Daewoo KOR-1A8Q0A, KOR-1A8Q1A Service Manual

S/M No. : R1A8Q1A002

Service Manual

Microwave Oven

Model: KOR-1A8Q0A

KOR-1A8Q1A

✔

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).

DAEWOO ELECTRONICS CORP.

http : //svc.dwe.co.kr Aug. 2004

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 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 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..............................................................................................................................................27

CIRCUIT CHECK PROCEDURE ........................................................................................................................27

P.C.B. CIRCUIT DIAGRAM.................................................................................................................................32

COMPONENT INFORMATION ...........................................................................................................................33

PRINTED CIRCUIT BOARD ...............................................................................................................................34

P.C.B. LOCATION NO ........................................................................................................................................35

EXPLODED VIEW AND PARTS LIST...............................................................................................................................36

DOOR ASSEMBLY .............................................................................................................................................36

CONTROL PANEL ASSEMBLY..........................................................................................................................36

TOTAL ASSEMBLY.............................................................................................................................................36

2

SAFETY AND PRECAUTIONS

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.

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. WAVEGUIDE FLANGES AND

GASKETS 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.

3

SPECIFICATIONS

MODEL

POWER SUPPLY

POWER

CONSUMPTION

MICROWAVE

GRILL

COMBINATION

MICROWAVE ENERGY OUTPUT

MICROWAVE FREQUENCY

OUTSIDE DIMENSIONS (W X H X D)

CAVITY DIMENSIONS (W X H X D)

NET WEIGHT

TIMER

FUNCTION SELECTIONS

POWER SELECTIONS

CAVITY VOLUME

KOR-1A8Q

120V~60Hz, SINGLE PHASE WITH GROUNDING

1400W

1000W

2450MHz

539x300x405 mm (21.2x11.8x16.0 in)

354x228x373 mm (13.9x9.0x14.7 in)

Approx. 15.5 kg (34.2 Ibs.)

59 min. 99 sec.

MICROWAVE

10 LEVELS

1.1 Cu. Ft.

* SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE.

4

EXTERNAL VIEW

1. OUTER DIMENSION

5

2. FEATURE DIAGRAM

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

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

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

4. SPATTRSHIELD

Protects the microwave outlet from splashes of cooking foods.

Automatically turns on during oven operating.

6. SAFETY INTERLOCK SYSTEM

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.

6

3. CONTROL PANEL

- KOR-1A8Q

STAGE

1

DEFROST

2 WEIGHT TI

AUTO

START

LOCK NO CUPS OZ Ib

POPCORN SOUP

BAKED

POTATO

PROZEN

PRESA

VEGETABLE MO RE LESS

BEVERAGE

Qui AUTO DEF.

1

4

7

POW ER

2

5

8

0

3

6

9

CLOCK

A START

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.

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.

7

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 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.

8

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 operatiion, 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 seal for obstructions and make sure the door is closed securely. The oven will not start cooking under the door is completely closed or the program has been reset.

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

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.

Touch POWER pad

Once

Twice

3 times

4 times

5 times

6 times

7 times

8 times

9 times

10 times

11 times

Power level(Display)

P-HI

P-90

P-80

P-70

P-60

P-50

P-40

P-30

P-20

P-10

P-00

Approximate Percentage of Power

100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

0%

9

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 safety 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 grounded.

It is imperative, therefore, to makes 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 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 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 a care when touching or replacing high potential parts because of electrical shock or exposing microvave. These parts are as follows - HV Transformer, Magnetron, HV

Capacitor, HV Diode.

10

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.

11

✔

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).

3. To remove door parts.

A03

A04

A01

A06

A05

A02

A07

A08

REF NO.

PART CODE

A01 3517005900

PART NAME

BARRIER-SCREEN *O

A03

A04

A05

3515202900

3511711300

3517005800

DESCRIPTION

PET T0.25

STOPPER HINGE *T AS KOR-121M0A

DOOR PAINTING AS KOR-1A1G0A

BARRIER-SCREEN *I PE T0.1

PP

POM

PW1

(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) Reverse the above steps for reassembly.

1

1

1

1

1

Q’TY REMARK

1

1

1

12

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.

(3) To reduce gap located on part ‘C’

• Loosen a screw on interlock switch assembly located top of oven body.

• Draw the interlock switch assembly inward as possible to engage with hook on the door bottom.

• Tighten a screw.

(4) To reduce gap located on part ‘D’

• Loosen a screw on interlock switch assembly located bottom of oven body.

and (4) are same as step (3).

NOTE : A small gap may be acceptable if the microwave leakage does not exceed 4mW/cm 2 .

13

✔

Caution



5. To remove control panel parts.

B03

B04

B02

B01

B05

B07

B06

REF NO.

PART CODE PART NAME DESCRIPTION

B02 3516722310 AF-345,HFA-700HT

B04

B05

B06

B07

7122401211

3513702800

441G430171

3516907910

SCREW TAPPING

LEVER DOOR OPEN

BUTTON SPRING

BUTTON DOOR OPEN

KOR-1A8Q0A

T2S TRS 4X12 MFZN

ABS XR-401 H-2938

SWP DIA 0.7

ABS AF-345,HFA-700HT

Q’TY REMARK

1

1

1

4

1

1

1

(1) Remove the screw which secure the control panel, push up two snap fits and draw forward the control panel assembly.

(2) Remove the door open lever from the control panel.

(3) Remove four screws which secure the PCB assembly to control panel.

(4) Disconnect membrane tail from the connector of the PCB assembly.

(5) Detach membrane from the control panel.

(6) Remove door open button and button spring from the control panel.

(7) Reverse the above steps for reassembly.

14

6. To remove high voltage 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. To remove magnetron.

1) Remove a screw which secure the magnetron.

2) Remove the magnetron.


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 2 for a fully assembled oven with door normally closed.

15

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.


9. To remove H.V.transformer.

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

2) Remove the H.V.transformer.


16

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 and presses the button of the secondary interlock switch to bring it under

“ON” condition.

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.

(3) Adjustment steps a) Loosen the two mounting screws.

b) Adjust interlock switch assembly position.

c) Make sure that lock lever moves smoothly after adjustment is completed.

d) Tighten completely two mounting screws.

NOTE :

Microwave emission test should be performed after adjusting interlock mechanism. If the microwave smission exceed

4mW/cm 2 , readjust interlock mechanism.

17

TROUBLE SHOOTING 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 transformer, disconnect one lead 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.

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

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

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

CONDITION

Fuse blows.

CHECK

Check continuity of interlock monitor switch with door closed

Replace fuse

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

Check continuity of primary winding of low voltage transformer

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

0

RESULT

Continuity

No Continuity

Continuity

Ω or infinite

Approx.

150~310

(normal)

Normal

Fuse again blows

CAUSE

Malfunction of interlock monitor switch

Shorted contacts of primary interlock switch.

Defective low voltage transformer

Defective high voltage capacitor

Defective high voltage transformer

REMEDY

Replace

NOTE 1

Replace

NOTE 1

Replace

Replace

Replace

18

CONDITION

Outlet has proper voltage Fuse does not blow.

CHECK

Check continuity of magnetron

Check continuity of power supply cord

Display do not shown countdown

RESULT

No

Continuity

No

Continuity

Normal

CAUSE

Defective magnetron

Open power supply cord

Defective touch control circuit

Malfunction of secondary interlock switch

REMEDY

Replace

Replace

Replace

Replace

NOTE

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.

CONDITION

Turn table motor and oven lamp do not turn on

CHECK

Check continuity of primary interlock switch

Check continuity of secondary interlock switch

Check D.C. voltage being supplied to RELAY (RY2) coil

RESULT

No

Continuity

No

Continuity

0 V

Approx.

15 VDC

CAUSE

Malfunction of primary interlock switch

Malfunction of secondary interlock switch


Faulty contacts of

RELAY (RY2) or open relay coil

REMEDY

Adjust or replace

Adjust or replace

Replace

Replace

19

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

CONDITION

No microwave oscillation

CHECK

Check continuity of high voltage capacitor terminals with wires removed

Check continuity of high voltage rectifier in forward and backward direction with DC megger

Connect megger leads to magnetron terminal and magnetron body

Check resistance of primary and secondary coil of high voltage transformer

Check continuity of magnetron with wires removed

RESULT

Continuity

Continuity in backward direction

Continuity

0

Ω or

No

∞

Continuity

Check continuity of filament terminal of high voltage transformer

No

Continuity

0 V

Check D.C. voltage being supplied to RELAY (RY1) coil

Approx

15 VDC

CAUSE


Defective high voltage rectifier

Defective magnetron


Defective magnetron



Faulty contacts of

RELAY (RY1) or open relay coil

REMEDY

Replace

Replace

Replace

Replace

Replace

Replace

Replace

Replace

20

(TROUBLE 4) The following visual conditions 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 are not on when they numbers is the display.

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

1

STAGE

2

DEFROST

AUTO

START

LOCK NO CUPS

OZ lb

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 programable and cooks normally but no display shows.

8. Display obviously jumps in time while counting down.

9. Display counts down noticeably too fast while cooking.

10. Display does not show the time of day when cancel 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.

CONDITION

Display does not show programming at all, even if keyboard is touched.

CHECK

Check each pad for continuity of the membrane keyboard for the following keyboard check procedure

RESULT

Normal

Abnormal

CAUSE

Malfunction of touch control circuit of control box sub-assembly

Malfunction of the membrane keyboard

REMEDY

Replace control box subassembly

Replace the membrane keyboard

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.

21

MEASUREMENT AND TEST

1. MEASUREMENT OF THE MICROWAVE POWER OUTPUT

Microwave output power can be checked by indirectly measuring 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 1000±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)

It 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 heat-up 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 :

P=4187 X ▲ T/t

• ▲ T is difference between initial and ending temperature.

• It is the heating time.

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

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)

• Heating time for power output:

A(second)

B(W)

70

600

64

650

60

700

56

750

52

800

49

850

47

900

44

950

42

1000

40

1050

38

1100

22

2. MICROWAVE RADIATION TEST

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.

PROCEDURES

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 600cc glass beaker with an inside diameter of approx.

95mm(3.5in.).

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/cm 2 .

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

23

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 10M

Ω once the capacitor is charged.

(3) A shorted capacitor will show continuous continuity.

(4) An open capacitor will show constant 10M

Ω

.

(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.

24

1) KOR-1A8Q0A

25

2) KOR-1A8Q1A

26

PRINTED CIRCUIT BOARD

1. CIRCUIT CHECK PROCEDURE

1. Low Voltage Transformer (DMR-602P) check

• The low voltage transformer is located on the P.C.B.

• Measuring condition: input voltage : 120V/Frequency : 60Hz

1 5

4

Terminal Voltage

4-7

LOAD

AC 12.6 V

NO LOAD

AC 14.7 V

2 3

NOTE :

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

NOTE :

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

2. Voltage check

• Key check point

NO

1

2

3

CHECK POINT

IC 1 PIN 7,41,42

IC 1 PIN 11

IC 1 PIN 23

REMARK

-5 VDC

GND

4.3V

0V

T:16.7ms(60Hz)

4 IC 1 PIN 8 OR 9

5V

0V

T:250ns(4MHz)

• Check method

NO

1

2

MEASURE POINT

MP1

MP2

WAVE FORM

DC -5V±0.25V

DC -12V±2.0V

REMEDY

Replace VL1, EC1

Replace EC2, D12, 13, 14

REMARK

NO LOAD

NO LOAD

NOTE :

Each measure point must be measured with GND points.

27

Bottom View

28

3. Display problems

NO CAUSE MEASUREMENT RESULT REMEDY

1 Defective Display Refer to “The display trouble shooting data”bellow.

Replace P.C.B. assembly i d

14 b c a g f e h G1 eo fo

G2

G3

G4

1

G5

Display layout

(Top View)

- The display trouble shooting data

TROUBLE

STAGE 1, LOCK DON”T COME ON.

STAGE 2, NO don’t come on.

WEIGHT DEFROST, CUPS don’t come on.

TIME DEFROST doesn’t come on.

AUTO START, g don’t come on.

SEGMENT “a” doesn’t come on from G1 to G5.

SEGMENT “b” doesn’t come on from G1 to G5.

SEGMENT “c” doesn’t come on from G1 to G5.

SEGMENT “d” doesn’t come on from G1 to G5.

SEGMENT “e” doesn’t come on from G1 to G5.

SEGMENT “f” doesn’t come on from G1 to G5.

SEGMENT “g” doesn’t come on from G1 to G5.

LOCK, NO, CUPS, g don’t come on.

STAGE 1, STAGE 2, TIME DEFROST, WEIGHT

DEFROST, AUTO START don’t come on.

DISPLAY NAME & PIN NO.

Digit 1 (G1), 10

Digit 2 (G2), 11

Digit 3 (G3), 14

Digit 4 (G4), 12

Digit 5 (G5), 13

SEGMENT a, 7

SEGMENT b, 6

SEGMENT c, 5

SEGMENT d, 4

SEGMENT e, 3

SEGMENT f, 2

SEGMENT g, 1

LOWER BAR h, 9

UPPER BAR i, 8

4. When there is no microwave oscillation.

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

Fan motor and turnatable motor do not rotate, but cook indicator in display comes on.

* Cause : RELAY 2 does not operate.

MICOM OUTPUT IN PIN NO.

13

15

21

18

17

16

14

33

29

20

19

31

32

30

D9

1N4002A

+12V DC

IC1

RY2

G5B-12V

A

40

FAN RY

TRAY RY

29

- Check method

STATE

RELAY 2 ON

RELAY 2 OFF

POINT

A

GND

+12VDC

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.

D8

1N4002A

Q11 KRC106M

A

IC1

39

MGT RY

B

- Check method

STATE

RELAY 1 ON

RELAY 1 OFF

POINT

A

+5VDC

GND

B

GND

+12VDC

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

A

CN1(D.O.M)

YW396-02V

2

1

C1

473

R17

1K

D6

1N4148M R15

1K

R16

10K

V1

B

C2

104

37

DOM

IC1

- Check method

STATE

1) DOOR OPEN

2) DOOR CLOSED

POINT

A

OPEN

CLOSE

CHECK NO

1

METHOD

Check the stage(ON,OFF) of the secondary interlock switch by resistance measurement.

30

B

5VDC

GND

REMEDY

Replace secondary interlock switch.

6. When the digital clock does not operate properly.

LVT1

D12

1N148M

R22

10K

R21

4.7K

ZD2

5.1V

C5

104

A

IC1

23

EXINT

POINT

A

WAVE FORM

4.3V

GND

T : 20ms(50Hz)

16.67ms(60Hz)

T

❈ If clock does not keep exact time, you must check resistor R15,16, zener diodeZD1.

31

2. PCB CIRCUIT DIAGRAM

32

3. COMPONENT INFORMATION

1) Transistor

Q9

Emitter Collector Base

2) Diode and Zener Diode

DIODE Cathode (K)

ZENER

DIODE

Cathode (K)

3) Digital Transistor

Q1-Q8

Q11-Q13

Emitter Collector Base

ANODE (A) D1-D6, D8-D14

ANODE (A) ZD1,ZD2

33

* Internal circuit

R1

BASE

R2

Emitter

RESISTOR

TYPE

KRC106M

R1

4.7K

KRA110M 4.7K

Collector

R2

47K

-

4. PRINTED CIRCUIT BOARD

34

✔

Caution



5. P.C.B. LOCATION NO.

NO.

1

2

3

4

7

PART NAME

RESISTOR

RESISTOR

RESISTOR

RESISTOR

5 RESISTOR

6 RESISTOR

RESISTOR

R11, R15, R17, R24

R13, R16, R22

R21

REF NO.

SPECIFICATION

1K, 1/6W, 5%

10K, 1/6W, 5%

4.7K, 1/6W, 5%

100K, 1/6W, 5% R10, R18, R19, R20

R14

R12

R23

100, 1/6W, 5%

51, 1/4W, 5%

R1, 2, 3, 4, 5, 6, 7, 8, 9 330, 1/4W, 5%

RA1 RGLD6X104J

8 RESISTOR

9 RARRAY

10

11

DIODE

DIODE

12 DIODE ZENER

13 DIODE ZENER

D1-D6, D10, D11, D12 1N4148M

D8, D9, D13, D14 1N4002A

ZD2

ZD1

LVT1

15 CAPACITOR ELECTRO EC1

5.1VB, 1/2W

3.9VB, 1/2W

DMR-602P

100MF 16V RSS

16

17

CAPACITOR ELECTRO

P. C. B. BARE

19 CARRAY

20 TRANSISTOR

21 TRANSISTOR

22 TRANSISTOR

EC2

M152

DP1

CA1

Q9

Q1-Q5

1000MF 25V RSS

M152

DDG611Q

KTA1270Y

KRA110M

KRC106M

YW396-02V

26 BUZZER

27 REGULATOR

30 RESONATOR

BZ1

VL1

28 CAPACITOR CERAMICQ C1

29 CAPACITOR CERAMIC C2, C3, C4, C5, C6

CR1

RY1

RY2

IC1

YM396-05AV

FCZ254-11

BM-20K

MC7805C

50V 473 AXIAL

50V 104 AXIAL

KBR-4.0MKSTF

G5J-1-TP-M12V

G5B-DC12V

HD404054A47S

PART CODE Q'TY

RD-AZ102J- 4

RD-AZ103J-

RD-AZ472J-

3

1

RD-AZ104J- 4

RD-AZ105J- 1

RD-AZ101J-

RD-4Z510J-

1

1

RD-4Z331J- 9

RA-87X104J- 1

DZN4148M--

DZN4002A--

9

4

DZTZ3R9B--

DZTZ3R9B--

5EPU035406 1

CEXF1C101V 1

1

1

CEXF1E102V 1

3514315400 1

DDDG611Q00 1

CN6XB-102M 1

TZTA1270Y- 1

TZRA110M-- 5

TZRC106M-- 6

3519150520 1

3519150510 1

441M367160 1

3515600100 1

1CPMC7805C 1

CCZF1H473Z 1

CCZF1H104Z 5

5PKBR40MKS 1

5SC0101108 1

5SC0101110 1

147S121MQ0 1

35

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

1) KOR-1A8Q0A

36

✔

Caution



1) KOR-1A8Q0A

REF NO

B00

F02

F04

F05

F06

F07

F08

F09

F11

F12

PART CODE

PKCPSWL900

3516004100

7122401211

7122401211

7112401011

35113TAN0H

7112401011

-

7121402511

3963821610

PART NAME

CONTROL PANEL AS

SPECIAL SCREW

SCREW TAPPING

SCREW TAPPING

SCREW TAPPING

CORD POWER AS

SCREW TAPPING

FUSE

SCREW TAPPING

MOTOR SHADED POLE

F14 3511800300 FAN

F15 3518002900 MAGNETRON

F16

F17

3516004000

7122400400

SPECIAL SCREW

SCREW TAPPING

F18

F19

F20

3513003200

3518302101

3518400400

HOLDER HV CAPACITOR

CAPACITOR HV

DIODE HV

F22 3516003700 SPECIAL SCREW

F23 3510312400 BASE

F24 7112401011 SCREW TAPPING

F25 3512100900 FOOT

F26

F27

7272400811

3515202800

SCREW TAPTITE

STOPPER HINGE *U AS

F29

F30

F31

4415A17352

4415A66600

3518571000

SW MICRO

SW MICRO

SWITCH PUSH

F34 3513811700 LOCK

F35 3513601500 LAMP

F36

F37

F38

7121400611

3966820200

3518905400

SCREW TAPPING

MOTOR SYNCRO

THERMOSTAT

F40

F41

7272400811

3511406200

SCREW TAPTITE

COVER WAVE GUIDE

F42 3517400620 COUPLER

F43 3514701501 ROLLER

F45 441CD35011 TRAY

T1 TRS LR4 POLE 4*10 MFZN

KOR-1A1G0A

T2S TRS 4*12 MFZN

T2S TRS 4*12 MFZN

T1 TRS 4*10 MFZN

3X16AWG 60X60 120-RTML

T1 TRS 4*10 MFZN

65TS 125V 20A

NYLON66

T2S PAN 4X25 MFZN

120V 60HZ MW10XA-M01

PP

PP+30%GLASS

SECC T0.6

DESCRIPTION

KOR-1A8Q0A

KOR-1A8Q0A

T2 BOLT FLANGE 5X12 DACRO

T2S TRS 4X8 MFZN

2100VAC 0.95UF #187

HVR-1X-3AB 12KV #187

DW-R11A0-1BT

TT3 HEX 4X8 FLG MFZN

T1TRS 4*10 MFZN

TT3 TRS 4X8 MFZN

SCP-1 T2.5

KOR-1A1G0A

VP-533A-OF SPNO #187 200G


MP 101C

VP-531A-OF/SZM-V16-FA-61

POM

POM

BL 125V 25W T25 C5A H187

T2S PAN 4X6 MFZN

120V 2W GM-16-12F17

OFF:90 ON:60 H #187 NB

TT3 TRS 4X8 MFZN

HEATPROOF PP

XAREC

TEFLON

PP

GLASS

1

1

1

1

5

2

4

1

1

1

1

1

1

1

1

1

1

1

1

2

1

1

1

1

1

2

3

1

Q'TY

1

1

1

1

1

1

3

1

1

1

1

1

1

1

1

1

1

1

1

37

2) KOR-1A8Q1A

38

✔

Caution



2) KOR-1A8Q1A

F35

F36

F37

F38

F39

F40

F41

F42

F43

F44

F27

F28

F29

F30

F31

F32

F33

F34

F14

F15

F16

F17

F18

F19

F20

F21

F22

F23

F24

F25

F26

F05

F06

F07

F08

F09

F10

F11

F12

F13

REF NO

A00

B00

F01

F02

F03

F04

PART CODE

3511711210

PKCPSWL900

3510805500

7112401011

3516110400

7122401211

7122401211

7272400811

35113X5W0L

7112401011

3518606600

7121402511

3963821600

3512517000

3511800300

PART NAME

DOOR AS

CONTROL-PANEL AS

CABINET AS

SCRW TAPPING

CAVITY AS

SCREW TAPPING

SCREW TAPPING

SCREW TAPTITE

CORD POWER AS

SCREW TAPPING

NOISE FILTER

SCREW TAPPING

MOTOR SHADED POLE

GUIDE WIND

FAN

3518002900

3516004000

7122400811

3513003200

3518303100

3518400400

3518113800

3516003700

3510312400

7112401011

3512100900

7272400811

3515202800

MAGNETRON

SPECIAL SCREW

SCREW TAPTITE

HOLDER HV CAPACITOR

CAPACITIR HV

DIODE HV

TRANS HV

SPECIAL SCREW

BASE

SCREW TAPPING

FOOT

SCREW TAPTITE

STOPPER HINGE *U AS

3512716810

4415A17352

4415A66910

3518571000

4415A66910

3513702600

3513811700

3513601500

HARNESS MAIN

SW MICRO

SW MICRO

SWITCH PUSH

SW MICRO

LEVER LOCK

LOCK

LAMP

7121400611

3966820200

3518905400

3513003410

7272400811

3511406200

SCREW TAPPING

MOTOR SYNCRO

THERMOSTAT

HOLDER THERMOSTAT

SCREW TAPTITE

COVER WAVE GUIDE

3517400620 COUPLER

3514701501 ROLLER

3512519300

441CD35011

GUIDE ROLLER

TRAY

DESCRIPTION

KOR-1A8Q0A

KOR-1A8Q0A

KOR-1A1G0A LOUVER

T1 TRS 4*10 MFZN

KOR-1A1G0A

T2S TRS 4*12 MFZN

T2S TRS 4*12 MFZN

TT3 TRS 4*8 MFZN

3*16AWG 80*80 120-RTML

T1 TRS 4*10 MFZN

DWLF-M17

T2S TRS 4*25 MFZN

120V 21W OEM-10DWX1-A07

PP

PP+30%GLASS

2M218J(F)P 6CF

T2 BOLT FLANGE 5*12 DACRO

T2S TRS 4*8 MFZN

SECC T0.6

2100VAC 0.98ßfi #187

HR-1X-3AB 12KV #187

DY-N95A0-16T

TT3 HEX 4*8 FLG MFZN

SBHG T0.7

T1 TRS 4*10 MFZN

PP DASF-130

TT3 TRS 4*8 MFZN

KOR-121M0A

KOR-1A1G1A



MP101C


POM

POM

BL 125V 25W T25 C5A H187

T2S PAN 4*16 MFZN

120V 2W GM-16-12F17

OFF:90 ON:60 H #187 NB

PP(BK)

TT3 TRS 4*8 MFZN

HEATPROOF PP

XAREC

TEFRON

PP 5113MF6 A353R

GLASS

39

1

1

1

3

1

1

2

1

1

1

1

1

1

1

1

1

1

1

1

4

1

1

1

1

1

1

2

1

1

1

5

1

1

1

1

2

1

1

1

1

Q'TY

1

1

1

1

1

3

S/M NO. : R1A8Q1A002

DAEWOO ELECTRONICS CORP.

686, AHYEON-DONG MAPO-GU SEOUL, KOREA

C.P.O. BOX 8003 SEOUL, KOREA

TELEX: DWELEC K28177-8

CABLE: “DAEWOOELEC”

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