PP DASF-310 2 F26 7272400811 SCREW TAPTITE TT3 TRS 4X8 MFZN 1 F27 3515202800 STOPPER HINGE *U AS KOR-121M0A 1 F28 3512716800 HARNESS MAIN KOR-1A1G0A 1 F29 4415A66910 SW MICRO "VP-531A-OF/SZ,-V16-FA-61" 1 F30 4415A17352 SW MICRO VP-533A-OF SPNO #187 200G 1 F31 4415A66910 SW MICRO "VP-531A-OF/SZ,-V16-FA-61" 1 F32 3513702620 LEVER LOCK POM 1 F33 3513811750 LOCK PP 1 F34 3518571000 SWITCH PUSH MP101C 1 F35 3513601500 LAMP BL 120V 25W T25 C5A H187 1 F36 7121400611 SCREW TAPPING T2S PAN 4X6 MFZN 1 F37 3966820200 MOTOR SYNCRO 120V 2W GM-16-12F17 1 F38 3518905400 THERMOSTAT OFF:90 ON:60 H #187 NB 1 F39 3513003410 HOLDER THERMOSTAT PP(BK) 1 F40 7272400811 SCREW TAPTITE TT3 TRS 4X8 MFZN 2 F41 3511406200 COVER WAVE GUIDE HEATPROOF PP 1 F42 3517400620 COUPLER XAREC 1 F43 3514701501 ROLLER TEFLON D:14.5 3 F44 3512519300 GUIDE ROLLER PP 5113MF6 A353B 1 F45 441CD35011 TRAY GLASS DIA:325 1320G 1

✔ Caution:

Page 33

S/M NO. : R1A7Q0A001

DAEW OO ELECTRONICS CO ., LTD.

686, AHYEON-DONG MAPO-GU SEOUL, KOREA C.P.O. BOX 8003 SEOUL, KOREA TELEX: DWELEC K28177-8 CABLE: “DAEWOOELEC”

PRINTED DATE: Nov, 2002

Daewoo KOR-1A7Q0A, KOR-1A7Q Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual