Sharp R-312AW, R-312AK User Manual

SER VICE MANU AL
S5707R312APK/
MICROWAVE OVEN
R-312AW R-312AK
CHECK
INSTANT ACTION
To adjust quantity-touch pad again
POPCORN
BEVERAGE
DINNER
REHEAT
PLATE
CASSEROLE
BAKED
FRESH
POTATO
VEGETABLE
FRESH
FROZEN
ROLL / MUFFIN
ROLL / MUFFIN
1
Ground meat
2
Steaks / chops
COMPU
3
Chicken pieces
DEFROST
POWER
TIMER
LEVEL
CLOCK
STOP
START
CLEAR
MINUTE PLUS
R-312AW
In the interest of user-safety the oven should be restored to its original condition and only parts identical to those specified should be used.
TABLE OF CONTENTS
PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICE TO
AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY ...................INSIDE FRONT COVER
FOREWORD.......................................................................................................................................................... 3
OPERATION..........................................................................................................................................................6
TEST PROCEDURE ............................................................................................................................................10
TOUCH CONTROL PANEL .................................................................................................................................15
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ................................................................19
PICTORIAL DIAGRAM ........................................................................................................................................25
POWER UNIT CIRCUIT ......................................................................................................................................26
CONTROL PANEL CIRCUIT ...............................................................................................................................27
PRINTED WIRING BOARD .................................................................................................................................28
PARTS LIST ........................................................................................................................................................29
PACKING AND ACCESSORIES .........................................................................................................................33
R-312AW R-312AK
Page
ON
MODELS
DEF. LBS. QTY.
SHARP ELECTRONICS CORPORATION
Service Headquarters: Sharp Plaza, Mahwah, New Jersey 07430-2135
R-312AW R-312AK
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.
BEFORE SERVICING
Before servicing an operative unit, perform a microwave emission check as per the Microwave Measurement Procedure outlined in this service manual. If microwave emissions level is in excess of the specified limit, contact SHARP ELECTRONICS CORPORATION immediately @1-800-237-4277.
If the unit operates with the door open, service person should 1) tell the user not to operate the oven and 2) contact SHARP ELECTRONICS CORPORATION and Food and Drug Administration's Center for Devices and Radiological Health immediately.
Service personnel should inform SHARP ELECTRONICS CORPORATION of any certified unit found with emissions in excess of 4mW/cm2. The owner of the unit should be instructed not to use the unit until the oven has been brought into compliance.
R-312AW R-312AK
1
R-312AW R-312AK
MICROWAVE MEASUREMENT PROCEDURE
A. Requirements:
1) Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven should not exceed 1mW/cm2 at any point 5cm or more from the external surface of the oven, measured prior to acquisition by a purchaser, and thereafter (through the useful life of the oven), 5 mW/cm2 at any point 5cm or more from the external surface of the oven.
2) Safety interlock switches Primary interlock relay and door sensing switch shall prevent microwave radiation emission in excess of the requirement as above mentioned, secondary interlock switch shall prevent microwave radiation emission in excess of 5 mW/cm2 at any point 5cm or more from the external surface of the oven.
B. Preparation for testing: Before beginning the actual measurement of leakage, proceed as follows:
1) Make sure that the actual instrument is operating normally as specified in its instruction booklet. Important:
Survey instruments that comply with the requirement for instrumentation as prescribed by the performance standard for microwave ovens, 21 CFR 1030.10(c)(3)(i), must be used for testing.
2) Place the oven tray in the oven cavity.
3) Place the load of 275±15 ml (9.8 oz) of tap water initially at 20±5˚C (68˚F) in the center of the oven cavity.
The water container shall be a low form of 600 ml (20 oz) beaker with an inside diameter of approx. 8.5 cm (3-1/2 in.) and made of an electrically nonconductive material such as glass or plastic. The placing of this standard load in the oven is important not only to protect the oven, but also to insure that any leakage is measured accurately.
4) Set the cooking control on Full Power Cooking Mode
5) Close the door and select a cook cycle of several minutes. If the water begins to boil before the survey is completed,
replace it with 275 ml of cool water.
C. Leakage test:
Closed-door leakage test (microwave measurement)
1) Grasp the probe of the survey instrument and hold it perpendicular to the gap between the door and the body of the oven.
2) Move the probe slowly, not faster than 1 in./sec. (2.5 cm/sec.) along the gap, watching for the maximum indication on the meter.
3) Check for leakage at the door screen, sheet metal seams and other accessible positions where the continuity of the metal has been breached (eg., around the switches, indicator, and vents). While testing for leakage around the door pull the door away from the front of the oven as far as is permitted by the closed latch assembly.
4) Measure carefully at the point of highest leakage and make sure that the highest leakage is no greater than 4mW/cm2, and that the secondary interlock switch does turn the oven OFF before any door movement.
NOTE: After servicing, record data on service invoice and microwave leakage report.
2
SERVICE MANUAL
MICROWAVE OVEN
PRODUCT DESCRIPTION
R-312AW R-312AK
R-312AW / R-312AK
FOREWORD
This Manual has been prepared to provide Sharp Electronics Corp. Service Personnel with Operation and Service Informa­tion for the SHARP MICROWAVE OVENS, R-312AW, R­312AK.
It is recommended that service personnel carefully study the entire text of this manual so that they will be qualified to render satisfactory customer service.
Check the interlock switches and the door seal carefully. Special attention should be given to avoid electrical shock and microwave radiation hazard.
GENERAL INFORMATION
OPERATION
TROUBLESHOOTING GUIDE AND TEST PROCEDURE
TOUCH CONTROL PANEL
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
WIRING DIAGRAM
SHARP ELECTRONICS CORPORATION
SHARP PLAZA, MAHWAH,
NEW JERSEY 07430-2135
PARTS LIST
3
R-312AW R-312AK
SPECIFICATION
ITEM DESCRIPTION
Power Requirements 120 Volts / 13.0 Amperes
60 Hertz Single phase, 3 wire grounded
Power Output 1000 watts (IEC-705 TEST PROCEDURE)
Operating frequency of 2450MHz
Case Dimensions Width 20-1/2"
Height 11-7/8" Depth 15-7/8"
Cooking Cavity Dimensions Width 13-3/4"
Height 8-3/8"
0.9 Cubic Feet Depth 14-7/8" Control Complement Touch Control System
Clock ( 1:00 - 12:59 ) Timer (0 - 99 min. 99 seconds)
Microwave Power for Variable Cooking Repetition Rate;
P-HI..................................................Full power throughout the cooking time
P-90 ....................................................................approx. 90% of Full Power
P-80 ....................................................................approx. 80% of Full Power
P-70 ....................................................................approx. 70% of Full Power
P-60 ....................................................................approx. 60% of Full Power
P-50 ....................................................................approx. 50% of Full Power
P-40 .....................................................................approx. 40% of Full Power
P-30 .....................................................................approx. 30% of Full Power
P-20 ....................................................................approx. 20% of Full Power
P-10 .....................................................................approx. 10% of Full Power
P-0 .................................................... No power throughout the cooking time
INSTANT ACTION pads COMPU DEFROST pad Number selection pads POWER LEVEL pad TIMER/CLOCK pad STOP/CLEAR pad START/MINUTE PLUS pad
Oven Cavity Light Yes Safety Standard UL and C-UL Listed FCC Authorized
DHHS Rules, CFR, Title 21, Chapter 1, Subchapter J Department of National Health and Welfare CANADA.
GENERAL INFORMATION
GROUNDING INSTRUCTIONS
This oven is equipped with a three prong grounding plug. It must be plugged into a wall receptacle that is properly installed and grounded in accordance with the National Electrical Code and local codes and ordinances. In the event of an electrical short circuit, grounding reduces the risk of electric shock by providing an escape wire for the electric current.
WARNING: Improper use of the grounding plug can result in a risk of electric shock.
4
R-312AW R-312AK
Electrical Requirements The electrical requirements are a 115 -120 volt 60 Hz, AC only, 15 or 20 amp. fused electrical supply. It is recommended that a separate
3-Pronged Plug
Grounded Receptacle Box
circuit serving only this appliance be provided. When installing this appliance, observe all applicable codes and ordinances. A short power-supply cord is provided to reduce risks of becoming entangled in or tripping over a longer cord. Where a two-pronged wall-receptacle is encountered, it is the personal responsibility and obligation of the customer to contact a qualified
Grounding Pin
electrician and have it replaced with a properly grounded three-pronged wall receptacle or have a grounding adapter properly grounded and polarized. If an extension cord must be used, it should be a 3-wire, 15
3-Pronged Receptacle
amp. or more cord. Do not drape over a countertop or table where it can be pulled on by children or tripped over accidentally.
CAUTION: DO NOT UNDER ANY CIRCUMSTANCES CUT OR REMOVE THE ROUND GROUNDING PRONG FROM
THIS PLUG.
1. One touch door open button. Push to open door.
2. Door latches. The oven will not operate unless the door is securely closed.
3. Removable turntable support.
4. Removable turntable. The turntable will rotate clockwise or counterclockwise.
5. Oven lamp. It will light when oven is operating.
6. Oven door with see-through window.
7. Ventilation openings. (Rear)
8. Auto-Touch control panel.
9. Time display: Digital display, 99 minutes 99 seconds.
10.Coupling.
11.Wave guide cover.
12.Power supply cord
OVEN DIAGRAM
10
11
2
TOUCH CONTROL PANEL
56
7
9
8
12
1
4
3
DEF. LBS. QTY.
ON
INSTANT ACTION
To adjust quantity-touch pad again
POPCORN
DINNER
PLATE
BAKED
POTATO
FRESH
ROLL / MUFFIN
Ground meat
1
Steaks / chops
2
Chicken pieces
3
POWER
LEVEL
STOP
CLEAR
BEVERAGE
REHEAT
CASSEROLE
FRESH
VEGETABLE
FROZEN
ROLL / MUFFIN
COMPU
DEFROST
START
MINUTE PLUS
CHECK
TIMER
CLOCK
Time display
Indicator
5
R-312AW R-312AK
OPERATION
DESCRIPTION OF OPERATING SEQUENCE
The following is a description of component functions during oven operation.
OFF CONDITION
Closing the door activates door sensing switch, primary interlock switch and the third door switch. (In this condition, the monitor switch contacts are opened.) When oven is plugged in, 120 volts A.C. is supplied to the noise filter and the control unit. (Figure O-1).
1. The display will show flashing “88:88”. To set any program or set the clock, you must first touch the STOP/CLEAR pad. The display will clear, and “ : “ will appear.
COOKING CONDITION
Program desired cooking time by touching the Number pads and program the power level by touching the POWER LEVEL pad and Number pad. When the START pad is touched, the following operations occur:
1. The contacts of relays are closed and components connected to the relays are turned on as follows.
(For details, refer to Figure O-2)
RELAY CONNECTED COMPONENTS RY-1 oven lamp/turntable motor/fan motor RY-2 power transformer
2. 120 volts A.C. is supplied to the primary winding of the power transformer and is converted to about 3.2 volts A.C. output on the filament winding, and approximately 2150 volts A.C. on the high voltage winding.
3. The filament winding voltage heats the magnetron filament and the H.V. winding voltage is sent to a voltage doubler circuit.
4. The microwave energy produced by the magnetron is channeled through the waveguide into the cavity feed­box, and then into the cavity where the food is placed to be cooked.
5. Upon completion of the cooking time, the power transformer, oven lamp, etc. are turned off, and the generation of microwave energy is stopped. The oven will revert to the OFF condition.
6. When the door is opened during a cook cycle, monitor switch, door sensing switch, primary interlock switch and third door switch are activated with the following results. The circuits to the turntable motor, the cooling fan motor, and the high voltage components are de-energized, and the digital readout displays the time still remaining in the cook cycle when the door was opened.
7. The monitor switch is electrically monitoring the operation of the primary interlock switch and it is mechanically associated with the door so that it will function in the following sequence.
(1)When the door opens from a closed position, the third
door switch, primary interlock switch and door sensing switch open their contacts, and then the monitor switch contacts close.
(2) When the door is closed from the open position, the
monitor switch contacts first open, and then the contacts of the primary interlock switch, door sensing switch and
third door switch close. If the primary interlock switch fails with their contacts closed when the door is opened, the closing of the monitor switch contacts will form a short circuit through the monitor fuse and primary interlock switch causing the monitor fuse to blow.
POWER LEVEL P-0 TO P-90 COOKING
When Variable Cooking Power is programmed, the 120 volts A.C. is supplied to the power transformer intermittently through the contacts of relay (RY-2) which is operated by the control unit within an interval second time base. Micro­wave power operation is as follows:
VARI-MODE ON TIME OFF TIME
Power 10(P-HI) 32 sec. 0 sec.
(100% power)
Power 9(P-90) 30 sec. 2 sec.
(approx. 90% power)
Power 8(P-80) 26 sec. 6 sec.
(approx. 80% power)
Power 7(P-70) 24 sec. 8 sec.
(approx. 70% power)
Power 6(P-60) 22 sec. 10 sec.
(approx. 60% power)
Power 5(P-50) 18 sec. 14 sec.
(approx. 50% power)
Power 4(P-40) 16 sec. 16 sec.
(approx. 40% power)
Power 3(P-30) 12 sec. 20 sec.
(approx. 30% power)
Power 2(P-20) 8 sec. 24 sec.
(approx. 20% power)
Power 1(P-10) 6 sec. 26 sec.
(approx. 10% power)
Power 0(P-0) 0 sec. 32 sec.
(0% power)
Note: The ON/OFF time ratio does not correspond with
the percentage of microwave power, because approx. 2 seconds are needed for heating of the magnetron filament.
6
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED
2. CLOCK APPEARS ON DISPLAY
R-312AW R-312AK
120V AC
60 Hz
OVEN
THERMAL 
CUT-OUT
HN
FUSE 20A
CAPACITOR
NOISE FILTER
NOISE SUPPRESSION COIL
0.22µF / AC 250V
LINE CROSS CAPACITOR
LINE BYPASS
0.0033µF / AC 125V
CAPACITOR
LINE BYPASS
0.0033µF / AC 125V
Figure O-1. Oven Schematic-Off Condition
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED
2. COOKING TIME PROGRAMMED
3. VARIABLE COOKING CONTROL "HIGH"
4. "START" PAD TOUCHED
MAGNETRON
THERMAL 
CUT-OUT
OVEN
LAMP
A3
PRIMARY INTERLOCK SWITCH
OL
TURNTABLE
MOTOR
CONTROL UNIT
TTM
(RY-1)
FAN 
MOTOR
THIRD DOOR SWITCH
POWER 
SWITCH
TRANSFORMER
CAPACITOR
0.94µF
MAGNETRON
RECTIFIER
FM
DOOR SENSING SWITCH
A1
B1
COM.
(RY-2)
B2
SECONDARY
INTERLOCK
RELAY
N.O.
MONITOR 
120V AC
60 Hz
HN
FUSE 20A
NOISE FILTER
NOISE SUPPRESSION COIL
CAPACITOR
LINE BYPASS
0.0033µF / AC 125V
0.22µF / AC 250V
LINE CROSS CAPACITOR
CAPACITOR
LINE BYPASS
0.0033µF / AC 125V
Figure O-2. Oven Schematic-Cooking Condition
OVEN
THERMAL 
CUT-OUT
MAGNETRON
THERMAL 
CUT-OUT
OVEN
LAMP
A3
PRIMARY INTERLOCK SWITCH
OL
TURNTABLE
MOTOR
CONTROL UNIT
7
TTM
(RY-1)
FAN 
MOTOR
THIRD DOOR SWITCH
POWER 
SWITCH
TRANSFORMER
CAPACITOR
0.94µF
MAGNETRON
RECTIFIER
FM
DOOR SENSING SWITCH
A1
B1
COM.
(RY-2)
B2
SECONDARY
INTERLOCK
RELAY
N.O.
MONITOR 
R-312AW R-312AK
DESCRIPTION AND FUNCTION OF COMPONENTS
DOOR OPEN MECHANISM
The door is opened by pushing the open button on the control panel, refer to the Figure D-1. When the open button is pushed, the open button pushes up the switch lever, and then the switch lever pushes up the the latch head. The latch heads are moved upward and re­leased from latch hook. Now the door will open.
LATCH HOOK
DOOR SENSING SWITCH
LATCH HEADS
MONITOR  SWITCH
SWITCH LEVER
THIRD DOOR  SWITCH
PRIMARY INTERLOCK  SWITCH
Figure D-1. Door Open Mechanism
DOOR SENSING, THIRD DOOR AND PRIMARY INTERLOCK SWITCHES
The primary interlock switch is mounted in the lower position of the latch hook and the door sensing switch in the secondary interlock system is mounted in the upper position of the latch hook. The third door switch is mounted in the lower position at the back of the latch hook. They are activated by the latch heads on the door. When the door is opened, the switches interrupt the circuit to all components except the oven lamp and the noise filter. A cook cycle cannot take place until the door is firmly closed thereby activating both interlock switches. The secondary interlock system consists of the door sensing switch and secondary interlock relay located on the control circuit board.
MONITOR SWITCH
The monitor switch is activated (the contacts opened) by the latch head on the door while the door is closed. The switch is intended to render the oven inoperative by means of blowning the monitor fuse when the contacts of the primary interlock switch fail to open when the door is opened.
Functions:
1. When the door is opened, the monitor switch contact close (to the ON condition) due to their being normally closed. At this time the primary interlock switch is in the OFF condition (contacts open) due to its being normally open contact switches.
2. As the door goes to a closed position, the monitor switch contacts are first opened and then the door sensing
switch, the primary interlock switch and third door switch contacts close. (On opening the door, each of these switches operate inversely.)
3. If the door is opened, and primary interlock switch contacts fail to open, the monitor fuse blows simultaneously with closing of the monitor switch contacts.
CAUTION: BEFORE REPLACING A BLOWN MONITOR
FUSE TEST THE PRIMARY INTERLOCK SWITCH AND MONITOR SWITCH FOR PROPER OPERATION. (REFER TO CHAP­TER “TEST PROCEDURE”).
NOTE: MONITOR FUSE AND SWITCH ARE REPLACED
AS AN ASSEMBLY
TURNTABLE MOTOR
The turntable motor rotates the turntable located on the bottom of the oven cavity, so that the foods on the turntable cook evenly during cooking. The turntable may turn in either direction.
COOLING FAN MOTOR
The cooling fan motor drives a blade which draws external cool air. This cool air is directed through the air vanes surrounding the magnetron and cools the magnetron. This air is channelled through the oven cavity to remove steam and vapours given off from the heating foods. It is then exhausted through the exhausting air vents at the oven cavity.
OVEN THERMAL CUT-OUT
The thermal cut-out, located on the top of the oven cavity, is designed to prevent damage to the oven by fire. If the foods load is overcooked, by either error in cook time or defect in the control unit, the thermal cut-out will open. Under normal operation, the oven thermal cut-out remains closed. However, when abnormally high temperatures are reached within the oven cavity, the oven thermal cut-out will open at 257˚F(125˚C), causing the oven to shut down.
MAGNETRON THERMAL CUT-OUT
The thermal cut-out located near the magnetron is designed to prevent damage to the magnetron if an over heated condition develops in the tube due to cooling fan failure, obstructed air guide, dirty or blocked air intake, etc. Under normal operation, the thermal cut-out remains closed. However, when abnormally high temperatures are reached within the magnetron, the thermal cut-out will open at 203˚F(95˚C) causing the oven to shut down, when the magnetron has cooled to 167˚F (75˚C), the thermal cut-out closes and cook cycle will resume.
NOISE FILTER
The noise filter prevents the redio frequency interference that might flow back in the power circuit.
8
R-312AW R-312AK
TROUBLESHOOTING GUIDE
When troubleshooting the microwave oven, it is helpful to follow the Sequence of Operation in performing the checks. Many of the possible causes of trouble will require that a specific test be performed. These tests are given a procedure letter which will be found in the "Test Procedure"section.
IMPORTANT: If the oven becomes inoperative because of a blown monitor fuse in the monitor switch and primary interlock
switch circuit, check the monitor switch and primary interlock switch before replacing the monitor fuse. If monitor fuse is replaced, the mintor switch should be replaced at the same time.
CK = Check / RE = Replace
CONDITION
OFF CONDITION
COOKING CONDITION
TEST PROCEDURE
AND
POSSIBLE CAUSE
DEFECTIVE PARTS
PROBLEM
Home fuse or circuit breaker blows when power cord is plugged into wall receptacle
Monitor fuse blows when power cord is plugged into wall recepta­cle.
All letters and indicators do not appear in display when power cord is first plugged into wall outlet.
Display does not operate prop­erly when STOP/CLEAR key is touched. (Buzzer should sound and ":" or time of day should ap­pear in display.)
Oven lamp does not light when door is opened.
Oven lamp does not go out when door is closed.
Oven lamp does not light in cook­ing cycle. (Lights when door is opened.)
Oven lamp does not light at all. Oven lamp lights but fan motor and
turntable motor do not operate. Oven does not go into cook cycle
when START pad is touched Oven seems to be operating but
little or no heat is produced in oven load. (Food incompletely cooked or not cooked at all at end of cook cycle.)
Oven goes into a cook cycle but extremely uneven heating is pro­duced in oven load (food).
Oven does not cook properly when programmed for Cooking Power 5 mode. (Operates prop­erly on Cooking Power 10 (HIGH) mode.)
Oven goes into COMPU DE­FROST but food is not defrosted well.
RERE A B C D E F F G H RERECK J CKCKCK L K M N I
SHORT IN POWER CORD
SHORT OR OPENED WIRING
MAGNETRON
POWER TRANSFORMER
H.V. RECTIFIER ASSEMBLY
HIGH VOLTAGE CAPACITOR
THERMAL CUT-OUT
SECONDARY INTERLOCK SYSTEM
PRIMARY INTERLOCK SWITCH
MONITOR SWITCH
MONITOR FUSE
OVEN LAMP OR SOCKET
COOLING FAN MOTOR
TURNTABLE MOTOR
TOUCH CONTROL PANEL
WRONG OPERATION
LOW VOLTAGE
DIRTY OVEN CAVITY
RELAY (RY1)
KEY UNIT
COMPU DEFROST
FOIL PATTERN ON PWB.
NOISE FILTER
9
R-312AW R-312AK
TEST PROCEDURES
PROCEDURE
LETTER
A MAGNETRON ASSEMBLY TEST
HIGH VOLTAGES ARE PRESENT DURING THE COOK CYCLE, SO EXTREME CAUTION SHOULD BE OBSERVED.
DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING.
To test for an open filament, isolate the magnetron from the high voltage circuit. A continuity check across the magnetron filament leads should indicate less than 1 ohm.
To test for a shorted magnetron, connect the ohmmeter leads between the magnetron filament leads and chassis ground. This test should indicate an infinite resistance. If there is little or no resistance the magnetron is grounded and must be replaced.
Power output of the magnetron can be measured by performing a water temperature rise test. This test should only be used if above tests do not indicate a faulty magnetron and there is no defect in the following components or wiring: silicon rectifier, high voltage capacitor and power transformer. This test will require a 16 ounce (453cc) measuring cup and an accurate mercury thermometer or thermocouple type temperature tester. For accurate results, the following procedure must be followed carefully:
1. Fill the measuring cup with 16 oz. (453cc) of tap water and measure the temperature of the water with a thermometer or thermocouple temperature tester. Stir the thermometer or thermocouple through the water until the temperature stabilizes. Record the temperature of the water.
2. Place the cup of water in the oven. Operate oven at POWER 10(HIGH) selecting more than 60 seconds cook time. Allow the water to heat for 60 seconds, measuring with a stop watch, second hand of a watch or the digital read-out countdown.¡
3. Remove the cup from the oven and again measure the temperature, making sure to stir the thermometer or thermocouple through the water until the maximum temperature is recorded.
4. Subtract the cold water temperature from the hot water temperature. The normal result should be 34.7 to 64.6˚F(19.3 to 35.9˚C) rise in temperature. If the water temperatures are accurately measured and tested for the required time period the test results will indicate if the magnetron tube has low power output (low rise in water temperature) which would extend cooking time or high power output (high rise in water temperature) which would reduce cooking time. Because cooking time can be adjusted to compensate for power output, the magnetron tube assembly should be replaced only if the water temperature rise test indicates a power output well beyond the normal limits. The test is only accurate if the power supply line voltage is 120 volts and the oven cavity is clean.
COMPONENT TEST
B POWER TRANSFORMER TEST
DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING.
Disconnect the primary input terminals and measure the resistance of the transformer with an ohmmeter. Check for continuity of the coils with an ohmmeter. On the R x 1 scale, the resistance of the primary coil should be less than 1 ohm and the resistance of the high voltage coil should be approximately 86.4 ohms; the resistance of the filament coil should be less than 1 ohm.
(HIGH VOLTAGES ARE PRESENT AT THE HIGH VOLTAGE TERMINAL, SO DO NOT ATTEMPT TO MEASURE THE FILAMENT AND HIGH VOLTAGE.)
C HIGH VOLTAGE RECTIFIER TEST
DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING.
Isolate the rectifier from the circuit. Using the highest ohm scale of the meter, read the resistance across the terminals and observe, reverse the leads to the rectifier terminals and observe meter reading. If a short is indicated in both directions, or if an infinite resistance is read in both directions, the rectifier is probably defective and should be replaced.
NOTE: Be sure to use an ohmmeter that will supply a forward bias voltage of more than 6.3 volts.
10
TEST PROCEDURES
R-312AW R-312AK
PROCEDURE
LETTER
D HIGH VOLTAGE CAPACITOR TEST
DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING.
If the capacitor is open, no high voltage will be available to the magnetron. Disconnect input leads and check for short or open between the terminals using an ohmmeter. Checking with a high ohm scale, if the high voltage capacitor is normal, the meter will indicate continuity for a short time and should indicate an open circuit once the capacitor is charged. If the above is not the case, check the capacitor with an ohmmeter to see if it is shorted between either of the terminals and case. If it is shorted, replace the capacitor.
E OVEN THERMAL CUT-OUT
A continuity check across the thermal cut-out terminals should indicate a closed circuit unless the temperature of the thermal cut-out reaches approximately 257˚F(125˚C). An open thermal cut-out indicates overheating of the oven, exchange the oven thermal cut-out and check inside of oven cavity and for improper setting of cooking time or operation of control unit. Check for restricted air flow through the vent holes of the oven cavity, especially the cooling fan and air guide.
MAGNETRON THERMAL CUT-OUT
A continuity check across the thermal cut-out terminals should indicate a closed circuit. If the temperature of the magnetron reaches approximately 203˚F(95˚C), the thermal cut-out opens. The thermal cut-out resets automatically below approximately 167˚F (75˚C). An open thermal cut-out indicates overheating of the magnetron. Check for restricted air flow to the magnetron, especially the cooling fan air guide.
CAUTION: IF THE THERMAL CUT-OUT INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE,
REPLACE THERMAL CUT-OUT.
COMPONENT TEST
F PRIMARY INTERLOCK SWITCH AND DOOR SWITCH TEST
Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal of the switch. The meter should indicated an open circuit with the door open and a closed circuit with the door closed. If improper operation is indicated, replace the primary interlock switch.
SECONDARY INTERLOCK SYSTEM TEST
DOOR SENSING SWITCH Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal of the switch, the meter should indicated an open circuit with the door open and a closed circuit with the door closed. If improper operation is indicated, replace the door sensing switch.
NOTE: If the door sensing switch contacts fail in the open position and the door is closed, the
cooling fan, turntable and oven light will be activated by RY1.
SECONDARY INTERLOCK RELAY Disconnect two (2) wire leads from the male tab terminals of the secondary Interlock relay. Check the state of the relay contacts using a ohmmeter. The relay contacts should be open. If the relay contacts are closed, replace the circuit board entirely or the relay itself.
G MONITOR SWITCH
Disconnect the oven from power supply. Before performing this test, make sure that the secondary interlock switch and the primary interlock relay are operating properly, according to the above Switch Test Procedure. Disconnect the wire lead from the monitor switch (COM) terminal. Check the monitor switch operation by using the ohmmeter as follows. When the door is open, the meter should indicate a closed circuit. When the monitor switch actuator is pushed by a screw driver through the lower latch hole on the front plate of the oven cavity with the door opened (in this condition the plunger of the monitor switch is pushed in), the meter should indicate an open circuit. If improper operation is indicated, the switch may be defective. After testing the monitor switch, re-connect the wire lead to the
SCREW DRIVER
monitor switch (COM) terminal and check the con­tinuity of the monior circuit.
11
RED
GRY
MONITOR SWITCH
OHMMETER
R-312AW
FUSE 20A
NOISE FILTER
NOISE SUPPRESSION COIL
LINE CROSS CAPACITOR
0.22µF / AC 250V
LINE BYPASS
CAPACITOR
0.0033µF / AC 125V
LINE BYPASS
CAPACITOR
0.0033µF / AC 125V
H
REDGRY
N
R-312AK
TEST PROCEDURES
PROCEDURE
LETTER
H BLOWN MONITOR FUSE
If the monitor fuse is blown when the door is opened, check the primary interlock switch and monitor switch according to the "TEST PROCEDURE" for those switches before replacing the blown monitor fuse.
CAUTION: BEFORE REPLACING A BLOWN MONITOR FUSE, TEST THE PRIMARY INTERLOCK
If the monitor fuse is blown by improper switch operation, the monitor fuse and the monitor switch must be replaced with "monitor fuse and switch assembly" part number FFS-BA012WRK0, even if the monitor switch operates normally. The monitor fuse and switch assembly is packed with 20 ampere fuse and switch.
I NOISE FILTER TEST
Disconnect the oven from power supply. Disconnect the lead wires from the terminal the noise filter. Using an ohmmeter, check between the terminals as described in the following table.
MEASURING POINT INDICATION OF OHMMETER
Between N and H Open circuit. Between terminal N and GRAY Short circuit. Between terminal H and RED Short circuit.
COMPONENT TEST
SWITCH AND MONITOR SWITCH FOR PROPER OPERATION.
If incorrect reading are obtained, replace the noise filter.
J TOUCH CONTROL PANEL ASSEMBLY TEST
The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore, unlike conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter and ohmmeter. In this service manual, the touch control panel assembly is divided into two units, Control Unit and Key Unit, and also the Control Unit is divided into two units, CPU Unit and Power Unit, and troubleshooting by unit replacement is described according to the symptoms indicated.
1. Key Unit. Note : Check key unit ribbon connection before replacement. The following symptoms indicate a defective key unit. Replace the key unit. a) When touching the pads, a certain pad produces no signal at all. b) When touching a number pad, two figures or more are displayed. c) When touching the pads, sometimes a pad produces no signal.
2. Control Unit The following symptoms indicate a defective control unit. Before replacing the control unit, perform the Key unit test (Procedure K) to determine if control unit is faulty.
2-1 In connection with pads.
a) When touching the pads, a certain group of pads do not produce a signal. b) When touching the pads, no pads produce a signal.
2-2 In connection with indicators
a) At a certain digit, all or some segments do not light up. b) At a certain digit, brightness is low. c) Only one indicator does not light. d) The corresponding segments of all digits do not light up; or they continue to light up. e) Wrong figure appears. f) A certain group of indicators do not light up. g) The figure of all digits flicker.
2-3 Other possible problems caused by defective control unit.
a) Buzzer does not sound or continues to sound. b) Clock does not operate properly.
12
TEST PROCEDURES
R-312AW R-312AK
PROCEDURE
LETTER
Note: When defective components, the Power Unit or Key Unit are replaced, the defective part or parts
K KEY UNIT TEST
If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable is making good contact, verify that the door sensing switch (stop switch) operates properly; that is the contacts are closed when the door is closed and open when the door is open. If the door sensing switch (stop switch) is good, disconnect the flat ribbon cable that connects the key unit to the control unit and make sure the door sensing switch is closed (either close the door or short the door sensing switch connecter). Use the Key unit matrix indicated on the control panel schematic and place a jumper wire between the pins that correspond to the STOP/CLEAR pad making momentary contact. If the control unit responds by clearing with a beep the key unit is faulty and must be replaced. If the control unit does not respond, it is a faulty and must be replaced. If a specific pad does not respond, the above method may be used (after clearing the control unit) to determine if the control unit or key pad is at fault.
COMPONENT TEST
c) Cooking is not possible.
must be properly packed for return in the shipping carton, with its cushion material, in which the new replacement part was shipped to you.
G 8 G 7 G 6 G 5 G 4 G 3 G 2 G 1
5
4
3
09876
START
MINUTE
PLUS
POWER
LEVEL
G12 G11 G10 G 9
COMPU
DEFROST
TIMER
CLOCK
FRESH
VEGETABLE
FROZEN
ROLL
/ MUFFIN
21
REHEAT
FRESH
ROLL
BEVERAGE
BAKED
POTATO
CASSEROLE
/ MUFFIN
POPCORN
DINNER
PLATE STOP
CLEAR
L RELAY TEST
Remove the outer case and check voltage between Pin No. 3 of the 2 pin connector (A) and the common terminal of the relay RY2 on the control unit with an A.C. voltmeter. The meter should indicate 120 volts, if not check oven circuit. RY1 and RY2 Relay Test
These relays are operated by D.C. voltage Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation.
DC. voltage indicated ............. Defective relay.
DC. voltage not indicated ........ Check diode which is connected to the relay coil. If diode is good, control
RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS
RY1 Approx. 14.0 D.C. Oven lamp / Turntable motor / Cooling fan motor RY2 Approx. 12.8 D.C. Power transformer
M COMPU DEFROST TEST
(1) Place one cup of water in the center of the turntable tray in the oven cavity. (2) Close the door, touch the " COMPU DEFROST " pad twice and touch the Number pad " 5 ". And
then touch the "START" pad. (3) The oven is in Compu Defrost cooking condition. (4) The oven will operate as follows
WEIGHT 1ST STAGE 2ND STAGE 3RD STAGE
LEVEL TIME LEVEL TIME LEVEL TIME
0.5lbs 70% 40sec. 50% 38sec. 30% 43sec.
unit is defective.
(5) If improper operation is indicated, the control unit is probably defective and should be checked.
13
R-312AW R-312AK
TEST PROCEDURES
PROCEDURE
LETTER
N PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD
(PWB) IS OPEN
To protect the electronic circuits, this model is provided with a fine foil pattern added to the primary on the PWB, this foil pattern acts as a fuse. If the foil pattern is open, follow the troubleshooting guide given below for repair. Problem: POWER ON, indicator does not light up.
STEPS OCCURRENCE CAUSE OR CORRECTION
1 The rated AC voltage is not present between Check supply voltage and oven power cord.
Pin No. 3 of the 2-pin connector (A) and the common terminal of the relay RY2.
2 The rated AC voltage is present at primary Low voltage transformer or secondary circuit defective.
side of low voltage transformer. Check and repair. 3 Only pattern at "a" is broken. *Insert jumper wire J1 and solder. 4 Pattern at "a" and "b" are broken. *Insert the coil RCILF2003YAZZ between "c" and "d".
NOTE: *At the time of making these repairs,
make a visual inspection of the varistor. Check for burned damage and examine the transformer with a tester for the presence of layer short-circuit (check the primary coil resistance which is ap­proximately 563 ± 10%). If any abnor­mal condition is detected, replace the defective parts.
COMPONENT TEST
VH
CN - A
c
3
(J1)
3
a
b
XH
(COM)
AC
d
HVT
RY2
14
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
R-312AW R-312AK
The touch control section consists of the following units. (1) Key Unit
(2) Control Unit (The Control Unit consists of Power Unit
and CPU Unit).
The principal functions of these units and the signals communicated among them are explained below.
Key Unit
The key unit is composed of a matrix, signals generated in the LSI are sent to the key unit through P73, P81, P82, P83, P90 and P91. When a key pad is touched, a signal is completed through the key unit and passed back to the LSI through P60 - P63 to perform the function that was requested.
Control Unit
Control unit consists of LSI, ACL circuit, indicator circuit, power source circuit, relay circuit, buzzer circuit, synchro­nizing signal circuit, absolute humidity sensor circuit and back light circuit.
1) ACL
This circuit generates a signal which resets the LSI to the initial state when power is supplied.
3) Power Source Circuit
This circuit generates voltages necessary in the control unit from the AC line voltage. In addition, the synchronizing signal is available in order to compose a basic standard time in the clock circuit.
Symbol Voltage Application
VC -5.3V LSI(IC1)
4) Relay Circuit
A circuit to drive the magnetron, fan motor, turntable motor and light the oven lamp.
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to emit audible sounds (key touch sound and completion sound).
6) Synchronizing Signal Circuit
The power source synchronizing signal is available in order to compose a basic standard time in the clock circuit. It accompanies a very small error because it works on commercial frequency.
7) Door Sensing Switch
A switch to “tell” the LSI if the door is open or closed.
2) Indicator Circuit
This circuit consists of 12 segments and 3 common electrodes using a Liquid Crystal Display.
8) Back Light Circuit
A circuit to drive the back light (Light emitting diodes
15
R-312AW R-312AK
DESCRIPTION OF LSI
LSI(IZA758DR)
The I/O signal of the LSI(IZA758DR) is detailed in the following table.
Pin No. Signal I/O Description
1-12 SEG0-SEG11 OUT Segment data signal.
Connected to LCD. The relation between signals are as follows: LSI signal (Pin No.) LCD (Pin No.) LSI signal (Pin No.) LCD (Pin No.)
SEG 0 (1) ................................ S12 SEG 6 (7)................................. S6
SEG 1 (2) ................................ S11 SEG 7 (8)................................. S5
SEG 2 (3) ................................ S10 SEG 8 (9)................................. S4
SEG 3 (4) .................................. S9 SEG 9 (10)............................... S3
SEG 4 (5) .................................. S8 SEG 10 (11)............................. S2
SEG 5 (6) .................................. S7 SEG 11(12).............................. S1
13 R60 IN Signal coming from touch key.
When either G12 line on key matrix is touched, a corresponding signal out of R73, R81­R83 and R90-R91 will be input into R60. When no key is touched, the signal is held at "H" level.
14 R61 IN Signal similar to R60.
When either G11 line on key matrix is touched, a corresponding signal will be input into R61.
15 R62 IN Signal similar to R60.
When either G10 line on key matrix is touched, a corresponding signal will be input into R62.
16 R63 IN Signal similar to R60.
When either G9 line on key matrix is touched, a corresponding signal will be input into R63.
17 AIN0 IN To input signal which communicates the door open/close information to LSI.
Door close "H" level signal (0V). Door open "L" level (-5V)
18-20 AIN1-AIN3 IN Terminal to change functions according to the Model.
By using the A/D converter contained in the LSI, DC voltage in accordance with the Model in operation is applied to set up its function.
21 VSS IN Power source voltage: -5V
VSS voltage of power source circuit input.
22 R70 OUT Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay (RY2). The signals holds "L" level during microwave cook­ing and "H" level while not cooking. In other cooking modes (variable cooking) the signal turns to "H" level and "L" level in repetition according to the power level.
OFF
P-HI
OFF OFF
P-70
ON
ON
24 sec.
8 sec.
H : GND
L : -5V H : GND
L : -5V
(ON and OFF times for other power level.)
23 PULSE OUT Signal to sound buzzer (2.0 kHz).
A: key touch sound. B: Completion sound.
0.1 sec.
A
2 sec.
B
24 R72 OUT Oven lamp, fan motor and turntable motor driving signal
To turn on and off shut off relay (RY1). The
16.7 msec.
square waveform voltage is delivered to the RY1 driving circuit and RY2 control circuit.
During cooking
H : GND
L : -5V H : GND
L : -5V
H : GND
L : -5V
16
Pin No. Signal I/O Description
16.7 msec.
H : GND
L : -5V
25 R73 OUT Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to R60 - R63 terminal while one of G8 line keys on key matrix is touched.
26 INT2 IN Signal synchronized with commercial power source frequency.
This is the basic timing for time processing of LSI.
27 R81 OUT Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to R60 - R63 terminal while one of G7 line keys on key matrix is touched.
28 R82 OUT Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to R60 - R63 terminal while one of G6 line keys on key matrix is touched.
29 R83 OUT Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to R60 - R63 terminal while one of G5 line keys on key matrix is touched.
30 R90 OUT Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to R60 - R63 terminal while one of G4 line keys on key matrix is touched.
R-312AW R-312AK
31 R91 OUT Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to R60 - R63 terminal while
one of G3 line keys on key matrix is touched. 32 R92 OUT Terminal not used. 33 XIN IN Internal clock oscillation frequency setting input.
The internal clock frequency is set by inserting the capacitor and resistor circuit with
respect to XOUT terminal. 34 XOUT OUT Internal clock oscillation frequency control output.
Output to control oscillation input of XIN. 35 RESET IN Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is supplied. Temporarily set
to "L" level the moment power is supplied, at this time the LSI is reset. Thereafter set at
"H" level. 36 HOLD IN/OUT Connected to GND. 37 VLC IN Signal synchronized with commercial power source frequency.
Signal similar to VSS. 38 COM1 OUT Common data signal: COM1.
Connected to LCD (Pin No. C1) 39 COM2 OUT Common data signal: COM2.
Connected to LCD (Pin No. C2) 40 COM3 OUT Common data signal: COM1.
Connected to LCD (Pin No. C3) 41 COM4 OUT Terminal not used. 42 VDD IN Power source voltage input terminal.
Connected to GND.
17
R-312AW R-312AK
SERVICING
1. Precautions for Handling Electronic Components
This unit uses CMOS LSI in the integral part of the circuits. When handling these parts, the following pre­cautions should be strictly followed. CMOS LSI have extremely high impedance at its input and output termi­nals. For this reason, it is easily influenced by the surrounding high voltage power source, static electricity charge in clothes, etc. and sometimes it is not fully protected by the built-in protection circuit. In order to protect CMOS LSI.
1) When storing and transporting, thoroughly wrap them in aluminium foil. Also wrap all PW boards containing them in aluminium foil.
2) When soldering, ground the technician as shown in the figure and use grounded soldering iron and work table.
approx. 1M ohm
2. Shapes of Electronic Components
Transistor 2SA933S
B
C
E
KRC243M
3. Servicing of Touch Control Panel
We describe the procedures to permit servicing of the touch control panel of the microwave oven and the precautions you must take when doing so. To perform the servicing, power to the touch control panel is avail­able either from the power line of the oven itself or from an external power source.
(1) Servicing the touch control panel with power supply
of the oven: CAUTION: THE HIGH VOLTAGE TRANSFORMER OF THE MI­CROWAVE OVEN IS STILL LIVE DURING SERVIC­ING PRESENTS A HAZARD.
Therefore, when checking the performance of the touch control panel, put the outer cabinet on the oven to avoid touching the high voltage transformer, or unplug the primary terminal (connector) of the high voltage trans­former to turn it off; the end of such connector must be insulated with an insulating tape. After servicing, be sure to replace the leads to their original locations.
A. On some models, the power supply cord between the
touch control panel and the oven itself is so short that the two can’t be separated. For those models, check and
repair all the controls (sensor-related ones included) of the touch control panel while keeping it connected to the oven.
B. On some models, the power supply cord between the
touch control panel and the oven proper is long enough that they may be separated from each other. For those models, therefore, it is possible to check and repair the controls of the touch control panel while keeping it apart from the oven proper; in this case you must short both ends of the door sensing switch (on PWB) of the touch control panel with a jumper, which brings about an operational state that is equivalent to the oven door being closed. As for the sensor-related controls of the touch control panel, checking them is possible if dummy resistor(s) with resistance equal to that of the controls are used.
(2)Servicing the touch control panel with power supply
from an external power source:
Disconnect the touch control panel completely from the oven proper, and short both ends of the door sensing switch (on PWB) of the touch control panel, which brings about an operational state that is equivalent to the oven door being closed. Connect an external power source to the power input terminal of the touch control panel, then it is possible to check and repair the controls of the touch control panel it is also possible to check the sensor­related controls of the touch control panel by using the dummy resistor(s).
4. Servicing Tools
Tools required to service the touch control panel assem­bly.
1) Soldering iron: 30W (It is recommended to use a soldering iron with a grounding terminal.)
2) Oscilloscope: Single beam, frequency range: DC-10MHz type or more advanced model.
3) Others: Hand tools
5. Other Precautions
1) Before turning on the power source of the control unit, remove the aluminium foil applied for preventing static electricity.
2) Connect the connectors of the key unit to the control unit being sure that the lead wires are not twisted.
3) After aluminium foil is removed, be careful that abnormal voltage due to static electricity etc. is not applied to the input or output terminals.
4) Attach connectors, electrolytic capacitors, etc. to PWB, making sure that all connections are tight.
5) Be sure to use specified components where high preci­sion is required.
18
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
CAUTION: DISCONNECT OVEN FROM POWER SUPPLY BEFORE REMOVING OUTER CASE.
DISCHARGE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING AFTER REMOVING OUTER CASE.
WARNING FOR WIRING
R-312AW R-312AK
To prevent an electric shock, take the following man­ners.
1. Before wiring,
1) Disconnect the power supply.
2) Open the door and wedge the door open.
3) Discharge the high voltage capacitor and wait for 60 seconds.
2. Don’t let the wire leads touch to the following parts;
1) High voltage parts: Magnetron, High voltage transformer, High voltage capacitor and High voltage rectifier assembly.
2) Hot parts: Oven lamp, Magnetron, High voltage transformer and Oven cavity.
OUTER CASE REMOVAL
To remove the components, procedure as follows.
1. Disconnect oven from power supply.
2. Remove four(4) screws from rear and one (1) screw along the right side of case.
3. Slide the entire case back out about 1 inch(3 cm) to free
POWER TRANSFORMER REMOVAL
3) Sharp edge: Bottom plate, Oven cavity, Waveguide flange, Chassis support and other metallic plate.
4) Movable parts (to prevent a fault) Fan blade, Fan motor, Switch, Switch lever, Open button.
3. Do not catch the wire leads in the outer case cabinet.
4. Insert the positive lock connector certainly until its pin is locked. And make sure that the wire leads should not come off even if the wire leads is pulled.
5. To prevent an error function, connect the wire leads correctly, referring to the Pictorial Diagram.
it from retaining clips on the cavity face plate.
4. Lift entire case from the unit.
CAUTION: DISCONNECT OVEN FROM POWER SUP-
PLY BEFORE REMOVING OUTER CASE.
1. Disconnect oven from power supply and remove outer case.
2. Discharge high voltage capacitor.
3. Disconnect wire leads from power transformer, magnetron and capacitor terminals.
4. Remove four (4) screws holding transformer to bottom plate right.
5. Remove transformer from bottom plate right.
6. Remove the one (1) terminal insulator and tube from filament lead (longer one) of power transformer.
Re-install
1. Install the terminal insulator to receptacle of filament
TERMINAL INSULATOR REPLACEMENT
1. Open covers of the terminal insulator by using small flat type screw driver.
2. Remove the receptacle from the terminal insulator.
3. Now, the terminal insulator is free.
Terminal  insulator
Flat type screw driver
lead (longer one) of power transformer.
2. Rest transformer on the bottom plate right with its primary terminals toward the oven face plate.
3. Secure transformer with four screws to bottom plate right.
4. Re-connect wire leads (primary and high voltage) to power transformer and filament leads of transformer to magnetron and high voltage capacitor. Refer to "PICTORIAL DIAGRAM".
5. Re-install outer case and check that oven is operating properly.
Installation
1. Insert the receptacle into terminal insulator.
2. Close covers of the terminal insulator, as shown below.
COVERS
RECEPTACLE
19
R-312AW R-312AK
MAGNETRON REMOVAL
Removal
1. Disconnect oven from power supply and remove outer case.
2. Discharge high voltage capacitor.
3. Disconnect wire leads from magnetron.
4. Remove the one (1) screw holding chassis support to magnetron.
5. Remove the chassis support from oven.
6. Carefully remove the two (2) screws holding magnetron to waveguide flange.
7. Lift up magnetron with care so that magnetron antenna is not hit by any metal object around antenna.
8. Now, the magnetron is free.
Re-install
1. Re-install the magnetron to waveguide flange with the two (2) screws diagonally as shown in Figure C-1.
2. Insert the two (2) tabs of the chassis support to the oven cavity front plate and the back plate.
3. Re-install the chassis support to magnetron with the one (1) screw.
POWER SUPPLY CORD REPLACEMENT
4. Reconnect the wire leads to the magnetron. Refer to "PICTORIAL DIAGRAM".
5. Re-install outer case and check that the oven is operating properly.
CAUTION: WHEN REPLACING MAGNETRON, BE SURE
THE R.F. GASKET IS IN PLACE AND MOUNT­ING SCREWS ARE TIGHTENED SECURELY
SCREWS
MAGNETRON
WAVEGUIDE FLANGE
Figure C-1. Magnetron replacement
Removal
1. Disconnect oven from power supply and remove outer case.
2. Discharge high voltage capacitor.
3. Disconnect the white and black wires of the power supply cord from the noise filter.
4. Remove the one (1) screw holding the earth wire of the power supply cord to the bottom plate right.
5. Remove the power supply cord from the oven cavity back plate.
Re-install
1. Insert the power supply cord into the oven cavity back plate.
2. Connect the white and black wires of the power supply cord into the terminal of noise filter, referring to the Pictorial Diagram.
3. Re-install the earth wire of the power supply cord to the bottom plate right with the one (1) screw.
HIGH VOLTAGE RECTIFIER AND HIGH VOLTAGE CAPACITOR REMOVAL
1. Disconnect oven from power supply and remove outer case.
2. Discharge high voltage capacitor.
3. Remove the power supply cord, referring the "POWER SUPPLY CORD REPLACEMENT".
4. Disconnect wire leads from the noise filter.
5. Remove one (1) screw holding the noise filter angle to the oven cavity back plate.
6. Remove the noise filter angle with noise filter from the oven cavity back plate.
7. Disconnect the high voltage wire B from the high voltage capacitor.
8. Disconnec t he high voltage wire of high voltage rectifier assembly from the magnetron.
Black wire
Power supply cord
Oven cavity back plate
White wire
Noise  filter
RED GRY
Green wire
Bottom plate right
H
N
Figure C-2. Power supply cord replacement
9. Remove one (1) screw holding capacitor holder to oven cavity rear plate.
10.Disconnect rectifier terminal from capacitor. High voltage rectifier assembly is now free.
11.Remove one (1) screw holding high voltage rectifier assembly to capacitor holder.
12.Remove capacitor holder. Capacitor is now free.
CAUTION: WHEN REPLACING HIGH VOLTAGE RECTI-
FIER AND HIGH VOLTAGE CAPACITOR, GROUND SIDE TERMINAL OF THE HIGH VOLTAGE RECTIFIER MUST BE SECURED FIRMLY WITH A GROUNDING SCREW.
20
R-312AW R-312AK
OVEN LAMP AND LAMP SOCKET REMOVAL
1. Disconnect oven from power supply and remove outer case.
2. Discharge high voltage capacitor.
3. Bend the tab of the partition angle holding the lamp socket.
4. Lift up the oven lamp socket.
5. Pull the wire leads from the oven lamp socket by pushing the terminal hole of the oven lamp socket with the small flat type screw driver.
6. Now, the oven lamp socket is free.
®
POSITIVE LOCK
Push the lever of positive lock® connector. Pull down on the positive lock® connector.
CAUTION: WHEN YOU CONNECTING THE POSITIVE
LOCK® CONNECTORS TO THE TERMINALS, INSTALL THE POSITIVE LOCK® SO THAT THE LEVER FACES YOU
CONNECTOR (NO-CASE TYPE) REMOVAL
Oven lamp socket
Terminal
Wire lead
Flate type small screw driver
Figure C-3. Oven lamp socket
Positive lock® connector
Lever
Figure C-4. Positive lock® connector
Terminal hole
Terminal
1
Push
2
Pull down
CONTROL PANEL ASSEMBLY REMOVAL
1. Disconnect oven from power supply and remove outer case.
2. Discharge high voltage capacitor.
3. Disconnect wire leads from the door sensing switch and the oven cavity front flange.
4. Disconnect the wire leads from panel components.
5. Make one (1) tab of the oven cavity front plate straight holding the control panel assembly to the oven flange.
6. Slide the control panel assembly upward and remove it.
7. Now, individual components can be removed.
NOTE: 1. Before attaching a new key unit, wipe off remaining
adhesive on the control panel frame surfaces completely with a soft cloth soaked in alcohol.
2. When attaching the key unit to the control panel frame, adjust the upper edge and right edge of the key unit to the correct position of control panel frame.
3. Stick the key unit firmly to the control panel frame by rubbing with soft cloth not to scratch.
CPU UNIT AND POWER UNIT NOTE: When soldering the CPU unit and the power unit,
make sure both the CPU unit and the power unit are parallel, as shown figure C-5.
Handle the CPU unit carefully so that the ribbon cable does not come off. Because the ribbon cable is sticked on the LCD and the printed wiring board only by heated paste.
CPU unit
Connector
Solder
These should be parallel
Power unit
Figure C-5. Side view of CPU unit and Power unit
Ribbon cable
Liquid Crystal
Display (LCD)
of CPU unit
Printed wiring board 
Figure C-6. CPU unit
TURNTABLE MOTOR REMOVAL
1. Disconnect oven from power supply.
2. Remove turntable and turntable support from oven cavity.
3. Lay the oven on it's backside. Remove the turntable motor cover by snipping off the material in four corner.
4. Where the corners have been snipped off bend corner areas flat. No sharp edge must be evident after removal of the turntable motor cover.
5. Disconnect wire leads from turntable motor. (See "Positive lock connector removal")
6. Remove two (2) screws holding turntable motor to oven cavity.
7. Now the turntable motor is free.
8. After replacement use the one (1) screw to fit the turntable motor cover.
21
R-312AW R-312AK
COOLING FAN MOTOR REMOVAL
1. Disconnect oven from power supply and remove outer case.
2. Discharge high voltage capacitor.
3. Disconnect the wire leads from the fan motor.
4. Remove one (1) screw holding the chassis support to magnetron. And remove chassis support.
5. Release the snap of the main wire harness from the fan duct.
6. Remove one (1) screw holding the fan duct assembly to oven cavity.
7. Release the main wire harness from the hole of the fan duct.
8. Release the fan duct from the waveguide flange.
9. Release the fan duct assembly from the oven cavity.
10.Remove the fan blade from the fan motor shaft according the following procedure.
1) Hold the edge of the rotor of the fan motor by using a pair of grove joint pliers.
CAUTION: * Make sure that any pieces do not enter the gap
between the rotor and the stator of the fan motor because the rotor is easily shaven by pliers and metal pieces may be produced.
* Do not touch the pliers to the coil of the fan motor
because the coil may be cut or injured.
* Do not disfigure the bracket by touching with the
pliers.
2) Remove the fan blade from the shaft of the fan motor by pulling and rotating the fan blade with your hand.
3) Now, the fan blade will be free.
CAUTION: * Do not reuse the removed fan blade because the
hole (for shaft) may be larger than normal.
11.Remove the two (2) screws holding the fan motor to the
Coil
fan duct.
12.Now, the fan motor is free. INSTALLATION
1. Install the fan motor to the fan duct with the two (2) screws.
2. Install the fan blade to the fan motor shaft according the following procedure.
1) Hold the center of the bracket which supports the shaft of the fan motor on the flat table.
2) Apply the screw lock tight into the hole (for shaft) of the fan blade.
3) Install the fan blade to the shaft of fan motor by pushing the fan blade with a small, light weight, ball peen hammer or rubber mallet.
CAUTION: * Do not hit the fan blade strongly when installed
because the bracket may be disfigured.
* Make sure that the fan blade rotates smooth after
installation.
* Make sure that the axis of the shaft is not slanted.
3. Catch three holes of fan duct on three tabs of the waveguide flange.
4. Install the fan duct assembly to the oven cavity with the one (1) screw.
5. Insert the snap of the main wire harness to the hole of the fan duct and insert the main wire harness into the hole of the fan duct.
6. Install one (1) tab of the chassis support to oven cavity front plate and install another tab of it to rear plate. And then screw chassis support to magnetron with one (1) screw.
7. Connect the wire leads to the fan motor, referring to the pictorial diagram.
Shaft
Center of bracket
Stator
Gap Bracket
Rotor
Groove joint pliers
Shaft
Axis
Stator
Side ViewRear View
Rotor
These are the position where should be pinched with pliers
Table
DOOR SENSING / THIRD DOOR/ PRIMARY INTERLOCK AND MONITOR SWITCHES REMOVAL
1. Disconnect oven from power supply and remove outer case.
2. Discharge high voltage capacitor.
3. Disconnect wire leads from the switches.
4. Remove two (2) screws holding latch hook to oven flange.
5. Remove latch hook assembly from oven flange.
6. Push outward on the two (2) retaining tabs holding switch in place.
7. Switch is now free. At this time switch lever will be free, do not lose it.
Re-install
1. Re-install each switch lever and interlock switch in its place. The primary interlock switch is in the lower position and the door sensing switch is in the upper position. The third door switch is in the lower position at the back of the latch hook. The monitor switch is in the upper position of the primary interlock switch.
2. Re-connect wire leads to each switch. Refer to pictorial diagram.
3. Secure latch hook (with two (2) mounting screws) to oven flange.
4. Make sure that the monitor switch is operating properly and check continuity of the monitor circuit. Refer to chapter "Test Procedure" and Adjustment procedure.
22
R-312AW
LATCH HOOK
DOOR SENSING SWITCH
MONITOR  SWITCH
THIRD DOOR  SWITCH
SWITCH LEVER
PRIMARY INTERLOCK  SWITCH
LATCH HEADS
R-312AK
DOOR SENSING / THIRD DOOR/ PRIMARY INTERLOCK AND MONITOR SWITCHES ADJUSTMENT
If the door sensing switch, primary interlock switch, third door switch and monitor switch do not operate properly due to a misadjustment, the following adjustment should be made.
1. Loosen the two (2) screws holding latch hook to the oven cavity front flange.
2. With door closed, adjust latch hook by moving it back and forth, and up and down. In and out play of the door allowed by the upper and lower position of the latch hook should be less than 0.5mm. The vertical position of the latch hook should be adjusted so that the door sensing switch, primary interlock switch and third door switch are activated with the door closed. The horizontal position of the latch hook should be adjusted so that the plunger of the monitor switch is pressed with the door closed.
3. Secure the screws with washers firmly.
4. Check the all switches operation. If each switch has not activated with the door closed, loosen screw and adjust the latch hook position.
After adjustment, check the following.
1. In and out play of door remains less than 0.5mm when in the latched position. First check upper position of latch hook, pushing and pulling upper portion of door toward the oven face. Then check lower portion of the latch hook, pushing and pulling lower portion of the door toward the oven face. Both results(play in the door)
should be less than 0.5mm.
2. The door sensing switch, third door switch and primary interlock switch interrupt the circuit before the door can be opened.
3. Monitor switch contacts close when door is opened.
4. Re-install outer case and check for microwave leakage around door with an approved microwave survey meter. (Refer to Microwave Measurement Procedure.)
Figure C-7. Latch Switch Adjustments
DOOR REPLACEMENT
REMOVAL
1. Disconnect oven from power supply.
2. Push the open button and open the door slightly.
3. Insert an putty knife (thickness of about 0.5mm) into the gap between the door stopper and the choke cover to free engaging parts as shown in Figure C-8.
4. Try the principles of the lever and lift up the door stopper.
5. Now, the door stopper is free from the door assembly.
6. Release two (2) pins of door panel from two (2) holes of upper and lower oven hinges by lifting up.
7. Now, door assembly is free from oven cavity.
8. Insert an putty knife (thickness of about 0.5mm) into the gap between the choke cover and door frame as shown in Figure C-8 to free engaging parts.
9. Try the principles of the lever and lift up the choke cover by inserting a putty knife as shown Figure C-8.
10.Release choke cover from door panel.
11.Now choke cover is free.
Door stopper
12.Release door panel from nine (9) tabs of door frame by
Choke Cover
11
12
10
9
8
Figure C-8. Door Disassembly
sliding door panel downward.
1
6
2
3
4
5
Door Frame
Putty Knife
13
7
13.Now, door panel with sealer film is free.
14.Tear sealer film from door panel.
15.Now, door panel is free.
16.Slide latch head upward and remove it from door frame with releasing latch spring from door frame and latch head.
17.Now, latch head and latch spring are free.
18.Remove door screen from door frame by releasing two (2) tabs.
19.Now, door screen is free.
RE-INSTALL
1. Re-install door screen to door frame by fitting two (2) tabs of door frame to two (2) holes of door screen.
2. Re-install the latch spring to the latch head. Re-install the latch spring to the door frame. Re-install latch head to door frame.
3. Re-install door panel to door frame by fitting nine (9) tabs of door frame to nine (9) holes of door panel.
4. Hold the door panel to the door frame by sliding the door panel upward.
5. Put sealer film on door panel. Refer to "Sealer Film" about how to handle new one.
6. Re-install choke cover to door panel by pushing.
7. Catch two (2) pins of door panel on two (2) hole of upper and lower oven hinges.
8. Re-install the door stopper to the door assembly.
Note: After any service to the door; (A) Make sure that door sensing switch and secondary
interlock switch are operating properly. (Refer to chapter "Test Procedures".).
(B) An approved microwave survey meter should be
used to assure compliance with proper microwave
23
R-312AW R-312AK
radiation emission limitation standards.
After any service, make sure of the following :
1. Door latch heads smoothly catch latch hook through latch holes and that latch head goes through center of latch hole.
2. Deviation of door alignment from horizontal line of cavity face plate is to be less than 1.0mm.
3. Door is positioned with its face pressed toward cavity face plate.
4. Check for microwave leakage around door with an approved microwave survey meter. (Refer to Microwave Measurement Procedure.)
Note: The door on a microwave oven is designed to act as
an electronic seal preventing the leakage of microwave energy from oven cavity during cook cycle. This function does not require that door be air­tight, moisture (condensation)-tight or light-tight. Therefore, occasional appearance of moisture, light or sensing of gentle warm air movement around oven door is not abnormal and do not of themselves, indicate a leakage of microwave energy from oven cavity.
Pin
Upper oven hinge
Door panel
Lower oven hinge
Pin
Lower  oven hinge
Door stopper
Choke cover
Figure C-9. Door Replacement
SEALER FILM
Installation
1. Put the adhesive tape on the backing film of the sealer film as shown in Fig. C-10.
2. Tear the backing film by pulling the adhesive tape.
3. Put the pasted side of the sealer film on the door panel
Sealer film
Backing film
Adhesive tape
Figure C-10. Sealer film
24
R-312AW R-312AK
1
A
POWER 
SUPPLY
CORD
BLK
GRN
WHT
B
REDBLK
OVEN
C
THERMAL CUT-OUT
WHT
RED
2
BLK
WHT
N
H
MAGNETRON
THERMAL CUT-OUT
3
GRYRED
GRY
RED
RED
RED
BLK
45
RECTIFIER H.V.
HIGH VOLTAGE
CAPACITOR
MAGNETRON
POWER 
TRANSFORMER
HIGH VOLTAGE COMPONENTS
BLK
WHT
6
A
B
C
D
E
NOTE:
OVEN LAMP 
AND SOCKET
Hot (RED) wire must be
F
G
BLUE 
MARK
connected to the
terminal with blue mark
on the oven light socket.
GRY
GRN
N.O.
COM.
DOOR
SENSING
SWITCH
GRY
GRN
SH-A
BLK
WHT
FAN MOTOR
WHT
CN-A
1
2
RED 3
WHT
RY2 (N.O.)
GRY
GRY
RY2 (COM)
RED
GRY
N.C.
COM.
MONITOR
SWITCH
BLK
NO
THIRD
DOOR
SWITCH
(OVEN SIDE)
BRN
COM.
RED
WHT
TURNTABLE
MOTOR
BRN
NO
PRIMARY
BLK
RED
RED
COM.
INTERLOCK
SWITCH
D
E
F
G
H
1
CONTROL UNIT
2
CN-G
IC1
SH-B
RY1
RY2
T1
PRIMARY
INTERLOCK 
RELAY
N.O.
CN-A
1
3
COM.
Figure S-1. Pictorial Diagram
3
45
25
H
6
R-312AW R-312AK
1
A
B
AC
C
D
A 3
2
T1
1
VRS1
2
d
a
b
(J1)
c
RY1
3
D1-D4 11ES1
3
D3
4
D4
VR
LD1-LD5
D1
D2
45
LD1 LD2 LD3 LD4 LD5
WH-1
V
R
R4 27
D5
C1 0.1µ/50v
D6
+ –
Q2 2SA933
R5 4.7k
C2 1000µ/25v
R3 910 1/2w
SP1
C 1
C 2
C 3
C 4
C 5
6
A
B
C
D
TURNTABLE MOTOR OVEN LAMP FAN MOTOR
E
MICRO
AC
F
G
A 1
N.O.
COM
RY2
D7
R6 3.3k
C 6
C 7
E
D8
C 8
C 9
Q3 KRC243M
F
SH-B
B 1
+
C5 10µ/35v
SH-A
B 2
G
J2
VR
H
1
NOTE
2
: IF NOT SPECIFIED, 1/4w ± 5% : IF NOT SPECIFIED, 1SS270A
Figure S-2. Power Unit Circuit
3
45
26
H
6
R-312AW R-312AK
1
A
B
LIQUID CRYSTAL DISPLAY
C
D
E
ON DEF. LBS. QTY. CHECK
0.1µ/50v C13
2SA1037AK Q10
R10 1k
+
2
C1 C2 C3
 S12 S11 S10 S9 S8 S7 S6 S5 S4 S3 S2 S1
R11 15k
UDZ4.3B ZD10
D10
C11 47µ/16v
C10 0.01µ/25v
3
0.01µ/25v C70
VDD
COM 4
COM 3
COM 2
COM 1
40
421
5
SEG 0
SEG 1
SEG 2
SEG 3
SEG 4
(J14)(J15) (J12)(J13) (J10)(J11)
C12 0.01µ/25v
R71 10kF
/50v 33p
C71
R92
R91
VLC
X IN
HOLD
X OUT
RESET
35
10
SEG 5
SEG 6
SEG 7
SEG 8
SEG 9
SEG10
SEG11
: 4.7k x 3 (J11),(J13),(J15)
R20 15k
45
R51 15k
R52 15k
R53 15k
R54 15k
C 6 C 5 C 4 C 3 C 2 C 1
R55 15k
R90
R83
R82
R81
R73
R72
INT 2
25
30
IC1 IZA758DR
15
R60
R61
R62
R63
AIN0
AIN1
AIN2
R70
PULSE
22
21
VSS
AIN3
C 7
R56 15k
C 8
54321
C 9
C61 330p/50v C62 330p/50v C63 330p/50v C64 330p/50v
R61 220k R62 220k R63 220k R64 220k
R57 15k
0.01µ/25v
C40
R40 15k
R41 4.7k
DINNER
POPCORN
BEVERAGE
REHEAT
CASSE-
FRESH
VEGETA-
COMPU
09876
START
MINUTE
C11
C10
R58 15k
STOP
PLATE
BAKED
FRESH
ROLL / 
ROLE
BLE
FROZEN
ROLL / 
TIMER
DEFROST
PLUS
POWER
C12
R59 15k
6
CLEAR
POTATO
MUFFIN
MUFFIN
CLOCK
LEVEL
KEY UNIT
R60 15k
A
B
C
D
E
Figure S-3. CPU Unit Circuit
F
G
C 1
C 2
H
NC
GND
1
R13 15k
R14 15k
C 3
VC
2
C20
Q30
KRA101S
0.1µ/50v
R12 15k
C 4
C 5
INT
BUZZER
3
27
C 6
RY1
Q22
KRA105S
Q20
KRA101S
D20
D40
NOTEH
C 7
C 8
C 9
RY2
(RY3)
DOOR
SWITCH
45
: IF NOT SPECIFIED, 1/10w ± 5%
: IF NOT SPECIFIED, 1SS355
6
F
G
H
R-312AW R-312AK
1
A
B
C
D
D7
0
SP1
2
3
45
LD1 LD2 LD3 LD4 LD5
DIP
1
CN - C
R5
2
3
9
D5
(C4)
R3
R6
4
5
(D9)
D8
BE
C5
Q3
(J3)
(J2)
6
0
0
D6
(C3)
(R2/J4)
E
B
(ZD1)
R4
B
(Q1)
(R1)
C2
WH-1
12
E
1
Q2
1
SH-B
1
(CN - B)
DOOR SW
6
WH-1
2
SH-A (GREEN)
2
A
B
C
D
OL FM AC
E
TTM
F
CN - A
G
H
RY1
13
13
T1
(1) (3)
VRS1
VH
XH
(COM)
AC
HVT
RY2
(J1)
DU
LOT NO.
1
3
OMIF
F
(7) (4)
OMIF
DU
E
7
6
C1 D4 D2 D1
4
D3
F
(RY3)
G
H
1
Figure S-4. Printed Wiring Board of Power Unit
2
3
45
28
6
R-312AW R-312AK
PARTS LIST
REF. NO. PART NO. DESCRIPTION Q'TY CODE
ELECTRIC PARTS
1- 1 QSW-MA110WRE0 1- 2 FPWBFA293WRK0 Noise filter 1 AX 1- 3 FFS-BA012WRK0 Monitor fuse and monitor switch assembly 1 AH 1- 4 RTHM-A078WRE0 Thermal cut-out 125 deg. 1 AL 1- 5 FACCDA074WRE0 Power supply cord 1 AW 1- 6 FH-DZA075WRK0 High voltage rectifier assembly 1 AS 1- 7 RC-QZA173WRE0 High voltage capacitor 1 AX 1- 8 RV-MZA197WRE0 Magnetron 1 BN 1- 8 RV-MZA222WRE0 Magnetron (Interchangeable) 1 BN 1- 9 RMOTEA338WRE0 Fan motor 1 AV 1-10 QSOCLA021WRE0 Oven lamp socket 1 AH 1-11 RLMPTA030WRE0 Oven lamp 1 AF 1-12 RMOTDA161WRE0 Turntable motor 1 AU 1-13 RTHM-A079WRE0 Thermal cut-out 95 deg. 1 AL 1-14 RTRN-A512WRE0 Power transformer 1 BM
2- 1 GCABUA631WRP0 Outer case cabinet [R-312AK] 1 BB 2- 1 GCABUA608WRP0 Outer case cabinet [R-312AW] 1 BB 2- 2 GDAI-A261WRW0 Bottom plate left 1 AP 2- 3 FDAI-A189WRY0 Bottom plate right 1 AX 2- 4 GLEGPA019WRE0 Foot 2 AD 2- 5 GLEGPA067WRF0 Leg 1 AE
3- 1 CPWBFA736WRK0 Power unit 1 BB 3- 1A QCNCMA244DRE0 2-pin connector (CN-A) 1 AB 3- 1B QCNCMA422DRE0 9-pin connector (CN-C) 1 AF 3- 1C FW-VZA195DRE0 Switch harness A (SH-A) 1 AD 3- 1D FW-VZA197DRE0 Switch harness B (SH-B) 1 AD 3- 1E FW-VZA196DRE0 Lead wire harness (WH-1) 1 AD 3- 1F LHLD-A171WRF0 LED holder 1 AE C1 RC-KZA087DRE0 Capacitor 0.1uF 50V 1 AB C2 VCEAB31EW108M Capacitor 1000uF 25V 1 AE C5 VCEAB31VW106M Capacitor 10uF 35V 1 AA D1-4 VHD11ES1///-1 Diode (11ES1) 4 AB D5-8 VHD1SS270A/-1 Diode (1SS270ATA) 4 AA LD1-5 VHPSLZ381A9-3 Light emitting diode 5 AC Q2 VS2SA933S//-3 Transistor (2SA933) 1 AB Q3 VSKRC243M//-3 Transistor (KRC243M) 1 AB R3 VRD-B12HF911J Resistor 910 ohm 1/2W 1 AA R4 VRD-B12EF270J Resistor 27 ohm 1/4W 1 AA R5 VRD-B12EF472J Resistor 4.7k ohm 1/4W 1 AA R6 VRD-B12EF332J Resistor 3.3k ohm 1/4W 1 AA RY1 RRLY-A021DRE0 Relay (OJSH112LM-UL) 1 AH RY2 RRLY-A094DRE0 Relay (OMIF-S-112LM) 1 AN SP1 RALM-A014DRE0 Buzzer (PKM22EPT-THAI) 1 AG T1 RTRNPA110DRE0 Transformer 1 AN VRS1 RH-VZA032DRE0 Varistor (10G471K) 1 AE 3- 2 DPWBFB611WRK0 CPU unit 1 BA 3- 3 FPNLCB277WRK0 Control panel frame with key unit [R-312AW] 1 BC 3- 3 FPNLCB281WRK0 Control panel frame with key unit [R-312AK] 1 BC 3- 3- 1 FUNTKA792WRE0 Key unit [R-312AW] 1 AY 3- 3- 1 FUNTKA795WRE0 Key unit [R-312AK] 1 AZ 3- 4 PSHEPA588WRE0 LED sheet 1 AM 3- 5 JBTN-B028WRF0 Open button [R-312AK] 1 AG 3- 5 JBTN-B029WRF0 Open button [R-312AW] 1 AG 3- 6 MSPRCA050WRE0 Open button spring 1 AB 3- 7 XEPSD30P08XS0 Screw: 3mm x 8mm 4 AA
4- 1 LANGQA456WRP0 Noise filter angle 1 AG 4- 2 LSTPPA162WRF0 Door stopper 1 AE 4- 3 PHOK-A095WRF0 Latch hook 1 AN 4- 4 LBNDKA099WRW0 Capacitor holder 1 AD 4- 5 NFANJA029WRE0 Fan blade 1 AL 4- 6 PDUC-A652WRP0 Fan duct 1 AU 4- 7 FOVN-A386WRT0 Oven cavity 1 BM 4- 8 LANGFA180WRW0 Chassis support 1 AM 4- 9 LANGQA452WRP0 Partition angle 1 AK
2nd interlock switch, door sensing switch
&
third door switch
CABINET PARTS
CONTROL PANEL PARTS
OVEN PARTS
3AK
29
R-312AW R-312AK
REF. NO. PART NO. DESCRIPTION Q'TY CODE
4-10 LANGQA454WRP0 MG thermo angle 1 AH 4-11 MLEVPA194WRF0 Switch lever 1 AG 4-12 NCPL-A045WRF0 Coupling 1 AH 4-13 PCUSGA385WRP0 Cushion 1 AK 4-14 PCOVPA275WRE0 Waveguide cover 1 AR 4-15 PCUSGA339WRP0 Cushion 1 AG 4-16 PCUSUA212WRP0 Cushion 1 AB 4-17 PCUSUA235WRP0 Cushion 1 AF 4-18 PCUSUA376WRP0 Cushion 1 AG 4-19 PCUSGA399WRE0 Cushion 1 AG 4-20 PPACGA084WRF0 TTM packing 1 AF 4-21 PCOVPA328WRP0 Safety cover side 1 AF 4-22 PCOVPA330WRP0 Thermo cover 1 AF
DOOR PARTS
5 CDORFA754WRK0 Door assembly [R-312AK] 1 BH 5 CDORFA758WRK0 Door assembly [R-312AW] 1 BG 5- 1 FDORFA303WRT0 Door panel 1 BA 5- 2 PSHEPA382WRE0 Sealer film 1 AH 5- 3 GWAKPA448WRR0 Door frame [R-312AK] 1 AW 5- 3 GWAKPA458WRR0 Door frame [R-312AW] 1 AY 5- 4 HPNL-A662WRE0 Door screen [R-312AK] 1 AK 5- 4 HPNL-A663WRR0 Door screen [R-312AW] 1 AL 5- 5 GCOVHA370WRF0 Choke cover 1 AM 5- 6 LSTPPA139WRF0 Latch head 1 AF 5- 7 MSPRTA084WRE0 Latch spring 1 AB 5- 8 PCUSUA481WRP0 Cushion 1 AB 5- 9 PCUSUA452WRP0 Cushion 1 AB 5-10 XCPSD40P08000 Screw : 4mm x 8mm 1 AA 5-11 XCPSD40P08WN2 Screw : 4mm x 8mm 1 AC
MISCELLANEOUS
6- 1 FROLPA079WRK0 Turntable support 1 AQ 6- 2 NTNT-A084WRE0 Turntable tray 1 AR 6- 3 FW-VZB584WRE0 Main wire harness 1 AW 6- 4 QW-QZA150WRE0 High voltage wire B 1 AF 6- 5 PZET-A012WRE0 Terminal insulator 1 AB 6- 6 TCAUAA233WRR0 User caution label 1 AC 6- 7 TCAUAA234WRR0 Monitor caution label 1 AC 6- 8 TCADCA630WRR0 Instruction book 1 AF 6- 9 TSPCNC468WRR0 Rating label [R-312AK] 1 AC 6- 9 TSPCNC469WRR0 Rating label [R-312AW] 1 AC 6-10 LHLDWA012WRE0 Purse lock L 1 AB 6-11 PZET-A032WRE0 Terminal insulator 2 AD 6-12 TCAUAA235WRR0 Service caution 1 AC
SCREWS,NUTS AND WASHERS
7- 1 XFPSD40P08K00 Screw : 4mm x 8mm 10 AA 7- 2 XFPSD30P06000 Screw : 3mm x 6mm 1 AA 7- 3 XHTSD40P08RV0 Screw : 4mm x 8mm 4 AA 7- 4 XOTSF40P08000 Screw : 4mm x 8mm [R-312AK] 1 AA 7- 4 XOTSE40P08000 Screw : 4mm x 8mm [R-312AW] 1 AA 7- 5 XOTSD40P12RV0 Screw : 4mm x 12mm 8 AA 7- 6 XOTSD40P12000 Screw : 4mm x 12mm 12 AA 7- 7 XOTSD40P08000 Screw : 4mm x 8mm 2 AA
HOW TO ORDER REPLACEMENT PARTS
To have your order filled promptly and correctly, please furnish the following information.
1. MODEL NUMBER 2. REF. NO. 3. PART NO. 4. DESCRIPTION
Order Parts from the authrized SHARP parts Distributor for your area. Defective parts required return should be returned as indicated in the Service Policy.
30
INFORMATION FOR PARTS CHANGE
The instruction book will be changed from June 1997 production (Serial number from 9706xxxxx).
Interchangeability
A. OLD
REF.NO.
6- 8 Instruction book TCADCA630WRR0 1 TCADCA642WRR0 1 A June/'97
NEW B. OLD
DESCRIPTION OLD No.
NEW C. OLD
NEW D. OLD NEW
REPLACEMENT PART NO. Interchange- EFFECTIVE
Q'ty
NEW No.
Q'ty
ability FROM CODE
R-312AW R-312AK
PACKING AND ACCESSORIES
INTO THE OVEN CAVITY
DOOR PROTECTION SHEET SPADPA204WRE0
6- 8 INSTRUCTION BOOK & PRINTING MATTER
6- 2 TURNTABLE TRAY
6- 1 TURNTABLE SUPPORT
TRAY PACK SPADFA397WRE0
TOP PAD ASSEMBLY FPADBA341WRK0
CABINET COVER (R-312AK only) SPAKHA003WRE0
PLASTIC BAG SSAKHA034WRE0
BOTTOM PAD ASSEMBLY FPADBA342WRK0
Not replaceable items.
31
PACKING CASE R-312AK: SPAKCC911WRE0  R-312AW: SPAKCC912WRE0  
R-312AW R-312AK
1
A
OVEN AND CABINET PARTS
B
C
D
4-17
2
4-18
1-11
4-9
6-7
4-22
1-4
3
7-5
1-10
7-2
4-10
1-13
7-3
45
2-1
7-1
1-8
6-12
4-16
1-5
6
A
7-5
B
7-5
C
7-4
D
4-7
E
6-9
4-12
6-6
F
G
4-14
7-6
2-4
7-6
H
2-2
2-5
7-6
1-12
7-6
7-6
4-20
7-1
7-1
7-6
4-11
7-5
7-5
2-4
1-1
4-15
7-6
4-13
4-3
1-14
7-6
2-3
1-1
4-4
1-1
4-19
7-6
1-3
7-1
1-9
7-5
1-5
6-1
7-3
7-1
7-3
6-2
1-7
1-6
7-1
4-8
4-6
4-5
4-1
7-3
7-7
1-3
1-2 7-1
4-21
E
7-7
F
G
H
1
2
3
32
45
6
R-312AW R-312AK
1
A
B
C
CONTROL PANEL PARTS
2
3 - 3
3-3-1
3 - 5
3 - 6
3
3 - 7
3-1F
3 - 4
3 - 2
45
3 - 7
3 - 7
3 - 1
4-2
5
5-5
6
A
B
C
D
E
F
G
DOOR PARTS
6-3
5-3
5-8
5-4
5-1
5-7
5-11
5-9
5-2
5-10
5-6
MISCELLANEOUS PARTS
D
E
F
G
H
Actual wire harness may be different from illustration.
1
2
(HIGH VOLTAGE TRANSFORMER)
6-4
6-5
3
33
(CAPACITOR)
6-11
6-10
45
H
6
R-312AW R-312AK
34
'97 SHARP CORP. (3U0.600E) Printed in Japan
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