DAEWOO ELECTRONICS KOG-3767 User manual

Service Manual
http : //svc.dwe.co.kr Sep. 1999
DAEWOO ELECTRONICS CO., LTD.
Microwave Oven
Model: KOG-3767
S/M No. : G37671S001

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SAFETY AND PRECAUTIONS ........................................................................................................ 2
SPECIFICATIONS ............................................................................................................................ 3
EXTERNAL VIEW ............................................................................................................................ 4
1. OUTER DIMENSION .................................................................................................................... 4
2. FEATURE DIAGRAM ................................................................................................................... 5
INSTALLATION ................................................................................................................................ 6
OPERATIONS AND FUNCTIONS ................................................................................................... 7
DISASSEMBLY AND ASSEMBLY .................................................................................................. 8
INTERLOCK MECHANISM AND ADJUSTMENT ...........................................................................17
TROUBLE SHOOTING GUIDE ........................................................................................................ 18
MEASUREMENT AND TEST ...........................................................................................................20
1. MEASUREMENT OF THE MICROWAVE POWER OUTPUT ..................................................... 20
2. MICROWAVE RADIATION TEST ................................................................................................ 21
3. COMPONENT TEST PROCEDURE ............................................................................................ 22
WIRING DIAGRAM .......................................................................................................................... 23
EXPLODED VIEW AND PARTS LIST ............................................................................................. 25
1. DOOR ASSEMBLY ...................................................................................................................... 25, 28
2. CONTROL PANEL ASSEMBLY ................................................................................................... 25, 28
3. TOTAL ASSEMBLY ...................................................................................................................... 25, 28
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 allovens 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, oradjusted by procedures described in this manualbefore the
oven is released to the owner.
(e)A microwave leakage check to verify compliance with the Federal performance standardshould be performed on
each oven prior to release to the owner.

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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 ovencavity surface should be kept clean.
No grease, soil or spatter should be allowed to build up on these surfacesor inside the oven.
DO NOTATTEMPT TO OPERATE THIS APPLIANCE WITH THE DOOR OPEN.
The microwave oven has concealed switches to make sure the poweris turned off when the door isopened.
Do not attempt to defeat them.
DO NOTATTEMPT TO SERVICE THIS APPLIANCE UNTIL YOU HAVE READ THIS SERVICE MANUAL.
2. FOR SAFE SERVICE PROCEDURES
1) If the oven is operative priorto 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 immediately.
The wire in this mains lead coloured in accordance with the following code.
Green-and-yellow : Earth
Blue : Neutral
Brown : Live
As the colours of the wires in the mains lead of this appliance may not correspond with the coloured markings
identifying the terminals in your plug, proceed as follows.
The wire which is coloured green-and-yellow must be connected to the terminalin the plug which is marked with the
letter 'E', earth symbolor coloured green-and-yellow.
The wire which is coloured blue must be connected to the terminal which is marked with the letter 'N' or coloured black.
The wire which is coloured brown must be connected to the terminal whichis marked with the letter'L' or colouredred.
IMPORTANT
This oven is designed for counter-top use only.
NOTE

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SPECIFICATIONS
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SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE.
MODELKOG-3767
POWER SUPPLY 230V~50Hz, SINGLE PHASE WITH EARTHING
POWER
CONSUMPTION MICROWAVE1200W
GRILL 1050W
COMBINATION2200W
MICROWAVEENERGYOUTPUT850W
MICROWAVE FREQUENCY 2450MHz
OUTSIDEDIMENSIONS(WXH XD)
465 X279 X370 mm (18.3 X11.0 X14.6 in.)
CAVITYDIMENSIONS(WXH XD) 290 X220 X306 mm (11.4 X8.7 X12.0 in.)
NETWEIGHTAPPROX.14Kg(30.9lbs)
TIMER 60 min.DUAL SPEED
FUNCTION SELECTIONS MICROWAVE/GRILL/COMBINATION
POWER SELECTIONS 5 LEVELS
CAVITYVOLUME0.7 Cu.Ft.

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EXTERNAL VIEW
1.OUTERDIMENSION(KOG-3767/3967)
Fig1. Front viewFig2. Side view

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EXTERNAL VIEW
2. FEATURE DIAGRAM
1) Door seal - Door seal maintains the microwave energy within theoven cavity and prevents microwave leakage.
2) Reflector (Insulator Heater)
3) Heating Element
4) Oven cavity
5) Safety interlock system
6) Knob V.P.C - Used to select a microwave power level.
7) Knob timer - Used in setting cooking time for all functions.
8) Metal Rack
9) Coupler - This fits over the shaft in the center of the ovens cavity floor.
This is to remain in the oven forall cooking.
10) Roller guide - This must always be used forcooking together with the glass cooking tray.
11) Glass cooking tray- Made of special heat resistant glass.
Food in a proper receptacle is placed on this tray for cooking.
12) Door viewing screen - Allows viewing of food.
The screen is designed so that light can pass through, but not the microwave.
13) Door hook - When the door is closed, it willautomatically shut off.
If the door is opened while the oven is operating, the magnetron will immediately stop operating.

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INSTALLATION
1. Steady, flat location
This microwave oven should be set on a steady, flat surface.
This microwave oven is designed forcounter top use only.
2. Leave space behind and side
All air vents should be kept a clearance. If all vents are covered during operation, the oven may overheat and,
eventually, cause 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. Position the oven as far from them as possible.
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. Thismicrowave oven requires a current of approximately 11amperes, 230 Volts, 50 Hz.
Power supply cord is about 1.2 meters long.
• The voltage used must be the same as specified on this oven. Using a higher voltage may result in a fire or other
accident causing oven damage. Using low voltage will cause slow cooking.We are not responsible for damage
resulting from use of this oven witha voltage of ampere fuse other than those specified.
• This appliance is supplied with cable ofspecial type, which, if damaged, must be repaired with cableof same type.
Such a cable can be purchased fromDAEWOO and must be installed by a Qualified Person.
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.
7. Do not operate the ovenif it is colder than room temperature.
(This may occur during delivery in cold weather.) Allow the oven to become room temperature before operating.
This appliance must be earthed. In the event of an electrical short circuit, earthing reduces the risk of the electricshock bypro-
vidinganescape wirefor the electriccurrent.This applianceisequipped witha cord havinga earthing wirewith aearthingplug.
The plug must be plugged into an outlet that is properly installed and earthed.
Improper use ofthe earthing plug can result in a risk ofelectric shock. Consult a qualified electrician or serviceman if
the earthing instructions are not completely understood, or if doubt exists as to whether the appliance is properly
earthed, and either:
If it is necessary to use an extension cord, use only a 3-wire extension cord that has a 3-blade earthing plug, and a
3-slot receptacle that will accept the plug on the appliance.The marked rating of the extension cord should be equal
to or greater than the electricalrating of the appliance, or Do not use an extension cord.
WARNING
EARTHING INSTRUCTIONS

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OPERATIONS AND FUNCTIONS
1. Connect the main lead to an electricaloutlet.
2. After placing the food in a suitable container,
open the oven doorand put it on the glass tray.
The glass tray must always be in place during cooking.
3. Close the door securely.
4. Choose cooking power level by setting V.P.C knob to
the desired position.
Refer to cookbook for recommendedpower levels.
5. Determine cooking time. Consult cookbook for recipe timing.
Oven light turns on and cooling fan starts to operate.
Microwave cooking starts.
6. You may open the door while theoven is operating.
As soon as the door is opened, the safety mechanisms stop the
generation of microwave power and the operation ofcooking timer.
If you wish to change the time during cooking,
simply adjust the timer to the desired time.
7. When the timer reaches zero, a bell will ring and the unitwill turn off.
Oven light turns off. If additional cooking time is needed and
the door is closed, the oven will automatically start when the timer is reset.
• To set MICROWAVE cooking
Set the variable power selector to the desired power level.
• To set GRILL cooking
Set the POWER SELECTOR to the (grill) position.
• To set COMBI cooking
Set the POWER SELECTOR to the (combi) position.
POWER LEVEL SYMBOL
APPROXIMATE PERCENTAGE OF POWER
KOG-3767 KOG-3967
HIGH MAX MAX 100 %
MED-HIGH 750W 840W 88 %
MEDIUM 620W 690W 73 %
DEFORST 41 %
HEAT 26 %
When using the GRILL or COMBI mode;
•
Do notopen the door so often,the temperature inside the oven decrease and the cooking may notbe completed in setting time.
•
Never touch the oven window andmetal interiorof the oven when taking food in andout, because the temperature inside
the ovenand door is very high.
•
When using these modes, be careful as the tray will be hot to touch, use oven gloves or pot holders while handling tray.
NOTE
1. When setting timer for less than 2 minutes, turn the
timer past 2 minutes and then return to the correct
timer setting.
2. Various clicking noises may be heard when turning
V.P.C knob. This is normal and does not affect the
operation of yourmicrowave oven.
NOTE

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DISASSEMBLY ANDASSEMBLY
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 observethe following precautions carefully.
1. Always remove the powerplug 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 earthed.
Do not operate on a two-wire extension cord.
The microwave oven is designed to be used while earthed.
It is imperative, therefore, to makes 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 has stopped an electric
charge remains in the high voltage capacitor.
When replacing or checking parts, shortbetween 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 due to the operation of the monitor
switch; replace primary interlock switch, secondary interlock
switch and interlock monitor switch.
5. After repair or replacementof parts, make sure that the screws are
properly tightened, and all electrical connections are tightened.
6. Do not operate without cabinet.
Service personnel should remove their watches whenever working close to or replacing the magnetron.
CAUTION
When servicing the appliance, take a 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, HV Diode, HV Fuse.
WARNING

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DISASSEMBLY ANDASSEMBLY
1. To remove cabinet
(1) Remove three screws on cabinet back.
(2) Push the cabinet backward.
2. To remove door assembly
(1) Remove a screw which securethe stopper hinge top.
(2) Remove the door assembly fromtop plate of cavity.
(3) Reverse the above steps for reassembly.
After replacing the door assembly, perform a check of correct alignment with the hinge and cavity frontplate.
CAUTION