GOLDSTAR MV1604ST Service Manual

website: http://us.lgservice.com

MICROWAVE OVEN

SERVICE MANUAL

MODEL : MV1604ST

CAUTION

BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

P/NO : 3828W5S4067

May, 2004

Printed in Korea

CAUTION

SAFETY PRECAUTIONS

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 microwave power 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.

• Proper operation of the microwave ovens requires that the magnetron be assembled to the wave guide and cavity. Never operate the magnetron unless it is properly installed.

• Be sure that the magnetron gasket is properly installed around the dome of the tube whenever installing the magnetron.

• Routine service safety procedures should be exercised at all times.

• Untrained personnel should not attempt service without a thorough review of the test procedures and safety information contained in this manual.

FOREWORD

Read this Manual carefully. Failure to adhere to or observe the information in this Manual may result in exposing yourself to the Microwave Energy normally contained within the oven cavity.

TABLE OF CONTENTS

(Page)

SAFETY PRECAUTIONS

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Inside front page

SPECIFICATIONS

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1-1

CAUTIONS

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2-1

INSTALLATIONS

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3-1

OPERATING INSTRUCTIONS

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4-1

CONTROL PANEL

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4-1

CONTROL PANEL INSTRUCTIONS

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4-2

OVERALL CIRCUIT DIAGRAM

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5-1

SCHEMATIC DIAGRAM

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5-1

MATRIX CIRCUIT FOR TOUCH KEY BOARD

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5-2

GENERAL INFORMATION FOR SERVICE

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6-1

GENERAL PRECAUTIONS IN USE

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6-1

TRIAL OPERATION

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6-1

FEATURES AND SPECIFICATIONS FEATURES

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6-1

SERVICE INFORMATION

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7-1

PRECAUTIONS AND REPAIR SERVICE TIPS

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7-1

MICROWAVE LEAKAGE TEST

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7-2

POWER OUTPUT MEASUREMENT

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7-3

DISASSEMBLY INSTRUCTIONS

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7-4

INTERLOCK SYSTEM

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7-12

INTERLOCK CONTINUITY TEST

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7-14

TEST AND CHECKOUT PROCEDURES AND TROUBLE SHOOTING

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7-15

A. TEST PROCEDURES

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7-15

B. CHECKOUT PROCEDURES

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7-18

C. TROUBLE SHOOTING

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7-21

EXPLODED VIEW

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8-1

REPLACEMENT PARTS LIST

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9-1

1-1

Rated Power Consumption

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1,500W maximum (Microwave oven+Cook top lamps+Ventilation fan)

Frequency

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2,450 MHz ± 50 MHz

Power Supply

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120 VAC, 60 Hz

Rated Current

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13 Amp. (Microwave oven+Cook top lamp+Ventilation fan)

Magnetron Cooling

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Forced Air Cooling

Rectification

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Rectification Voltage Double Half-Wave

Door Sealing

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Choke System

Safety Devices

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Oven Cavity Thermostat:

Open at 90°C ± 5°C Fuse(20A) Primary Interlock Switch Secondary Interlock Switch Interlock Monitor

Magnetron

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2M214-161GP

High Voltage Capacitor

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Capacitor: 1.0µF, 2.1 KV AC

High Voltage Diode

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Diode; 350mA, 9.0 KV

Cook top Lamp

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125 V, 30 W

Cavity Lamp

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125 V, 30 W

Timer

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Digital, up to 99 mim. 99 sec. (in each cooking stage)

Tray

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Tempered Safety Glass

Overall Dimensions

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2915/16"(W)x167/16"(H)x153/8"(D)

Oven Cavity Size

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/16"(W)x83/4"(D)x14 1/8"(H)

Effective Capacity of Oven Cavity

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1.6 Cu.ft.

Accessories

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Owner’s Manual & Cooking Guide, Installation Manual, Exhaust Adapter, Exhaust Damper, Mounting Kit and Two Filters, Rotating Ring Assembly.

SPECIFICATIONS

2-1

• DO NOT operate on a 2-wire extension cord during repair and use.

• NEVER TOUCH any oven components or wiring during operation.

• BEFORE TOUCHING any parts of the oven, always remove the power plug from the outlet.

• For about 30 seconds after the oven stops, an electric charge remains in the high voltage capacitor. When replacing or checking, you must discharge the high voltage capacitor by shorting across the two terminals with an insulated screwdriver.

• Remove your watches whenever working close to or replacing the Magnetron.

• DO NOT touch any parts of the control panel circuit. A resulting static electric discharge may damage this P.C.B.

• NEVER operate the oven with no load.

• NEVER injure the door seal and front plate of the oven cavity.

• NEVER put iron tools on the magnetron.

• NEVER put anything into the latch hole and the interlock switches area.

• Proper operation of the microwave oven requires that the magnetron be assembled to the waveguide and cavity. Never operate the magnetron unless it is properly installed.

• Be sure that the magnetron gasket is properly

installed around the dome of the tube whenever installing the magnetron.

CAUTIONS

Unlike other appliances, the microwave oven is high-voltage and high-current equipment. Though it is free from danger in ordinary use, extreme care should be taken during repair.

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 connection. All input and output microwave connections, waveguide, flange, and gasket must be secure never operate the device without a microwave energy absorbing load attached. Never look into an open waveguide or antenna while the device is energized.

THE OVEN IS TO BE SERVICED ONLY BY PROPERLY QUALIFIED SERVICE PERSONNEL.

ANTENNA

Gasket

COOLING FIN MAGNETRON CHASSIS GROUND

FILAMENT

TERMINALS

MAGNETRON

3-1

PRECAUTIONS ON INSTALLATION

A. Plug the power supply cord into a 120V AC, 60Hz,

single-phase power source with a capacity of 15A or 20A.

B. Avoid placing the unit in a location where there is

direct heat or splashing water. C. Install the unit on the mounting plate firmly. D. Place the unit as far away as possible from TV,

radio, etc. to prevent interference.

GROUNDING INSTRUCTIONS

For personal safety, this appliance must be fully grounded at all times.

In the event of an electrical short circuit, grounding reduces the risk of electrical shock. The plug must be plugged into an outlet that is properly installed and grounded.

INSTALLATIONS

BEFORE YOU BEGIN, READ THE FOLLOWING INSTRUCTIONS COMPLETELY AND CAREFULLY.

CAUTION

This unit is equipped with a 3-prong plug for your

safety. If the wall outlet is a grounded 3-hole type,

the unit will be grounded automatically.

WARNING

Improper use of the grounding plug can result in

a risk of electric shock.

Do not, under any circumstances, cut or remove

the third ground prong from the power cord plug.

Properly Polarized and Grounded Outlet

Plug with Ground Prong

4-1

OPERATING INSTRUCTIONS

CONTROL PANEL

NOTE: Styling and features vary by model.

4-2

1. DISPLAY: The Display includes a clock and indicators to

tell you time of day, cooking time settings and cooking functions selected.

2. POPCORN: Touch this pad when popping popcorn in

your microwave oven.

3. PIZZA: Touch this pad to reheat 1 to 3 slices.

4. COOK: Touch this pad to cook vegetables, rice, or

casseroles.

5. POTATO: Touch this pad to cook potatoes from 1 to 4ea.

6. VEGETABLE: Touch this pad to cook vegetables. The

oven’s sensor will tell the oven how long to cook depending on the amount of humidity it detects from the vegetables.

7. REHEAT: Touch this pad to reheat a dinnerplate,

soup/sauce, casserole.

8. MORE: Touch this pad to add ten seconds of cooking

time each time you press it.

9. CUSTOM COOK: Touch this pad to recall one cooking

instruction previously programmed into memory.

10. LESS: Touch this pad to subtract ten seconds of cooking

time each time you press.

11. AUTO DEFROST: Meat, poultry, fish. Touch on pad to

select food type and defrost food by weight.

12. EZ ON: Touch this pad to set and start quickly at 100%

power level.

13. NUMBER: Touch number pads to enter cooking time, power level, quantities or weights.

14. CUSTOM SET: Touch this pad to change the oven’s default settings for sound, clock, display speed and defrost weight.

15. CLOCK: Touch this pad to enter the time of day.

16. HOLD WARM: Touch this pad to keep hot, cooked foods

safety warm in your microwave oven for up to 99 minutes 99 seconds.

17. TIME COOK: Touch this pad to set a cooking time.

18. POWER LEVEL: Touch this pad to select a cooking

power level.

19. STOP/CLEAR: Touch this pad to stop the oven or clear all entries and engage or disengage the child lock.

20. START: Touch this pad to start a function. If you open the door after oven begins to cook, retouch start.

21. KITCHEN TIMER: Touch this pad to set the kitchen timer without operating the oven.

22. TURNTABLE ON/OFF: Touch this pad to turn off the turntable. “OFF” will appear in the display.

23. LIGHT TIMER: Touch this pad to set the light timer.

24. FAN HI/LOW/OFF: Touch this pad to turn the fan on or

off.

25. LIGHT HI/LOW/OFF: Touch this pad to turn on the cooktop/countertop light.

CONTROL PANEL INSTRUCTIONS

NOTE: Styling and features vary by model.

5-1

OVERALL CIRCUIT DIAGRAM

SCHEMATIC DIAGRAM

5-2

MATRIX CIRCUIT FOR TOUCH KEY BOARD

COOK

LEVEL

POWER

N.C

STOP/

CLEAR

POPCORN

CUSTOM

SET

FAN

HI/LOW/OFF

COOK

WARM

HOLD

REHEAT

N.C

LIGHT

TIME

CUSTOM

TIMER

START

AUTO

DEFROST

TIMER

KITCHEN

N.C

CLOCK

VEGETABLE N.C

MORE LESS

POTATO

PIZZA

N.C

LIGHT

N.C

EZ-ON

6 7

N.C

HI/LOW/OFF

N.C N.C

TURNTABLE

ON/OFF

6-1

GENERAL PRECAUTIONS IN USE

A. Never operate the unit when it is empty.

Operating the oven with no load may shorten the life of the magnetron. Whenever cooking dry foods (dried fish, bread, etc.) or a small amount of food, be sure to put a glass of water into the cooking compartment. The glass turntable may become hot after operating, be careful when touching it.

B. Aluminum foil should be avoided because it will

disrupt cooking and may cause arcing. However, small pieces may be used to cover some parts of food to slow the cooking. Any aluminum foil used should never be closer than 2.5 cm to any side wall of the oven.

TRIAL OPERATION

After installation, the following sequences and results should be checked carefully.

A. Put a container filled with water (about 1 liter) into

the oven, and close the door tightly.

B. Set cooking time for 10 minutes by touching “1” and

then “0” three times. “1, 0, 0, 0” appears in the display window.

C. Touch the START key.

Make sure the cavity light comes on. The unit will begin cooking and the display window will show the time counting down by seconds.

D. After about 5 minutes, make sure the primary

interlock switch, the secondary interlock switch and the interlock monitor switch operate properly by opening and closing the door several times. Touch the START key each time the door is closed.

E. Continue operating the unit. Four long beep sound

signal is heard when the time is up. The unit will

shut off automatically. F. Confirm the water is hot. G. Finally, measure the output power according to

“POWER OUTPUT MEASUREMENT” on page 7-3.

FEATURES AND SPECIFICATIONS FEATURES

A. The safety systems incorporated in this model are:

(1) Primary interlock switch (2) Secondary interlock switch (3) Interlock monitor switch (4) Choke system (5) Magnetron thermal fuse (6) Oven cavity thermostat

(Note: This thermostat located on the oven cavity will open and stop the unit from operation only if a high temperature is reached, such as, a fire created by overcooking food.)

B. Any one of 10 power output levels ranging 100W to

1000W can be selected by the touch control and electronic computer system.

GENERAL INFORMATION FOR SERVICE

7-1

PRELIMINARY

A. SINCE NEARLY 2,100 VOLTS EXISTS IN SOME

CIRCUITS OF THIS UNIT REPAIRS SHOULD BE CARRIED OUT WITH GREAT CARE.

The filament leads of magnetron carry High Voltage with respect to ground. Extreme caution must be exercised. Never plug the unit into a power source to determine which component is defective in high voltage section.

B. TO AVOID POSSIBLE EXPOSURE TO

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

(1) Before the power is applied:

(a) Make sure the primary interlock switch, the

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

(b) Make sure the perforated screen and the

dielectric choke of the door are correctly and firmly mounted.

(2) After power is applied:

(a) Make sure the interlock switch mechanism is

operating properly by opening and closing the door.

(b) Check microwave energy leakage must

bebelow the limit of 5 mW/cm2. (All service adjustments should be made for minimum microwave energy leakage readings).

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

repaired, if any of the following conditions exist. The unit must not be operated. (a) The door does not close firmly. (b) The hinge is broken. (c) The door seal is damaged. (d) The door is bent or warped, or there is any

other visible damage on the unit that may

cause microwave energy leakage. NOTE: Always keep the seal clean. (e) Make sure that there are no defective parts in

the interlock mechanism. (f) Make sure that there are no detective parts in

the microwave generating and transmission assembly (especially waveguide).

(4) The following items should be checked after the

unit is repaired: (a) The interlock monitor switch is connected

correctly and firmly. (b) The magnetron gasket is properly positioned

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

(no microwave energy leakage)

(d) The door can be properly closed and the

safety switches work properly.

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

the time is up.

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

SERVICE INFORMATION

PRECAUTIONS AND REPAIR SERVICE TIPS

7-2

CAUTIONS

• Be sure to check microwave leakage prior to servicing the oven if the oven is operative prior to servicing.

• The service personnel should inform the manufacture importer, or assembler of any certified oven unit found to have a microwave emission level in excess of 5 mW/cm2and should

repair any unit found to have excessive emission levels at no cost to the owner and should ascertain the cause of the excessive leakage. The service personnel should instruct the owner not to use the unit until the oven has been brought into compliance.

• If the oven operates with the door open, the service personnel should:

- Tell the user not to operate the oven.

- Contact the manufacturer and CDRH

(Center for Devices and Radiological Health) immediately.

NOTE: Address on CDRH

Office of Compliance(HFZ-312) Center for Devices and Radiological Healthe 1390, Piccard Drive, Rockville. MD 20850

• The service personnel should check all surface and vent openings for microwave leakage.

• Check for microwave leakage after every servicing. The power density of the microwave radiation leakage emitted by the microwave oven should not exceed 4 mW/cm2. Always start measuring of an unknown field to assure safety for operating personnel from radiation leakage.

EQUIPMENT

• TESTER (VOLTS-DC, AC, Ohmmeter)

• Microwave survey meter

- Holaday HI-1500

HI-1501

- Narda 8100

8200

• 600 cc non conductive material beaker (glass or plastic), inside diameter: approx. 8.5 cm (3 1/2in.)

• Glass thermometer: 100°C or 212°F (1 deg scale)

MEASURING MICROWAVE ENERGY LEAKAGE

• Pour 275±15cc of 20±5°C(68±9°F) water in a beaker which is graduated to 600 cc, and place the beaker on the center of the turntable.

• Set the energy leakage monitor to 2,450 MHz and use it following the manufacturer's recommended test procedure to assure correct result.

• When measuring the leakage, always use the 2inch (5cm) spacer supplied with the probe.

• Operate the oven at its maximum output.

• Measure the microwave radiation using and electromagnetic radiation monitor by holding the probe perpendicular to the surface being measured.

Move probe along shaded area.

Probe scanning speed Less than 2.5 cm/sec. ( 1 in/sec)

MICROWAVE LEAKAGE TEST

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