Goldstar MV-1155W Service Manual

Website: http://biz.lgservice.com

MICROW AVE OVEN

SER VICE MANUAL

MODEL : MV-1155W

CAUTION

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

P/NO : 3828W5S0807

Printed in Korea

CAUTION

WARNING TO SERVICE TECHNICIANS

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 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 performanc 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.

— 1 —

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.

MECHANICAL SERVICE INFORMATION

TABLE OF CONTENTS

ADJUSTMENT PROCEDURES ................................................................................................................................... 3

PRECAUTIONS ON INSTALLATION ........................................................................................................................... 5

GENERAL PRECAUTIONS IN USE ............................................................................................................................ 5

TRIAL OPERATION ..................................................................................................................................................... 5

FEATURES AND SPECIFICATIONS ........................................................................................................................ 5-6

OVERALL CIRCUIT DIAGRAM ................................................................................................................................ 7-8

OPERATING PROCEDURES ................................................................................................................................. 9-10

PROCEDURE FOR MEASURING MICROWAVE ENERGY LEAKAGE .............................................................. 11-12

DISASSEMBLY INSTRUCTIONS ......................................................................................................................... 13-20

PRECAUTIONS AND REPAIR SERVICE TIPS ......................................................................................................... 21

TEST AND CHECKOUT PROCEDURES, AND TROUBLESHOOTING

A. TEST PROCEDURES ................................................................................................................................ 22-28

B. CHECKOUT PROCEDURES ..................................................................................................................... 28-30

C. TROUBLESHOOTING ............................................................................................................................... 31-36

EXPLODED VIEW.................................................................................................................................................. 37-45

REPLACEMENT PARTS LIST......................................................................................................................... 46-54

SCHEMATIC DIAGRAM OF PCB......................................................................................................................... 55

PRINTED CIRCUIT BOARD ................................................................................................................................. 56

PCB PARTS LIST ............................................................................................................................................ 57-59

— 2 —

1. ADJUSTMENT PROCEDURES

ADJUST THE LATCH AND SWITCH CLOSING

To avoid possible exposure to microwave energy leakage, adjust the door latches and interlock switches, using the following procedure.

ONLY AUTHORIZED SERVICE PERSONNEL SHOULD MAKE THIS ADJUSTMENT.

The Interlock Monitor and Secondary Interlock Switch act as the final safety switch protecting the user from microwave energy. The terminals between "COM" and "NC" of the Interlock Monitor switch must close when the door is opened. After adjusting the Interlock Monitor Switch make sure that it is correctly connected. See Figures 1-a and 1-b throughout this procedure.

CHECK THE DOOR LATCH AND SWITCH CLOSINGS.

NOTE: The outer cover of the microwave oven is

removed.

(1) Set the microwave oven on its side so that you can

see the latch board and the switches, as shown in Figure 1-a.

(2) Close the door tightly and check gaps A and B to be

sure they are no more than 1/64" (5 mm). See Figure 1-b for close-up view of gaps A and B (door latches).

If all gaps are less than 1/64" (5 mm), adjustment of the latch board may not be necessary. Go to Steps 5 and 6 to check the sequence of the switches.

NOTE: To correct sequence of the Primary Interlock Switch, Secondary Interlock Switch and the Interlock Monitor Switch is very important.

If any gap is larger than 1/64" (5 mm), you will need to adjust the latch board-U, L. Go to step 3 and follow all steps in order.

(3) Loosen the two screws holding the plastic latch

board as shown.

(4) With the oven door closed tightly, move the latch

board upward toward the top of the oven and/or away from the door latch until the gaps are less than 1/64" (5 mm). Hold the latch board tigtly in this position until you check the sequence of the switches in steps 5 and 6.

TEST THE LATCH AND SWITCH SEQUENCE

(5) Open the oven door slowly. Watch the door latch, the

Secondary Switch. Release Rod and Lever on the switches to make sure they are zero to the body of the switches in the following sequence:

— Primary Interlock Switch — Secondary Interlock Switch — Interlock Monitor Switch

Adjust the latch board until the switches operate in this sequence. See Steps 3 and 4.

(6) Close the oven door slowly and be sure it is tightly

closed. Watch the three switches to make sure they are zero to the body of the switches in the following sequence:

— Interlock Monitor Switch — Primary Interlock Switch — Secondary Interlock Switch

NOTE: The Interlock Monitor Switch is an added safety check on the Primary and Secondary Interlock Switches. If the Primary and Secondary Interlock Switches allow the oven to operate with the door open, the Monitor Switch will blow the fuse.

(7) When you achieve the proper sequence of swithces

in Steps 5 and 6, tighten the latch board screws at that point.

TEST THE MICROWAVE ENERGY LEAKAGE

(8) Using a survey meter, make sure the microwave

energy is below 4 mW/cm2.

— 3 —

Latch Board

Secondary Interlock Switch

Oven Lamp Switch

Interlock Monitor Switch

Primary Interlock Switch

Figure 1-a

Latch

0.1/64"

— 4 —

2. PRECAUTIONS ON INSTALLATION (Figure 2)

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

single-phase power source with a capacity of at least 15 amperes.

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.

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

Plug with Ground Prong

Properly Polarized and Grounded Outlet

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

oven, and close the door tightly. B. Touch the STOP/CLEAR and the TIME keys. C. Set cooking time for 10 minutes by touching "1" and

then "0" three times. "1, 0, 0, 0" appears in the

display window. D. 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. E. After about 5 minutes, make sure the primary

interlock switch, the secondary interlock switch and

the interlock monitor and oven lamp switch operate

properly by opening and closing the door several

times.

Touch the START key each time the door is closed. F. Continue operating the unit. Two short and a long

beep sound signal is heard when the time is up.

The unit will shut off automatically. G. Confirm the water is hot. H. Finally, measure the output power according to

"POWER OUTPUT MEASUREMENT" on page 12.

5. FEATURES AND SPECIFICATIONS

Figure 2

3. 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 ceramic plate 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 part of food to slow the cooking. Any aluminum foil used should never be closer than 2.5cm to any side wall of the oven.

C. Be sure to insert the temperature probe into the food

and the other end into the socket in the cooking cavity for the temperature controlled cooking.

4. TRIAL OPERATION

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

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 thermostat

(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 85W to

850W can be selected by the touch control and

electronic computer system. C. The temperature probe enables accurate control of

cooking temperature and results. D. Cooking time, power output level and operating

temperature can be displayed on the digital readout. E. Three different cooking stages can be set. The oven

remembers three cooking stages and changes from

one cooking stage to another. This is made possible

with the memory function of the microprocessor. This

cooking process can be set after Auto Defrost is set.

— 5 —

SPECIFICATIONS

Rated Power Consumption ................................. 1300W maximum (Microwave oven only)

1500W maximum (Microwave oven+Cook top lamps+Ventilation fan) 1500W (Convection)

Microwave Output ............................................... 850W (IEC 705 TEST PROCEDURE)

Adjustable 85W through 850W, 10 steps

1350W (Convection)

Frequency ........................................................... 2,450 MHz±50 MHz

Power supply ....................................................... 120V ±12V AC, 60Hz

Rated Current ...................................................... 12 Amp. (Microwave oven only)

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

Magnetron Cooling .............................................. Forced Air Cooling

Microwave Stirring ............................................... Stirrer Fan Disk

Rectification ......................................................... Rectification Voltage Doubler Half-Wave

Door Sealing ....................................................... Choke System

Safety Devices .................................................... Magnetron Thermostat:

Open at 150°C±6°C Close at 60°C±15°C

Oven Thermostat:

Open at 150°C±6°C

Close at below 0°C Fuse(15A) Primary Interlock Switch Secondary Interlock Switch Interlock Monitor

Magnetron ........................................................... 2M214-19F

High Voltage Capacitor ....................................... Capacitor: 0.91μFd, 2.1KV Ac

High Voltage Diode ............................................. Diode; 350mA, 9.0KV

Cook top Lamp .................................................... 125V, 30W

Cavity Lamp ........................................................ 125V, 30W

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

Tray ..................................................................... Ceramic Plate

Overall Dimensions ............................................. 29

Oven Cavity Size ................................................. 18

Effective Capacity of Oven Cavity ....................... 1.1 Cu.ft.

Accessories ......................................................... Use and Care Manual, Installation Manual,

/8"(W)x14"(D)x163/16"(H)

/16"(W)x125/8"(D)x85/32"(H)

Metal Rack, Exhaust Adapter, Exhaust Damper, Mounting Kit and Two filters.

SWITCH CHART

PRIMARY SECONDARY INTERLOCK

SWITCH MODE INTERLOCK INTERLOCK MONITOR

SWITCH SWITCH SWITCH

CONDITIONS

DOOR OPEN DOOR CLOSED

NOTE: Use the above switch chart with circuit diagram on page 7.

COM COM COM

NO NO NC

··

— 6 —

6. OVERALL CIRCUIT DIAGRAM

A. SCHEMATIC DIAGRAM

— 7 —

B. MATRIX CIRCUIT FOR TOUCH KEY BOARD

N.C

HOLD

WARM

LIGHT

OFF

AUTO

COMBI.

CONV.

BAKE

CONV.

BROIL

COMBI.

BAKE

COMBI.

ROAST

FAN

HIGH

FAN

LOW

FAN OFF

LIGHT

HIGH

LIGHT

NIGHT

ROOM

TEMP

FROZEN

TEMP

POULTRY

CUSTOM

COOK

SENSOR

COOK

SENSOR

POPCORN

STOP

/CLEAR

N.CN.C

N.C

CLOCK

POWER

START

TIME

FISH

MEAT

N.C

Figure 3

— 8 —

B. MATRIX CIRCUIT FOR TOUCH KEY BOARD

N.C

HOLD

WARM

LIGHT

OFF

AUTO

COMBI.

CONV.

BAKE

CONV.

BROIL

COMBI.

BAKE

COMBI.

ROAST

FAN

HIGH

FAN

LOW

FAN OFF

LIGHT

HIGH

LIGHT

NIGHT

ROOM

TEMP

FROZEN

TEMP

POULTRY

CUSTOM

COOK

SENSOR

COOK

SENSOR

POPCORN

STOP

/CLEAR

N.CN.C

N.C

CLOCK

POWER

START

TIME

FISH

MEAT

N.C

Figure 3

— 8 —

7. OPERATING PROCEDURES

Figure 4

Display -

Used to show time of day, cooking time, cooking power level, and miscellaneous indicators during cooking functions.

Popcorn -

Used to pop popcorn.

Cook -

Used to sensor cooking.

Room Temp -

Used to reheat foods at room temperature.

Frozen Temp -

Used to reheat frozen foods.

Convection -

Used in setting convection cooking or preheat.

Combination -

Used in setting combination cooking or preheat.

Auto Combination -

Used in setting weight combination cooking.

Time -

Used in setting cooking time.

Power -

Used to select cooking power.

Clock -

Used in setting time of day.

Custom Cook -

Used for memory entry and memory recall of a cooking program.

Numbers -

Used to enter the:

• Time of day

• Cooking Time

• Cooking Powers

• Quantities or weights

Hold Warm -

Used to keep hot, cooked foods safely warm in your microwave oven up to 60 minutes.

Auto Defrost -

Used to defrost frozen meat, poultry, and fish.

Fan Control Pad -

Used to turn on the fan at high speed or low speed and turn off the fan.

Light Pad -

Used to turn the work light on/off in either the high or night modes.

Stop/Clear -

Used to stop the oven or clear all entries except time of day.

Start -

Used to start the oven.

HOLD

WARM

CLOCK

CUSTOM

COOK

TIME POWER

123 456 7

POPCORN COOK

ROOM

TEMP

FROZEN

TEMP

SENSOR

CONVECTION

COMBINATION

BAKE BROIL

BAKE

AUTO COMBI

ROAST

STOP

CLEAR

START

MEAT

POULTRY

FISH

HIGH LOW OFF

HIGH NIGHT OFF

AUTO DEFROST

FAN

LIGHT

A. OVEN CONTROL PANEL

— 9 —

B. PANEL INSTRUCTIONS (Figure 4)

The entire operation is done by simple touch control pads.

(1) Display Window

Numbers and letters explained in Figure 4 are shown in the display window (Vacuum Fluorescent Tube).

The Time of Day in five-digits (12-hour indication):

(a) (b) Cooking Time in five digits. (c) Power Control Level in two digits. (d) Food Temperature (Doneness Temperature) in

five digits.

(e) Each Indicator Light shows which function is set

and involved in the course of cooking by turning itself on. Indicator Lights automatically go out upon completion of cooking.

(6) START Key

Touch the START key after setting the desired cooking time etc. Also touch the START key to resume cooking after the cooking is temporarily stopped by opening the door. The key will not function unless the door is closed.

(7) SENSOR Key

Used to sensor cooking.

(8) CONVECTION Key

Used in setting convection cooking or preheat.

(2) TIME Key

The TIME key is used to set the microwave cooking time. Touch the TIME key and then number keys that correspond to the desired cooking time. The remaining time is continuously displayed during cooking.

(3) POWER Key

Used to select cooking power level.

(4) CLOCK Key

Used in setting Time of Day.

(5) STOP/CLEAR Key

Used to stop the oven or clear all entries except Time of Day.

(9) COMBINATION Key

Used in setting combination cooking or preheat.

(10) AUTO COMBINATION Key

Used in setting weight combination cooking.

(11) AUTO DEFROST Key

Used to defrost for frozen foods by weight.

— 10 —

8. PROCEDURE FOR MEASURING

Move probe along shaded area.

Probe scanning speed less than 2.5cm/sec.

MICROWAVE ENERGY LEAKAGE

A. CAUTIONS

(1) Be sure to check a microwave emission prior to

servicing the oven if the oven is operative prior to servicing.

(2) The service personnel should inform the

manufacturer, importer or assembler of any certified oven unit found to have a microwave emission level in excess of 4 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.

(3) 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 Health 1390 Piccard Drive Rockville, Marryland 20850

(4) The service personnel should check all surface and

vent openings for microwave emission testing.

(5) Check for microwave energy leakage after every

servicing. The power density of the microwave radiation leakage emitted by the microwave oven should not exceed 4 mW/cm2. And always start measuring of an unknown field to assure safety for operating personnel from radiation leakage. NOTE: The standard is 5 mW/cm2. while in the customer's home. 4 mW/cm2. stated here is manufactruer's own voluntary standard for units in customer's home.

EQUIPMENT

●

Electromagnetic energy leakage monitor (NARDA 8100B, HOLADAY HI-1501).

●

600cc glass beaker.

●

Glass thermometer 100°C.

B. MEASURING MICROWAVE ENERGY LEAKAGE

(1) Pour 275±15cc of 20±5°C water in a beaker which

is graduated to 600cc, and place the beaker in the center of the oven.

(2) Set the energy leakage monitor to 2,450MHz and

use it following the manufacturer's recommended test procedure to assure correct result.

(3) When measuring the leakage, always use the 2 inch

(5cm) spacer supplied with the probe. (4) Operate the oven at its maximum output. (5) Measure the microwave radiation using and

electromagnetic radiation monitor by holding the

probe perpendicular to the surface being measured.

Figure 6

C. MEASUREMENT WITH THE OUTER CASE

REMOVED

(1) When you replace the magnetron, measure for

microwave energy leakage before the outer case is installed and after all necessary components are replaced or adjusted. Special care should be taken in measuring the following parts.

— Around the magnetron — The waveguide

WARNING: AVOID CONTACTING ANY HIGH

VOLTAGE PARTS.

Figure 5

— 11 —

D. MEASUREMENT WITH A FULLY

Water Load

Ceramic Plate

Figure 7

ASSEMBLED OVEN

(1) After all components, including the outer panels, are

fully assembled, measure for microwave energy leakage around the door viewing window, the exhaust opening and air inlet openings.

(2) Microwave energy leakage must not exceed the

values prescribed below.

NOTES:

Leakage with the outer panels removed-less than 5mW/cm2. Leakage for a fully assembled oven ("Before the latch switch (primary) is interrupted") with the door in a slightly opened position-less than 2mW/cm2.

E. NOTE WHEN MEASURING

(1) Do not exceed meter full scale deflection. (2) The test probe must be removed no faster than 1

inch/sec (2.5 cm/sec) along the shaded area, otherwise a false reading may result.

(3) The test probe must be held with the grip portion of

the handle. A false reading may result if the operator's hand is between the handle and the probe.

(4) When testing near a corner of the door, keep the

probe perpendicular to the surface making sure the probe horizontally along the oven surface, this may possibly cause probe damage.

G. POWER OUTPUT MEASUREMENT

(1) 1. Fill two test bowls with each 59°F (15°C)-

75°F(24°C) 1 liter water respectively.

2. Use accurate thermometer (°F or °C) and measure each water temperature repsectively.

(2) Place the two bowls on ceramic plate. (3) 1. Set cooking time to 2 minutes. ("2 00" appears in

display)

2. Touch START key and operate oven for exactly 2 minutes.

(4) 1. Take out the two bowls at once.

2. Stir both water with thermometer and measure the water temperature rise respectively.

(5) 1. Get temperature rise by calculating the difference

(water temperature after cooking minus initial temperature) in each test bowls.

2. Then calculate average value of both temperature rises in degrees Fahrenheit (°F) or Centigrade (°C).

(6) Power output shall be indicated by the following

ranges of water temperature rise as shown in the chart below.

(7) Power Output will be influenced by line voltage of

power supply. Consequently, correct power output must be measured within 120V AC ±1 volt while unit is operating.

Average

Temp. Rise

108V (Low Voltage)

Temp. Rise

F. RECORD KEEPING AND NOTIFICATION AFTER

MEASUREMENT

(1) After adjustment and repair of any microwave energy

interruption or microwave energy blocking device, record the measured values for future reference. Also enter the information on the service invoice.

(2) Should the microwave energy leakage not be more

than 2 mW/cm2after determining that all parts are in good condition, functioning properly and genuine replacement parts which are listed in this manual have been used.

(3) At least once a year, have the electromagnetic

energy leakage monitor checked for calibration by its manufacturer.

Min. Max. Min.

16.2°F 22.1°F 16.2°F

(9.0°C) (12.3°C) (9.0°C)

— 12 —

9. DISASSEMBLY INSTRUCTIONS

Circuit Board

Screw

Figure 8

Figure 9

FPC Connector ( S1)

Circuit Board

Control Base

Figure 7

Control Panel

Power Trans

Connector

Relay 2 Relay 9

Screw

(CN 4)

(CN 2)

(CN 1)

IMPORTANT NOTES:

UNIT MUST BE DISCONNECTED FROM ELECTRICAL OUTLET WHEN MAKING REPAIRS, REPLACEMENTS, ADJUSTMENTS AND CONTINUITY CHECKS. WAIT AT LEAST ONE MINUTE, UNTIL THE HIGH VOLTAGE CAPACITOR IN THE HIGH VOLTAGE POWER SUPPLY HAS FULLY DISCHARGED. THE CAPACITOR SHOULD BE DISCHARGED BY USING INSULATED WIRE-I.E. TEST PROBE CONNECTED TO 10K-OHM RESISTOR IN SERIES TO GROUND. WHEN RECONNECTING THE WIRE LEADS TO ANY PART, MAKE SURE THE WIRING CONNECTIONS AND LEAD COLORS ARE CORRECTLY MATCHED ACCORDING TO THE OVERALL CIRCUIT DIAGRAM. (ESPECIALLY SWITCHES AND HIGH VOLTAGE CIRCUIT.)

A. REMOVING POWER AND CONTROL CIRCUIT

BOARD (Figure 7, 8 and 9)

(1) Remove 1 screw securing the control panel

assembly to the oven cavity. (Figure 7) (2) Remove the control panel with pushing it upward. (3) Remove the three connectors (CN1, CN2, CN4) and

wire leads (Relay) from the circuit board. (4) Remove 5 screws securing the circuit board.

(Figure 8) (5) Remove the FPC connector from the terminal socket

following "HOW TO REMOVE THE FPC

CONNECTOR" on the next page. (6) Remove the circuit board from the control bracket

carefully.

— 13 —

+ 33 hidden pages