GOLDSTAR MV1604ST Service Manual

Page 1
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
Printed in Korea
Page 2
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.
Page 3
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
----------------------------------------------------------------------------------------------------
Inside front page
SPECIFICATIONS
--------------------------------------------------------------------------------------------------------------------------------
1-1
CAUTIONS
------------------------------------------------------------------------------------------------------------------------------------------
2-1
INSTALLATIONS
----------------------------------------------------------------------------------------------------------------------------------
3-1
OPERATING INSTRUCTIONS
----------------------------------------------------------------------------------------------------------------
4-1
CONTROL PANEL
-------------------------------------------------------------------------------------------------------------------------
4-1
CONTROL PANEL INSTRUCTIONS
------------------------------------------------------------------------------------------------
4-2
OVERALL CIRCUIT DIAGRAM
---------------------------------------------------------------------------------------------------------------
5-1
SCHEMATIC DIAGRAM
-----------------------------------------------------------------------------------------------------------------
5-1
MATRIX CIRCUIT FOR TOUCH KEY BOARD
-----------------------------------------------------------------------------------
5-2
GENERAL INFORMATION FOR SERVICE
-----------------------------------------------------------------------------------------------
6-1
GENERAL PRECAUTIONS IN USE
-------------------------------------------------------------------------------------------------
6-1
TRIAL OPERATION
-----------------------------------------------------------------------------------------------------------------------
6-1
FEATURES AND SPECIFICATIONS FEATURES
-------------------------------------------------------------------------------
6-1
SERVICE INFORMATION
----------------------------------------------------------------------------------------------------------------------
7-1
PRECAUTIONS AND REPAIR SERVICE TIPS
-----------------------------------------------------------------------------------
7-1
MICROWAVE LEAKAGE TEST
-------------------------------------------------------------------------------------------------------
7-2
POWER OUTPUT MEASUREMENT
------------------------------------------------------------------------------------------------
7-3
DISASSEMBLY INSTRUCTIONS
-----------------------------------------------------------------------------------------------------
7-4
INTERLOCK SYSTEM
------------------------------------------------------------------------------------------------------------------
7-12
INTERLOCK CONTINUITY TEST
---------------------------------------------------------------------------------------------------
7-14
TEST AND CHECKOUT PROCEDURES AND TROUBLE SHOOTING
-------------------------------------------------
7-15
A. TEST PROCEDURES
--------------------------------------------------------------------------------------------------------
7-15
B. CHECKOUT PROCEDURES
----------------------------------------------------------------------------------------------
7-18
C. TROUBLE SHOOTING
------------------------------------------------------------------------------------------------------
7-21
EXPLODED VIEW
--------------------------------------------------------------------------------------------------------------------------------
8-1
REPLACEMENT PARTS LIST
----------------------------------------------------------------------------------------------------------------
9-1
Page 4
1-1
Rated Power Consumption
----------------------------------
1,500W maximum (Microwave oven+Cook top lamps+Ventilation fan)
Frequency
---------------------------------------------------------
2,450 MHz ± 50 MHz
Power Supply
---------------------------------------------------
120 VAC, 60 Hz
Rated Current
---------------------------------------------------
13 Amp. (Microwave oven+Cook top lamp+Ventilation fan)
Magnetron Cooling
--------------------------------------------
Forced Air Cooling
Rectification
------------------------------------------------------
Rectification Voltage Double Half-Wave
Door Sealing
-----------------------------------------------------
Choke System
Safety Devices
--------------------------------------------------
Oven Cavity Thermostat:
Open at 90°C ± 5°C Fuse(20A) Primary Interlock Switch Secondary Interlock Switch Interlock Monitor
Magnetron
--------------------------------------------------------
2M214-161GP
High Voltage Capacitor
--------------------------------------
Capacitor: 1.0µF, 2.1 KV AC
High Voltage Diode
-------------------------------------------
Diode; 350mA, 9.0 KV
Cook top Lamp
-------------------------------------------------
125 V, 30 W
Cavity Lamp
-----------------------------------------------------
125 V, 30 W
Timer
---------------------------------------------------------------
Digital, up to 99 mim. 99 sec. (in each cooking stage)
Tray
-----------------------------------------------------------------
Tempered Safety Glass
Overall Dimensions
-------------------------------------------
2915/16"(W)x167/16"(H)x153/8"(D)
Oven Cavity Size
----------------------------------------------
21
9
/16"(W)x83/4"(D)x14 1/8"(H)
Effective Capacity of Oven Cavity
-----------------------
1.6 Cu.ft.
Accessories
------------------------------------------------------
Owner’s Manual & Cooking Guide, Installation Manual, Exhaust Adapter, Exhaust Damper, Mounting Kit and Two Filters, Rotating Ring Assembly.
SPECIFICATIONS
Page 5
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
Page 6
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
Page 7
4-1
OPERATING INSTRUCTIONS
32
1
4
8
19
18
24
11
13
7
12
14
5
10
22
6
9
21
15
23
17
20
16
25
CONTROL PANEL
NOTE: Styling and features vary by model.
Page 8
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
ovens 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.
Page 9
5-1
OVERALL CIRCUIT DIAGRAM
SCHEMATIC DIAGRAM
Page 10
5-2
MATRIX CIRCUIT FOR TOUCH KEY BOARD
COOK
COOK
12
13
LEVEL
POWER
N.C
STOP/
CLEAR
POPCORN
11
CUSTOM
SET
10
9
FAN
HI/LOW/OFF
COOK
WARM
HOLD
REHEAT
N.C
LIGHT
8
1
2
TIME
3
CUSTOM
1
2
TIMER
START
8
9
0
AUTO
DEFROST
TIMER
KITCHEN
N.C
CLOCK
VEGETABLE N.C
MORE LESS
POTATO
PIZZA
4
N.C
5
LIGHT
3
4
6
N.C
EZ-ON
7
5
6 7
N.C
HI/LOW/OFF
N.C N.C
TURNTABLE
ON/OFF
Page 11
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
Page 12
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
Page 13
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
Page 14
7-3
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.
MEASUREMENT WITH A FULLY 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 5 mW/cm2. Leakage for a fully assembled oven (Before the latch switch (primary) is interrupted) with the door in a slightly opened position - less than 2 mW/cm2.
NOTE WHEN MEASURING
(1) Do not exceed meter full scale deflection. (2) The test probe must be removed no faster than 1
inch/sec (2.5cm/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 operators 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.
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.
(1) Microwave power output measurement is made
with the microwave oven supplied at its rated voltage and operated at its maximum microwave power setting with a load of (1000±5) g of potable water.
(2) The water is contained in a cylindrical borosilicate
glass vessel having a maximum material thickness of 1/8" (3 mm) and an outside diameter of approximately 7.6" (190mm).
(3) The oven and the empty vessel are at ambient
temperature prior to the start of the test.
(4) The initial temperature (T1) of the water is
(10±2)°C (50°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 turntable which is in the lowest position and the microwave power switched on.
(5) The time T for the temperature of the water to rise
by a value T of (10±2)°K is measured, where T is the time in seconds and T is the temperature rise. The initial and final water temperatures are selected so that the maximum difference between the final water temperature and the ambient temperature is 5°K.
(6) The microwave power output P in watts is
calculated from the following formula :
4187 x (∆T)
T
is measured while the microwave generator is operating at full power. Magnetron filament heat­up time is not included. (about 3 sec)
(7) The water is stirred to equalize temperature
throughout the vessel, prior to measuring the final water temperature.
(8) Stirring devices and measuring instruments are
selected in order to minimize addition or removal of heat.
POWER OUTPUT MEASUREMENT
P =
WATER LOAD
TURNTABLE
Page 15
7-4
IMPORTANT NOTES:
UNIT MUST BE DISCONNECTED FROM ELEC-TRICAL OUTLET WHEN MAKING REPAIRS, RE-PLACEMENTS, 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 CONNE-CTIONS AND LEAD COLORS ARE CORRECTLY MATCHED ACCORDING TO THE OVERALL CIR-CUIT DIAGRAM. (ESPECIALLY SWITCHES AND HIGH VOLTAGE CIRCUIT.)
A. REMOVING POWER AND CONTROL
CIRCUIT BOARD (Figures 1, 2 and 3)
(1) Remove a screw securing the control panel
assembly to the oven cavity. (2) Remove the control panel with pushing it upward. (3) Remove the three connectors (CN1, CN2, CN3)
and wire leads (Relay7) from the circuit board.
(4) Remove 3 screws securing the circuit board.
(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.
DISASSEMBLY INSTRUCTIONS
Power Transformer
(CN5)-For the sensor model only
Relay 2
(CN1)
Control Panel
(Relay 7)-White
(CN5)-For the sensor model only
Relay 2
(CN1)
Circuit Board
Circuit Board
FPC Connector(S1)
Relay 7
Control Bracket
Circuit Board
Control Bracket
FPC Connector(S1)
Relay 7
Circuit Board
Figure 1
Figure 2
Figure 3
Page 16
7-5
HOW TO REMOVE THE F.P.C. CONNECTOR
Follow the steps below as illustrated in Figures 4 and 5 to remove the F.P.C. connector.
(1) Hold the edges of the plastic fastener with
thumb and forefinger. (Figure 4)
(2) Lift up the lever of the plastic fastener from the
terminal socket by lightly pressing the lever end with forefinger. (Figure 5)
(3) Remove the F.P.C. connector from the
terminal socket.
HOW TO INSERT THE F.P.C. CONNECTOR
Follow the steps below as illustrated in Figures 6 and 7 to insert the F.P.C. connector.
(1) Insert the F.P.C. connector into the terminal
socket securely with the fingers.
(2) Hold the plastic fastener with thumb and
forefinger of the other hand, and push it slowly into the terminal socket. (Figure 6) NOTE: When reconnecting the F.P.C
connector make sure that the holes on the F.P.C. connector are properly engaged with the hooks on the plastic fastener
(3) Lock the level of the plastic fastener into the
hook of the terminal socket securely by releasing the fingers. (Figure 7)
Figure 4
Figure 5
Figure 6
Figure 7
Plastic fastener
Plastic fastener
Hook
Holes
F.P.C. Connector
Plastic fastener
Holes
Terminal socket
F.P.C. Connector
Hook
Terminal socket
F.P.C. Connector
Terminal socket
Plastic fastener
F.P.C. Connector
Terminal socket
Page 17
7-6
B. REMOVING THE OUT CASE(Figure 8)
(1) Remove the vent grille by removing two screws
securing it to the out case. (2) Remove two screws securing it to the front bracket. (3) Remove two screws securing it to the air duct. (4) Remove the mounting plate by turning the two
screws securing it to the out case. (5) Remove the base plate by removing six screws
securing it to the out case. Remove the Mount, All
from the out case by removing two screws securing
it to the out case and one screw securing it to the
ventilation motor ASS'Y and cavity.
(6) Remove the power cord cover from outcase by
removing a screw.
(7) Remove the power cord to the inner of the out case
with turning power cord and remove the out case with pushing it back.
Door
Mount,All
Vent Grille
Out Case
Mounting Plate
Power cord cover
Controller
Figure 8
Page 18
7-7
C. REMOVING THE DOOR INTERLOCK
SWITCHES (Figures 9,10)
(1) Disconnect the wire leads from the interlock
switches. (2) Remove two screws securing the Latch Board. (3) Make necessary replacements and check
microwave energy leakage according to
ADJUSTMENT PROCEDURE on page 7-12.
Latch Board
Secondary Interlock Switch
Interlock Monitor Switch
Primary Interlock Switch
WIRE COLOR
SYMBOL COLOR
WH BK BR RD
BL PK GY
N.P.
WHITE BLACK BROWN RED
YL
YELLOW BLUE PINK GREY
GN
GREEN
Not Provided
Latch Board
WH
(from H.V.Transformer) WH(from Monitor S/W) WH
(
from Oven Thermostat
)
PK(from Cooktop lamp
Secondary Interlock Switch
Monitor Interlock Switch
Primary Interlock Switch
YL(from P.C.B) GN(from P.C.B)
WH
(from Secondary switch)
YL
(Turntable motor)
YL
(from Ry 2)
Figure 9
Figure 10
Page 19
7-8
D. REMOVING MAGNETRON
(Figures 11 Through 13)
(1) Remove vertgrille. (2) Remove mount, all. (3) Remove outcase. (4) Discinnect the wireleads. (5) Remove the Magnetron very carefully.
NOTES:
When removing the magnetron, make sure that its dome does not hit any adjacent parts, or it may be damaged.
When replacing the magnetron, be sure to install the magnetron gasket in the correct position and be sure that the gasket is in good condition.
After replacing the magnetron, check for microwave energy leakage with a survey meter Check microwave energy leakage must be below the limit of 5 mW/cm2. (All service adjustments should be made for minimum microwave energy leakage readings.)
vertgrille
mount all
outcase
Magnetron
Figure 11
Figure 12
Figure 13
Page 20
7-9
E. REMOVING STIRRER FAN DISK
(Figures 14-a and 14-b)
(1) Remove 1 rivet ASSY securing it to the oven upper
plate by using knife blade. (2) Rotate slightly and pull out the stirrer fan cover. (3) Remove the stirrer fan disk.
F. REMOVING DOOR (Figure 15-a)
(1) Remove the vent grille by removing two screws
securing it to the front bracket.
(2) Lift up and push the door.
NOTES:
After replacing the door, be sure to check that the primary interlock switch, the secondary interlock switch and the interlock monitor switch operate normally.
After replacing the door, check for microwave energy leakage with a survey meter. Microwave energy leakage must be below the limit of 5mW/cm2. (With a 275 ml water load)
G. DISASSEMBLING DOOR (Figure 15-b)
(1) Remove the dielectric choke by using knife blade
or small screw driver, etc.
(2) Remove two screws securing it to the door handle.
CAUTION: Be careful not to damage door seal
plate with the screwdriver.
Door Screen
Figure 14-b
Figure 15-a
Figure 15-b
Figure 14-a
Page 21
7-10
H. ASSEMBLING DOOR
(1) When mounting the door assembly to the oven
assembly, be sure to adjust the door assembly parallel to the chassis. Also adjust so the door has no play between the inner door surface and oven frame assembly. If the door assembly is not mounted properly, microwaves may leak from the clearance between the door and the oven.
I. REMOVING THE VENTILATION FAN ASS'Y
(1) Remove the mounting plate by removing two
screws securing it to the back plate. (See Figure 16)
(2) Remove the two screws securing the MOUNT, ALL
and one screw securing the ventilation fan ASS'Y. (See Figure 17)
(3) Carefully pull the ventilation motor ASS'Y out of the
microwave oven. (See Figure 18)
J. REPLACING THE HUMIDITY SENSOR
(For sensor model only)
(1) Remove the sensor by removing two screws
securing it to the air duct. (See Figure 18-a)
(2) Mount the new humidity sensor to the air duct.
Space
MOUNT, ALL
Figure 16
Figure 17
Figure 18
Figure 18-a
Page 22
7-11
K. REMOVING THE TURNTABLE MOTOR
(1) Remove the turntable. (2) Remove the turntable shaft VERY CAREFULLY
with a slotted screwdriver. (Figure 19)
(3) Remove the base plate by removing 6 screws
securing it to the oven cavity. (Figure 20)
(4) Disconnect the leadwire from the turntable motor
terminals.
(5) Remove the 1 or 2 screws securing the turntable
motor to the oven cavity ASS'Y. (Figure 21)
NOTES:
Remove the leadwire from the turntable motor VERY CAREFULLY.
Be sure to grasp the connector not the wires when removing.
Wire Leads
Turntable Motor
Figure 19
Figure 20
Figure 21
Page 23
7-12
ADJUSTMENT PROCEDURES
To avoid possible exposure to microwave energy leakage, adjust the door latches and interlock switches, using the following procedure.
The Interlock Monitor and Primary Interlock Switch act as the final safety switch protecting the user from microwave energy. The terminals between COM and NC of the Interlock Monitor must close when the door is opened. After adjusting the Interlock Monitor Switch, make sure that it is correctly connected. Mounting of the primary/monitor/secondary switches to the latch board.
CHECK THE DOOR LATCH AND SWITCH CLOSING.
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 22-a.
(2) Close the door tightly and check gaps A and B to
be sure they are no more than 1/64 (0.5 mm). See Figure 22-b for close-up view of gaps A and B (door latches). If all gaps are less than 1/64 (0.5 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” (0.5 mm), you will need to adjust the latch board”. Go to step 3 and follow all steps in order.
ADJUST THE LATCH AND SWITCH CLOSING
(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” (0.5 mm). Hold the latch board tightly in this position until you check the sequence of the switches in steps 5 and 6.
INTERLOCK SYSTEM
INTERLOCK SYSTEM INTERLOCK MECHANISM
The door lock mechanism is a device which has been specially designed to eliminate completely microwave activity when the door is opened during cooking and thus to prevent the danger resulting from the microwave leakage.
LATCH
LATCH BOARD
0-1/64"
0-1/64"
Latch Board
Secondary Interlock Switch
Interlock Monitor Switch
Primary Interlock Switch
Figure 22-a
Figure 22-b
Page 24
7-13
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
switches in Steps 5 and 6, tighten the latch board screws at that point.
TEST THE MICROWAVE ENERGY LEAKAGE
Make sure the microwave energy leakage is below the limit of 1mW/cm2(with a 275 ml water load) and 5mW/cm2(with a 275 ml water load without the cabinet) when measured with a survey meter.
Page 25
7-14
A. PRIMARY INTERLOCK SWITCH TEST
When the door is opened slowly, an audible click should be heard at the same time or successively at intervals and the latches should activate the switches with an audible click. If the latches do not activate the switches when the door is closed, the switches should be a adjusted in accordance with the adjustment procedure. Disconnect the wire lead from the primary switch. Connect the ohmmeter leads to the common (COM) and normally open (NO) terminal of the switch. The meter should indicate an open circuit in the door open condition. When the door is closed, the meter should indicate a closed circuit. When the primary switch operation is abnormal, make the necessary adjustment or replace the switch only with the same type of switch.
B. SECONDARY INTERLOCK SWITCH TEST
Disconnect the wire lead from the secondary switch. Connect the ohmmeter leads to the common (COM) and normally open (NO) terminals of the switch. The meter should indicate a open circuit in the door open condition. When the door is closed, meter should indicate an closed circuit. When the secondary switch operation is abnormal, make the necessary adjustment or replace the switch only with the same type of switch.
C. MONITOR SWITCH TEST
Disconnect the wire lead from the monitor switch. Connect the ohmmeter leads to the common (COM) and normally closed (NC) terminals of the switch. The meter should indicate closed circuit in the door open condition. When the door is closed, meter should indicate an open circuit. When the monitor switch operation is abnormal, replace with the same type of switch.
NOTE: After repairing the door or the interlock system, it is necessary to do this continuity test before operating the oven.
INTERLOCK CONTINUITY TEST
COMPONENTS TEST PROCEDURE RESULTS
SWITCHES Check for continuity of the Door Door (Wire leads removed) switch with an Ohm-meter open closed
Primary Switch
Monitor Switch
Secondary Switch
NOTE: After checking for the continuity of switches, make sure that they are
connected correctly.
WARNING : FOR CONTINUED PROTECTION AGAINST EXCESSIVE RADIATION
EMISSION, REPLACE ONLY WITH IDENTICAL REPLACEMENT PARTS.
TYPE NO. SZM-V16-FA-63 OR VP-533A-OF OR V-5230Q FOR PRIMARY SWITCH TYPE NO. SZM-V16-FA-62 OR VP-532A-OF OR V-5220Q FOR MONITOR SWITCH TYPE NO. SZM-V16-FA-63 OR SZM-V01-FA-33 OR VP-533A-OF OR VP-133A-OD OR V-5230Q FOR
SECONDARY SWITCH
COM
COM
NO
NC
COM
NO
Page 26
7-15
TEST AND CHECKOUT PROCEDURES, AND TROUBLE SHOOTING
A. TEST PROCEDURES
- CAUTIONS -
- DISCONNECT THE POWER SUPPLY CORD FROM THE WALL OUTLET WHENEVER REMOVINGING THE CABINET FROM THE UNIT. PROCEED WITH THE TESTS ONLY AFTER DISCHARGING THE HIGH VOLTAGE CAPACITOR AND REMOVING THE WIRE LEADS FROM THE PRIMARY WINDING OF THE HIGH VOLTAGE TRANSFORMER. (SEE FIGURE 23)
- ALL OPERATIONAL CHECKS WITH MICROWAVE ENERGY MUST BE DONE WITH A LOAD (1 LITER OF WATER IN CONTAINER) IN THE OVEN.
COMPONENTS TEST PROCEDURES RESULTS
NOTE: A MICROWAVE ENERGY LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS
SERVICED FOR ANY REASON.
MAGNETRON
(Wire leads are
removed)
HIGH-VOLTAGE
TRANSFORMER
(Wire leads are
removed)
1) Measure the resistance: Across the filament terminals of the magnetron with an ohm-meter on Rx1 scale.
2) Measure the resistance: Between each filament terminal of the magnetron and the chassis ground with an ohm-meter on high test scale.
1) Measure the resistance: With an ohm-meter on Rx1 scale. a. Primary winding; b. Filament winding; c. Secondary winding;
2) Measure the resistance: With an ohm-meter on highest scale. a. Primary winding to ground; b. Filament winding to ground;
Normal reading:
Less than 1 ohm.
Normal reading:
Infinite ohms.
NOTE: Replace the magnetron, if the magnetron checks and all of the high voltage component tests are good, but the unit still does not heat a load.
Normal readings:
Approx. 0.3 to 0.5 ohm. Less than 0.1 ohm. Approx. 65 to 120 ohms.
Normal readings:
Infinite ohms. Infinite ohms.
Figure 23
Secondary Winding
Primary Winding
Filament Winding
Page 27
7-16
COMPONENTS TEST PROCEDURES RESULTS
HIGH-VOLTAGE
CAPACITOR
HIGH-VOLTAGE
DIODE
Measure the resistance: (1) Terminal to terminal
(2) Terminal to case
Measure the continuity: (1) Forward
(1) Reverse
Normal reading:
Momentarily indicates several ohms, and then gradually returns to infinite ohms.
Abnormal reading:
Indicates continuity or infinite ohms from the beginning.
Normal readings:
Infinite.
Abnormal reading:
Indicates continuity.
Normal readings:
continuity.
Abnormal reading:
Infinite.
Normal readings:
Infinite.
Abnormal reading:
continuity.
Ohm­meter
Ohm­meter
Ohm­meter
Ohm­meter
Figure 24-a
Figure 24-b
Figure 25-a
Figure 25-b
Page 28
7-17
COMPONENTS TEST PROCEDURES RESULTS
TOUCH KEY
BOARD
Measure the resistance between terminal pins of connector KEY CONNECTOR.
NOTE:
When reconnecting the FPC connector, make sure that the holes on the FPC connector are properly engaged with hooks on the plastic fastener.
MATRIX CIRCUIT FOR
TOUCH KEY BOARD
CONNECTOR(KEY CON) (For detail matrix circuit of each model, refer to page 5-2.)
FPC CONNECTOR
Top
Resistance
value
When
touched
Less than
400 ohms
When not
touched
More than
1 mega ohm
Figure 26
COOK
COOK
12
13
LEVEL
POWER
N.C
STOP/
CLEAR
POPCORN
11
CUSTOM
SET
10
9
FAN
HI/LOW/OFF
COOK
WARM
HOLD
REHEAT
N.C
LIGHT
8
1
2
TIME3CUSTOM
1
2
TIMER
START
8
9
0
AUTO
DEFROST
TIMER
KITCHEN
N.C
CLOCK
VEGETABLE N.C
MORE LESS
PO TATO
PIZZA
4
N.C
5
LIGHT
3
4
6
N.C
EZ-ON
7
5
6 7
N.C
HI/LOW/OFF
N.C N.C
TURNTABLE
ON/OFF
1 2 3 4 5 6 7 8 9 10 11 12 13
Figure 27
Page 29
7-18
COMPONENTS TEST PROCEDURES RESULTS
RELAY2
Check for continuity of relay 7 with an ohm-meter. (Remove wire leads from relay 7 and operate the unit.)
POWER
LEVEL
1
2
3
4
5
6
7
8
9
10
4 sec
6 sec
8 sec
10 sec
12 sec
14 sec
16 sec
18 sec
20 sec
22 sec
18 sec
16 sec
14 sec
12 sec
10 sec
8 sec
6 sec
4 sec
2 sec
0
Figure 28
Relay 2
NOTES:
A MICROWAVE ENERGY TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS SERVICED FOR
MAKE SURE THE WIRE LEADS ARE IN THE CORRECT POSITION.
WHEN REMOVING THE WIRE LEADS FROM THE PARTS, BE SURE TO GRASP THE CONNECTOR, NOT
THE WIRES.
B. CHECKOUT PROCEDURES
(1) CHECKOUT PROCEDURES FOR FUSE BLOWING
CAUTION: REPLACE BLOWN FUSE WITH 20 AMPERE FUSE.
NOTES:
If the fuse is blown by an improper switch operation, replace all switches and the fuse at the same time. After replacing the defective switches with new ones, make sure that they are correctly connected.
Check for microwave energy leakage according to INTERLOCK ADJUSTMENT PROCEDURES on page 7-12 when the primary interlock, secondary interlock switches and/or the interlock monitor switches are adjusted or replaced.
PROBLEMS CAUSES
Fuse blows immediately after the door is closed.
Fuse blows immediately after the door is opened.
Fuse blows when the door is closed and START key is touched.
Improper operation of the primary interlock, secondary interlock switches and/or the interlock monitor switch.
Malfunction of the high voltage transformer; the high voltage capacitor including the diode, the magnetron, the blower motor or the circuit board.
Page 30
7-19
(2) CHECKOUT PROCEDURES FOR RELAY.
- PROBLEM (A) -
Vent fan motor and oven lamp turn on without touching
START key when the door is closed.
Remove the mate connector of I/O CON from the circuit board. Does the unit still operate?
Replace the circuit board
Replace RELAY1, 12
NO
NO
YES
YES
GOOD
Defective RELAY1, 12
- PROBLEM (B) -
Vent fan motor and oven lamp turn on When the door
is closed and START key is touched.
Measure the voltage at pin NO. 47, 50 of U01 or 48, 49, 51 of U01 Voltage reading: 0 Vdc
Replace the circuit board
Defective
RELAY1, 12 or poor
connection of
RELAY1, 12
Replace
RELAY1, 12 or correct
the connection.
YES
NO
NO
YES
GOOD
Page 31
7-20
(3) CHECKOUT PROCEDURES FOR CIRCUIT
BOARD The following symptoms indicate a defective circuit board.
1) The start function fails to operate but the high voltage Systems, the interlock switches, the door sensing and the relay check good.
2) The unit with a normal relay continuously operates.
3) Proper temperature measurement is not obtained.
4) The buzzer does not sound or continues to sound.
5) Some segments of one or more digits do not light up, or they continue to light up, or segments light when they should not.
6) Wrong figures appear.
7) The figures of all digits.
8) Some of the indicators do no flicker light up.
9) The clock does not keep time properly.
NOTE: A MICROWAVE ENERGY LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS
SERVICED FOR ANY REASON.
Page 32
7-21
C. TROUBLE SHOOTING
Before following this troubleshooting read TRIAL OPERATION on page 6- 1.
• “DISPLAY Problems, “A” thru “C
• “HELP UP” Problems, “D” thru “E” • “BUZZER Problems, “F”
PROBLEM - A: PLEASE SET TIME OF DAY does not appear in display window when power supply cord is
plugged into wall outlet.
PROBLEM - B: Display does not show correct numbers and/ or
correct indications when programmed.
Check: 1. POWER SUPPLY
2. FUSE (See CHECKOUT PROCEDURES FOR FUSE BLOWING: on page 7- 18)
3. OVEN CAVITY THERMOSTAT
1
1
Measure voltage between pin 1
and pin 3 of connector CN1.
0
120
120V
Replace
circuit board
Normal
circuit board
Normal
resistance
Voltage
incorrect
Correct
connections
0
120
WH
RD
Runs
Runs
Measure resistance of touch
key board after removing
connector S1.
(See page 7-4 and 7-17)
Normal
resistance
Resistance
incorrect
Replace touch
key board.
Normal touch
key board
Poor
contact
Correct
seating
Contact
ok
Replace
circuit board
Normal
circuit board
Normal
contact
Check contact
of connector S1
Runs
Runs
Runs
Page 33
7-22
PROBLEM - E: Unit does not heat up even if display counts down when
START key is touched for HIGH POWER cooking.
Check: 1. PRIMARY AND SECONDARY INTERLOCK SWITCHES
2. THERMOSTAT
1
2
Runs
Contact
OK
NO
continuity
Replace
circuit board
Normal
circuit board
Poor contact
Replace
circuit board
Normal
circuit board
Contact OK
Normal
contact
Correct
seating
Check contact of
connector S1
Check the contact of
relay 7(see page 7-18)
Runs
Runs
Resistance
incorrect
Check the continuity of
H.V.C. (see page 7-16)
Normal H.V.T.
Resistance
incorrect
Normal H.V.C.
Abnormal
Replace H.V.D.
Normal
Magnetron
Replace
Magnetron
Normal
Normal
H.V.D.
Check the
continuity of H.V.D.
(see page 7-16)
Replace H.V.C.
Normal
resistance
Replace H.V.T.
Normal
resistance
Measure resistance of
H.V.Transformer
(see page 7-15)
Runs
Runs
Runs
Runs
Page 34
7-23
PROBLEM - F: No buzzing when touching the key, between
stages or at end of cooking
1
Normal
circuit board
Check normal
operation
circuit board
Replace
circuit board
Runs
Page 35
7-24
PROBLEM - Ventilation fan does not operate when FAN HIGH/ LOW key is touched.
1
Contact
OK
NO
contact
Replace
magnetron thermal fuse
and oven thermostat
Poor contact
Replace
circuit board
Normal
circuit board
Contact OK
Normal
contact
Correct
seating
Check contact
of connector S1
(see page 7-4)
Replace
ventilation
motor ASS Y
NO runs
Normal
ventilation
motor ASS Y
Check the contact of
magnetron thermal
fuse and oven thermostat
Runs
Runs
Runs
Runs
Check: 1. POWER SUPPLY
2. FUSE
Page 36
8-1
DOOR PARTS
EXPLODED VIEW
13581A
13551A
13213A
13536A
13552A
WTT021
14026A
14970A
13650A
Page 37
8-2
CONTROLLER PARTS
268711
24810P
23551A
24781M
WTP018
Page 38
8-3
OVEN CAVITY PARTS
WTT027
WTT028
33112U
34960A
34810Q
*01
368771
56804A
63303A
63302A
34890C
34810T
WTT022
35230A
36912C
WTT022
33052A
35026G
34930R
*04
33530A
33550L
Page 39
8-4
LATCH BOARD PARTS
43501A
WSZ084
43500A
466001
466003
466001
44510A
Page 40
8-5
INTERIOR PARTS (I)
WSZ002
56324A
WTT021
56170D
53300B
WSZ002
53300A
50CZZH
54810C
56851D
WSZ002
WTP013
36549S
35889A
34370T
33390G
WTT021
33740A
Page 41
8-6
INTERIOR PARTS (II)
WTP004
36549V
56912B
53550L
55231C
56804A
WTT028
55262A
56411A
50FZZA
56930V
55006F
568771
WSZ002
54974T
56501A
55892A
53550F
340511
54930F
53740A
WTT021
Page 42
8-7
INSTALLATION PARTS
VINYL
BAG
63861A
65862B
65862D
63300M
Page 43
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