Sharp R-22GV User manual

SERVICE MANUAL
SHARP ELECTRONICS CORPORATION
Service Headquarters: Sharp Plaza, Mahwah, New Jersey 07430-2135
R-22GV
R-22GT
R-23GT
R-24GT
S7508R24GT///
R-22GV
R-22GT
R-23GT
R-24GT
MODELS
Intheinterestofuser-safetytheovenshouldberestoredtoitsoriginal
condition and only parts identical to those specified should be used.
R-24GT
COMMERCIAL
MICROWAVE OVEN
TABLE OF CONTENTS Page
PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICE TO
AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY ...................INSIDE FRONT COVER
BEFORE SERVICING ...........................................................................................................................................1
MICROWAVE MEASUREMENT PROCEDURE ...................................................................................................2
FOREWORD..........................................................................................................................................................3
PRODUCT SPECIFICATIONS ..............................................................................................................................4
GENERAL INFORMATION...................................................................................................................................4
OPERATION..........................................................................................................................................................6
TROUBLE SHOOTING GUIDE/ TEST PROCEDURE ........................................................................................11
TOUCH CONTROL PANEL .................................................................................................................................19
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ................................................................28
PICTORIAL DIAGRAM ........................................................................................................................................33
CONTROL PANEL CIRCUIT ...............................................................................................................................35
PRINTED WIRING BOARD .................................................................................................................................39
PARTS LIST ........................................................................................................................................................40
PACKING AND ACCESSORIES .........................................................................................................................46

R-22GV
R-22GT
R-23GT
R-24GT
PRECAUTIONSTO BE OBSERVED BEFORE AND
DURING SERVICINGTO AVOID POSSIBLE
EXPOSURETO 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.
R-22GV

1
R-22GV
R-22GT
R-23GT
R-24GT
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.
ServicepersonnelshouldinformSHARPELECTRONICSCORPORATIONofanycertifiedunitfound
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.

2
R-22GV
R-22GT
R-23GT
R-24GT MICROWAVE MEASUREMENT PROCEDURE
A. Requirements:
1) Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven
shouldnotexceed1mW/cm2atanypoint5cmormorefromtheexternalsurfaceoftheoven,measuredpriortoacquisition
bya purchaser,and thereafter(throughthe usefullifeof theoven),5 mW/cm2at anypoint5cm ormorefrom theexternal
surface of the oven.
2) Safetyinterlockswitches:Theprimaryinterlockrelayanddoorsensingswitchshallpreventmicrowaveradiationemission
in excess of the requirement as mentioned above, and secondary interlock switch shall prevent microwave radiation
emission in excess of 5 mW/cm2at 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:
Surveyinstruments thatcomply withthe requirementfor instrumentationas prescribedby the performancestandard
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.
Theplacingofthisstandardloadintheovenisimportantnotonlytoprotecttheoven,butalsotoinsurethatanyleakage
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) Grasptheprobeofthesurveyinstrumentandholditperpendiculartothegapbetweenthedoorandthebodyoftheoven.
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) Checkforleakageatthedoorscreen,sheetmetalseamsandotheraccessiblepositionswherethecontinuityofthemetal
has been breached (eg., around the switches, indicator, and vents).
Whiletestingforleakagearoundthedoorpullthedoorawayfromthefrontoftheovenasfarasispermittedbytheclosed
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.

3
R-22GV
R-22GT
R-23GT
R-24GT
SERVICE MANUAL
COMMERCIAL
MICROWAVE OVEN
R-22GV/ R-22GT/ R-23GT/ R-24GT
FOREWORD
This Manual has been prepared to provide Sharp Electronics
Corp. Service Personnel with Operation and Service Informa-
tion for the SHARP MICROWAVE OVENS, R-22GV, R-22GT,
R-23GT, R-24GT.
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.
SHARP ELECTRONICS CORPORATION
SHARP PLAZA, MAHWAH,
NEW JERSEY 07430-2135
PRODUCT DESCRIPTION
GENERAL INFORMATION
OPERATION
TROUBLESHOOTING GUIDE
AND TEST PROCEDURE
TOUCH CONTROL PANEL
COMPONENT REPLACEMENT AND
ADJUSTMENT PROCEDURE
WIRING DIAGRAM
PARTS LIST

4
R-22GV
R-22GT
R-23GT
R-24GT SPECIFICATION
ITEM DESCRIPTION
Power Requirements 120 Volts / 2.0 KW (R-22GV, R-22GT) Approx. 17.7A
230/208 Volts / 2.5 kW (R-23GT) Approx. 13A at 208V, 11.9A at 230V
230/208 Volts / 2.9 kW (R-24GT) Approx. 14 A at 208V, 13.2A at 230V
60 Hertz / Single phase, 3 wire grounded
Power Output 1200 W (R-22GV, R-22GT)/ 1600 W (R-23GT)/ 1800 W (R-24GT)
(IEC-705 TEST PROCEDURE) Operating frequency of 2450MHz
Case Dimensions Width 20-1/8" Height 13-1/4" Depth 18-1/2"
Cooking Cavity Dimensions Width 13" Height 7-1/8" Depth 13"
Control Complement Touch Control System
Digital Display
10 Number Pads
STOP/CLEAR pad
START pad
SELECTAPOWER pad (Power level: 0 to 100%; except R-22GV)
SELECTATIME pad
DOUBLE QUANTITY pad
EXPRESS DEFROST pad
Memory SET pad
Memory CHECK pad
SIGNAL pad
Weight Approx. 57 lbs/ 26 kg (R-22GV, R-22GT)/ Approx. 63 lbs/ 29 kg (R-23GT)
Approx. 66 lbs/ 30 kg (R-24GT)
Safety Standard UL Listed FCC Authorized
DHHS Rules, CFR, Title 21, Chapter 1, Subchapter J
NSF Certified
GENERAL INFORMATION
GROUNDING INSTRUCTIONS
This appliance must be grounded. In the event of an electrical short circuit, grounding reduces the risk of electric shock by
providing an escape wire for the electric current. This appliance is equipped with a cord having a grounding wire with a
grounding plug. The plug must be plugged into an outlet that is properly installed and grounded.
WARNING: Improper use of the grounding plug can result in a risk of electric shock. The electrical requirements are 120
Volt, 60 Hz AC only, 20 Amp or more (R-22GV,R-22GT); 230/208 Volt, 60 Hz, AC only, 15 Amp or more (R-
23GT)and20Ampormore(R-24GT)fusedelectricalsupply.Itisrecommendedthataseparatecircuitserving
only this appliance be provided. When installing this appliance, observe all applicable codes and ordinances.
If it is necessary to use an extension cord, use only a 3-wire extension cord that has a 3-blade grounding plug
anda3-slotreceptaclethatwillaccepttheplugontheappliance.Themarkedratingoftheextensioncordshould
be AC 120 Volt 20 Amp (R-22GV,R-22GT), AC 230/208 Volt 15 Amp (R-23GT), AC230/208 Volt 20 Amp (R-
24GT).
Receptacle Box Cover
3-Pronged plug
(6-15P)
3-Pronged, Receptacle
(6-20R)
Receptacle Box Cover
3-Pronged plug
(6-15P)
3-Pronged, Receptacle
(6-15R)
Receptacle Box Cover
3-Pronged plug
(5-20P)
3-Pronged, Receptacle
(5-20R)
230/208V15A
R-23GT 230/208V20A R-24GT
120V 20A
R-22GV, R-22GT

5
R-22GV
R-22GT
R-23GT
R-24GT
VOLTAGE SELECT
The R-23GT and the R-24GT have been preset for 230V opera-
tion.
If you need to change this oven for 208V operation, follow
instructions below.
1. Unplug oven.
2. Remove one screw(A) from the Voltage Select Cover located
on back of the oven near the bottom.
3. Remove the Voltage Select Cover and rotate 180 degrees.
4. ReinstalltheVoltageSelectCoverusingonescrew(A)removed
in Step 2.
5. Plug power cord into wall outlet.
Your oven is now ready for 208V, 60Hz operation.
Note: If “EE4” or “EE5” appear in the lighted digital display, a
voltage adjustment must be made.
Power supply 
cord
230 V
230 V 208 V
208 V
(A)
OVEN DIAGRAM
1. Touch control panel
2. Door latch openings
3. Ceramic shelf
4. Splash cover
5. Oven light
6. Air intake filter
7. Air intake openings
8. Door seals and sealing surfaces
9. Door hinges
10.Oven door with see-through window
11.Door latches
12.Door handle
13.Service window for replacing the oven light bulb.
14.Ventilation openings
15.Power supply cord
16.Mounting plate
17.Screw for mouning plate
18.Voltage select cover (R-23GT/R-24GT)
4
1
5 2 9 3
678
10
11
12
15
14
13
16
17
18
19.DOUBLE QUANTITY pad
20.EXPRESS DEFROST pad
21.Ten number pads for time and
memory programming
22.SELECTATIME pad
23.STOP/CLEAR pad; touch to stop
operation of oven and clear
remaining heating time
24.SELECTAPOWER pad for setting
variable power level
25.START pad; touch to operate oven
after door is closed and time is set
26.SET pad for setting memory
27.CHECK pad for checking memory
28.SIGNALpadforsettingsignalsound
Accessory: Menu labels
R-22GT, R-23GT, R-24GTR-22GV
START
SELECTA
TIME STOP
CLEAR
1
2
3
4
5
6
7
8
9
0
DOUBLE
QUANTITY EXPRESS DEFROST
SET CHECK SIGNAL
DEF ON NO. X2 CHECK
20
21
23
25
28
26
22
19
27
DOUBLE
QUANTITY EXPRESS DEFROST
1
11
2
12
3
13
4
14
5
15
6
16
7
17
8
18
9
19
0
20
SELECTATIME STOP/CLEAR
SELECTAPOWER START
SET CHECK SIGNAL
DEF ON NO. X2 CHECK
20
21
23
25
28
26
24
22
19
27

6
R-22GV
R-22GT
R-23GT
R-24GT OPERATION
DESCRIPTION OF OPERATING SEQUENCE
The following is a description of component functions during
oven operation.
OFF CONDITION
Closing the door activates the door sensing switch and
secondary interlock switches (1), (2). (In this condition, the
monitor switches (1) & (2) contacts are opened.)When the
oven is plugged in, and the rated voltage is supplied to the
control unit, (figure O-1), the display will show " . ".
IDLE CONDITION
When the door is opened, the contacts of the door sensing
switch open, initiating the following:
1. A signal is input to the control unit energizing the coil of
shut-off relay (RY-1).
2. The shut-off relay (RY-1) contacts close completing
circuitstoturnontheovenlamp,blowermotorandstirrer
motors.
3. If the door remains open, 60 seconds later the control
unit de-energizes shut-off relay (RY-1) turning off the
oven lamp, blower motor and stirrer motors.
When the door is closed, the door sensing switch contacts
close. With the closing of the door sensing switch contacts,
an additional circuit is provided which will permit the opera-
tion of the oven when one of the touch pads is depressed.
Since the control is enabled through the door sensing
switch, the door must be closed before the touch pads will
beeffective.Whenthe dooris closed,afull 60second IDLE
condition is always provided for selecting and pressing the
desired touch pads. A 60 second IDLE condition will also
follow the end of each cook cycle.
COOKING CONDITION
When the door is closed from the open position and Memory
pad is touched the, following will occur:
1. The contacts of relays are closed and components
connected to the relays are turned on (For details, refer
to Figure O-3)
2. Rated voltage is supplied to the primary winding of the
power transformer and is converted to about 3.3 volts
(forR-22GV, R-22GT) / 3.1volts (forR-23GT, R-24GT)
output on the filament winding, and approximately 2000
volts(forR-22GV,R-22GT)/ 2040volts(forR-23GT,R-
24GT) on the high voltage winding.
3. The filament winding voltage heats the magnetron
filamentandtheH.V.windingvoltageissenttoavoltage
doubler circuit.
4. The microwave energy produced by the magnetron is
channelled through the waveguide into the cavity feed-
box, and then into the cavity where the food is placed to
be cooked.
5. Uponcompletionofthecookingtime, theovenwillrevert
to the IDLE condition.
6. When the door is opened during a cook cycle, monitor
switches (1) & (2), door sensing switch, secondary
interlock switches (1), (2) and primary interlock relays
(1), (2) are activated with the following results. The
circuitstothehighvoltagecomponentsarede-energized,
and the digital read-out displays " . " and cooking is
cancelled (in the case of Memory cooking).
7. The monitor switch (1) is electrically monitoring the
operation of the secondary interlock switch (1) and
primary interlock relay (1), and monitor switch (2) is
electrically monitoring the operation of the secondary
interlock switch (2) and primary interlock relay (2), and
monitor switches (1), (2) are mechanically associated
with the door so that it will function in the following
sequence.
(1)Whenthedooropensfromaclosedposition,thecontacts
of the primary interlock relays (1), (2) and secondary
interlockswitches(1),(2)open. Thenthemonitorswitch
contacts close.
(2)When the door is closed from the open position, the
monitorswitches(1),(2)contactsfirstopen,andthenthe
contacts of the secondary interlock switches (1), (2)
close.
Ifthesecondaryinterlockswitches(1),(2)andprimaryinterlock
relays (1), (2) fail with their contacts closed when the door is
opened,theclosingofthemonitorswitches(1),(2)contactswill
form a short circuit through the monitor fuse, secondary inter-
lock switches (1), (2) and primary interlock relays (1), (2),
causing the monitor fuse to blow.
VARIABLE POWER COOKING
( EXCEPT R-22GV)
When Variable Cooking Power is programmed, the rated
voltageA.C.issuppliedtothe powertransformerintermittently
through the contacts of relay (RY-2, RY-3). Relays RY-2 and
RY-3areoperated by thecontrol unit withinan interval second
time base. Microwave power operation is as follows:
POWER LEVEL ON TIME OFF TIME
100% 32 sec. 0 sec.
90% 30 sec. 2 sec.
80 % 26 sec. 6 sec.
70% 24 sec. 8 sec.
60% 22 sec. 10 sec.
50% 18 sec. 14 sec.
40% 16 sec. 16 sec.
30% 12 sec. 20 sec.
20% 8 sec. 24 sec.
10% 6 sec. 26 sec.
0% 0 sec. 32 sec.
Note: TheON/OFFtimeratiodoesnotexactlycorrespond
with the percentage of microwave power, because
approx. 2 seconds are needed for heating of the
magnetron filament.
Note: R-22GV has only 100% power level.

7
R-22GV
R-22GT
R-23GT
R-24GT
TWO MAGNETRON OPERATION SYSTEM
Twomagnetrons(1), (2)are equippedinorderto gethigher
microwave power output. The primary windings of the
power transformers (1), (2) are connected so that each
magnetron can be oscillated alternatively according to the
frequency of the power supply. Refer to the Figure B-1.
Figure O-1. R-23GT/24GT Oven SChematic-OFF Condition (208 VCondition)
Figure O-1. R-22GV/GT Oven SChematic-OFF Condition
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED OR 1 MINUTE AFTER COOK OFF
2. " . " APPEARS ON DISPLAY
COMMERCIAL
FREQUENCY
(60HZ)
POWER OUTPUT
BY MAGNETRON 1
POWER OUTPUT
BY MAGNETRON 2
OPERATION OF
MAGNETRON
Figure B-1. Operation of Magnetron
FUSE 20A
OVEN LAMP
BLOWER MOTOR
120V 60Hz
MAGNETRON (1) (UPPER)
BM
STIRRER MOTOR STIRRER MOTOR
SM SM
OL
H3 H1
MAGNETRON THERMISTOR
INTAKE  THERMISTOR
BLK
WHT
GRY
GRY
DOOR SENSING
SWITCH
A1 A3 B2 B1
A7
RY2 RY3
OVEN 
THERMAL
CUT-OUT
BLOWER
MOTOR 
THERMAL
CUT-OUT
SECONDARY
INTERLOCK
SWITCH (1)
MAGNETRON
THERMAL
CUT-OUT (1)
(UPPER)
PRIMARY
INTERLOCK
RELAY (2)
B3
OVEN THERMISTOR
D1D3
TAB2 TAB1
PRIMARY
INTERLOCK
RELAY (1)
MAGNETRON
THERMAL
CUT-OUT (2)
(LOWER)
YLW
BLK
MONITOR SWITCH (1) MONITOR SWITCH (2)
WHT/GRY GRY
YLW BLK
POWER
TRANSFORMER (1) 
(FRONT)
CAPACITOR (1)
0.75µF
CAPACITOR (2)
0.75µF
POWER
TRANSFORMER (2) 
(REAR)
RECTIFIER (1) 
RECTIFIER (2) 
BLK
ORG
MAGNETRON (2) (LOWER)
GRN
RY1
SECONDARY
INTERLOCK
SWITCH (2)
FUSE 20A
OVEN LAMP
BLOWER MOTOR
208/230V 60Hz
MAGNETRON (1) (UPPER)
BM
STIRRER MOTOR
SM SM
OL
H3 H1
MAGNETRON THERMISTOR
INTAKE  THERMISTOR
BLKWHT
DOOR SENSING
SWITCH
A1 A3 B2 B1
A7
RY2 RY3
OVEN 
THERMAL
CUT-OUT
BLOWER
MOTOR 
THERMAL
CUT-OUT
MAGNETRON
THERMAL
CUT-OUT (1)
(UPPER)
PRIMARY
INTERLOCK
RELAY (2)
B3
OVEN THERMISTOR
D1D3
TAB2 TAB1
PRIMARY
INTERLOCK
RELAY (1)
MAGNETRON
THERMAL
CUT-OUT (2)
(LOWER)
RED
PNK
MONITOR SWITCH (2) MONITOR SWITCH (1)
GRY
WHT
PNK RED
POWER
TRANSFORMER (1) 
(FRONT)
CAPACITOR (1)
0.94µF
CAPACITOR (2)
0.94µF
POWER
TRANSFORMER (2) 
(REAR)
RECTIFIER (1) 
RECTIFIER (2) 
MAGNETRON (2) (LOWER)
RY1
A5
WHT/GRY
OL
VOLTAGE SELECT SWITCH (V.S.SW) (2)
COM
NC
COM
NC
V.S.SW (1)
COM
NC
NC
COM
V.S.SW (4)
V.S.SW (3)
SECONDARY
INTERLOCK
SWITCH (1)
SECONDARY
INTERLOCK
SWITCH (2)
BLK RED

8
R-22GV
R-22GT
R-23GT
R-24GT
SCHEMATIC
NOTE: CONDITION OF OVEN
1. FOR 1MINUTE AFTER DOOR OPENED.
2. " . " APPEARS ON DISPLAY.
Figure O-2. R-23GT/24GT Oven SChematic-IDLE Condition (208 VCondition)
FUSE 20A
OVEN LAMP
BLOWER MOTOR
208/230V 60Hz
MAGNETRON (1) (UPPER)
BM
STIRRER MOTOR
SM SM
OL
H3 H1
MAGNETRON THERMISTOR
INTAKE  THERMISTOR
BLKWHT
DOOR SENSING
SWITCH
A1 A3 B2 B1
A7
RY2 RY3
OVEN 
THERMAL
CUT-OUT
BLOWER
MOTOR 
THERMAL
CUT-OUT
MAGNETRON
THERMAL
CUT-OUT (1)
(UPPER)
PRIMARY
INTERLOCK
RELAY (2)
B3
OVEN THERMISTOR
D1D3
TAB2 TAB1
PRIMARY
INTERLOCK
RELAY (1)
MAGNETRON
THERMAL
CUT-OUT (2)
(LOWER)
RED
PNK
MONITOR SWITCH (2) MONITOR SWITCH (1)
GRY
WHT
PNK RED
POWER
TRANSFORMER (1) 
(FRONT)
CAPACITOR (1)
0.94µF
CAPACITOR (2)
0.94µF
POWER
TRANSFORMER (2) 
(REAR)
RECTIFIER (1) 
RECTIFIER (2) 
MAGNETRON (2) (LOWER)
RY1
A5
WHT/GRY
OL
VOLTAGE SELECT SWITCH (V.S.SW) (2)
COM
NC
COM
NC
V.S.SW (1)
COM
NC
NC
COM
V.S.SW (4)
V.S.SW (3)
SECONDARY
INTERLOCK
SWITCH (1)
SECONDARY
INTERLOCK
SWITCH (2)
BLK RED
Figure O-2. R-22GV/22GT Oven SChematic-IDLE Condition
FUSE 20A
OVEN LAMP
BLOWER MOTOR
120V 60Hz
MAGNETRON (1) (UPPER)
BM
STIRRER MOTOR STIRRER MOTOR
SM SM
OL
H3 H1
MAGNETRON THERMISTOR
INTAKE  THERMISTOR
BLK
WHT
GRY
GRY
DOOR SENSING
SWITCH
A1 A3 B2 B1
A7
RY2 RY3
OVEN 
THERMAL
CUT-OUT
BLOWER
MOTOR 
THERMAL
CUT-OUT
SECONDARY
INTERLOCK
SWITCH (1)
MAGNETRON
THERMAL
CUT-OUT (1)
(UPPER)
PRIMARY
INTERLOCK
RELAY (2)
B3
OVEN THERMISTOR
D1D3
TAB2 TAB1
PRIMARY
INTERLOCK
RELAY (1)
MAGNETRON
THERMAL
CUT-OUT (2)
(LOWER)
YLW
BLK
MONITOR SWITCH (1) MONITOR SWITCH (2)
WHT/GRY GRY
YLW BLK
POWER
TRANSFORMER (1) 
(FRONT)
CAPACITOR (1)
0.75µF
CAPACITOR (2)
0.75µF
POWER
TRANSFORMER (2) 
(REAR)
RECTIFIER (1) 
RECTIFIER (2) 
BLK
ORG
MAGNETRON (2) (LOWER)
GRN
RY1
SECONDARY
INTERLOCK
SWITCH (2)

9
R-22GV
R-22GT
R-23GT
R-24GT
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. SELECTATIME PAD TOUCHED.
3. COOKING TIME PROGRAMMED.
4. START PAD TOUCHED.
Figure O-3. R-23GT/24GT Oven SChematic-Cooking Condition (208 VCondition)
FUSE 20A
OVEN LAMP
BLOWER MOTOR
208/230V 60Hz
MAGNETRON (1) (UPPER)
BM
STIRRER MOTOR
SM SM
OL
H3 H1
MAGNETRON THERMISTOR
INTAKE  THERMISTOR
BLKWHT
DOOR SENSING
SWITCH
A1 A3 B2 B1
A7
RY2 RY3
OVEN 
THERMAL
CUT-OUT
BLOWER
MOTOR 
THERMAL
CUT-OUT
MAGNETRON
THERMAL
CUT-OUT (1)
(UPPER)
PRIMARY
INTERLOCK
RELAY (2)
B3
OVEN THERMISTOR
D1D3
TAB2 TAB1
PRIMARY
INTERLOCK
RELAY (1)
MAGNETRON
THERMAL
CUT-OUT (2)
(LOWER)
RED
PNK
MONITOR SWITCH (2) MONITOR SWITCH (1)
GRY
WHT
PNK RED
POWER
TRANSFORMER (1) 
(FRONT)
CAPACITOR (1)
0.94µF
CAPACITOR (2)
0.94µF
POWER
TRANSFORMER (2) 
(REAR)
RECTIFIER (1) 
RECTIFIER (2) 
MAGNETRON (2) (LOWER)
RY1
A5
WHT/GRY
OL
VOLTAGE SELECT SWITCH (V.S.SW) (2)
COM
NC
COM
NC
V.S.SW (1)
COM
NC
NC
COM
V.S.SW (4)
V.S.SW (3)
SECONDARY
INTERLOCK
SWITCH (1)
SECONDARY
INTERLOCK
SWITCH (2)
BLK RED
Figure O-3. R-22GV/22GT Oven SChematic-Cooking Condition
FUSE 20A
OVEN LAMP
BLOWER MOTOR
120V 60Hz
MAGNETRON (1) (UPPER)
BM
STIRRER MOTOR STIRRER MOTOR
SM SM
OL
H3 H1
MAGNETRON THERMISTOR
INTAKE  THERMISTOR
BLK
WHT
GRY
GRY
DOOR SENSING
SWITCH
A1 A3 B2 B1
A7
RY2 RY3
OVEN 
THERMAL
CUT-OUT
BLOWER
MOTOR 
THERMAL
CUT-OUT
SECONDARY
INTERLOCK
SWITCH (1)
MAGNETRON
THERMAL
CUT-OUT (1)
(UPPER)
PRIMARY
INTERLOCK
RELAY (2)
B3
OVEN THERMISTOR
D1D3
TAB2 TAB1
PRIMARY
INTERLOCK
RELAY (1)
MAGNETRON
THERMAL
CUT-OUT (2)
(LOWER)
YLW
BLK
MONITOR SWITCH (1) MONITOR SWITCH (2)
WHT/GRY GRY
YLW BLK
POWER
TRANSFORMER (1) 
(FRONT)
CAPACITOR (1)
0.75µF
CAPACITOR (2)
0.75µF
POWER
TRANSFORMER (2) 
(REAR)
RECTIFIER (1) 
RECTIFIER (2) 
BLK
ORG
MAGNETRON (2) (LOWER)
GRN
RY1
SECONDARY
INTERLOCK
SWITCH (2)

10
R-22GV
R-22GT
R-23GT
R-24GT
DOOR OPEN MECHANISM
1. The door release lever is pulled.
2. The upper latch head is lifted up by the linked door
release lever.
3. The latch lever is lifted up by the door release lever.
4. The joint lever is lifted up by the latch lever.
5. The lower latch head is lifted up by the joint lever.
6. Now both latch heads are lifted up, so they can be
released from the latch hook.
7. Now the door can be opened.
Latch head
Monitor switch (1)
Latch hook
Secondary interlock 
switch (1)
Door sensing switch
Latch head
Joint lever
Door release
lever
Latch lever
Secondary interlock 
switch (2)
Monitor switch (2)
Switch lever C
Switch lever A
Switch lever B
Figure D-1. Door Open Mechanism
DOOR SENSING SWITCH
Thedoorsensingswitchisactivatedbythelatchheadofthe
door and switch lever C. When the door is opened, the
contacts of the switch open and interrupt the circuit to the
coils of the primary interlock relay (1), (2). The contacts of
the primary relay (1), (2) then open and interrupt the circuit
to the primary winding of the power transformers. At this
time, the contacts of relay RY1 close and the blower motor,
stirrer motors and oven lamps are energized for 1 minute.
SECONDARY INTERLOCK SWITCHES (1), (2)
The secondary interlock switch (1), (2) are activated by the
upper latch head of the door and switch lever B. When the
doorisopened,thecontactsoftheswitchopenandinterrupt
the circuit to the primary winding of the power transformers
(1), (2).
MONITOR SWITCHES (1), (2)
The monitor switches (1), (2) are mounted in the upper
position of the latch hook. The monitor switches are acti-
vated by the upper latch head of the door and switch lever
A. When the door is opened, the contacts of the monitor
switches close. Monitor switch (1) is intended to render the
oven inoperative by means of blowing the monitor fuse,
when the contacts of the primary interlock relay (1) and
secondary interlock switch (1) fail to open when the door is
opened. Monitor switch (2) is intended to render the oven
inoperativebymeansofblowingthemonitorfuse,whenthe
contacts of the primary interlock relay (2) and secondary
interlock switch (2) fail to open when the door is opened.
Functions:
With the door shut, the contacts of the door sensing switch
andthesecondaryinterlockswitches(1),(2)areclosedand
the contacts of the monitor switches (1), (2) are open.
1. Whenthedoorisopened,thecontactofthedoorsensing
switch and secondary interlock switches (1), (2) are
openedfirst,thenthecontactofthemonitorswitches(1),
(2) are closed.
2. Asthedoorgoestoaclosedposition,thecontactsofthe
monitor switches (1), (2) are opened first, then the
contacts of the door sensing switch and the secondary
interlock switches (1), (2) close.
3. If the door is opened, and the contacts of the primary
interlock relay and secondary interlock switch of the
same circuit fail to open, the monitor fuse blows
simultaneouslywithclosingofthemonitorswitchcontacts
of that circuit (1 or 2).
CAUTION: BEFORE REPLACING A BLOWN MONITOR
FUSE TEST THE DOOR SENSING SWITCH,
PRIMARYINTERLOCKRELAYS(1),(2),SEC-
ONDARYINTERLOCKSWITCHES(1),(2)AND
MONITOR SWITCHES (1), (2) FOR PROPER
OPERATION. (REFER TO CHAPTER "TEST
PROCEDURE").
NOTE: MONITORFUSEANDSWITCHAREREPLACED
AS AN ASSEMBLY.
MAGNETRON THERMAL CUT-OUTS (1), (2)
Thethermal cut-outs (1),(2) locatedon thetop ofthe upper
and lower waveguide, are designed to prevent damage to
the magnetrons (1), (2). If an over heated condition devel-
ops in the tube due to blower motor failure, obstructed air
ducts, dirty or blocked air intake, etc., the circuit to the
magnetrons are interrupted. Under normal operation, the
thermal cut-outs remains closed. However, when abnor-
mallyhightemperaturesaregeneratedwithinthemagnetron,
the thermal cut-out will open at 293˚F (145˚C) causing the
microwave energy to stop. The defective thermal cut-out
must be replaced with new rated one.
OVEN THERMAL CUT-OUT
Thethermalcut-out, locatedon thesideofthe exhaustduct
assembly, is designed to prevent damage to the oven by
fire. If the food 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 tempera-
turesaregeneratedwithintheovencavity,theoventhermal
cut-outwill openat239˚F (115˚C),causing theoven toshut
down. The defective thermal cut-out must be replaced with
new rated one.
OVEN THERMISTOR
The thermistor is a negative temperature coefficient type.
Thetemperatureintheexhaustductisdetectedthroughthe
resistance of the thermistor.
Ifthetemperatureishigh,thecontrolpanelwilldisplay“EE7”
andtheovenwillstoptoavoidoverheatingandcatchingfire.
Ifthethermistor isopen,thecontrol panelwilldisplay "EE6"
and the oven will stop.
DESCRIPTION AND FUNCTION OF COMPONENTS

11
R-22GV
R-22GT
R-23GT
R-24GT
OVEN LAMPS
The oven cavity light illuminates the interior of the oven so
that food being cooked can be examined visually through
thedoor windowwithout havingto openthe door.The oven
lamp is on during the cooking cycle and idle condition.
SELECT SWITCHES (1) - (4) (for R-23GT and R-
24GT)
The select switch assembly is an array of four separate
switches which may be configured for either 208V or 230V
operation(seeGeneralInformationsection,voltageselect).
These switches are connected to the windings of compo-
nents specified in the table below and make those compo-
nentscompatiblewiththespecifiedlinevoltagebychanging
their internal windings. For 208V operation contacts (Nor-
mal Open) of the all switches are open.
SELECT SWITCH (1)
COM.
SELECT
SWITCH (2)
N.C. N.O SELECT SWITCH ANGLE
SELECT SWITCH (3)
SCREW
SELECT SWITCH (4)
Oven
cavity
Rear
cabinet
side
SELECT SWITCH AND ELECTRICAL COMPONENTS
CONDITION
SWITCH NO. ELECTRICAL PARTS
(1) Touch control unit
(2) Blower motor
(3) Power transformer (1) (Front side)
(4) Power transformer (2) (Rear side)
Oven in the 208V setting: contacts between common and
normally open are closed.
Oven in the 230V setting: contacts between common and
normally closed are closed.
INTAKE THERMISTOR
This thermistor detects ambient air temperature. The ther-
mistor is a negative temperature coefficient type. The tem-
perature around the lower position of control panel is de-
tected through the resistance of the thermistor.
Ifthethermistorremainsinashortedconditionformorethan
2 minutes, the control will display “EE10” and stop operat-
ing.
MAGNETRON THERMISTOR
The thermistor is a negative temperature coefficient type.
The air temperature around the lower magnetron is de-
tected through the resistance of the thermistor.
If the temperature is high, the control panel will display
"EE17"andtheovenwillstoptoprotectthelowermagnetron
against overheat.
Ifthethermistorisopen,thecontrolpanelwilldisplay"EE16"
and the oven will stop.
BLOWER MOTOR THERMAL CUT-OUT 115˚C
This thermal cut-out protects the blower motor against
overheating. If its temperature goes above 239˚F (115˚C)
because the blower motor is stalled or the ventilation open-
ings are blocked, the contacts of the thermal cut-out will
open. The line voltage to the control unit will be cut off and
the operation of the oven will be stopped. The defective
thermal cut-out must be replaced with a new one.
BLOWER MOTOR
The blower motor drives a blade which draws external cool
air into the oven. This cool air is directed through the air
vanes surrounding the magnetrons and cools the
magnetrons. This air is channelled through the oven cavity
to remove steam and vapours given off from the heating
foods.It isthen exhaustedthrough theexhaustingair vents
at the oven cavity.
STIRRER MOTOR
The upper and lower stirrer motors drive stirrer antennas to
stir the microwave radiation from the upper and lower
waveguides.
TROUBLESHOOTING GUIDE
Whentroubleshootingthe microwave oven,it ishelpful to followthe Sequence ofOperation inperforming the checks.Many ofthe
possiblecausesoftroublewillrequirethataspecifictestbeperformed.Thesetestsaregivenaprocedureletterwhichwillbefound
in the "Test Procedure"section.
IMPORTANT: If the oven becomes inoperative because of a blown monitor fuse, check the monitor switches (1), (2),
primary interlock relays (1), (2), door sensing switch and secondary interlock switches (1), (2) before
replacing the monitor fuse. If monitor fuse is replaced, the mintor switches (1) and/or (2) must also be
replaced. Use part FFS-MA012WRK0 (R-22GV/22GT)/ FFS-MA015WRK0 (R-23GV/24GT) as an assem-
bly.

12
R-22GV
R-22GT
R-23GT
R-24GT
Homefuseblowswhenpowercordisplugged
into wall receptacle
Monitor fuse blows when power cord is
plugged into wall receptacle.
" . " does not appear in display when power
cord is first plugged into wall receptacle.
Blowermotordoesnotoperate.(Ovenlamp(s)
and stirrer motors go on for 1 minute after
door is opened.)
Blower motor, oven lamp(s) and stirrer mo-
tors do not go on for 1 minute after door is
opened.
Blower motor and stirrer motors go on but
oven lamp(s) do not light for 1 minute after
door is opened.
Blower motor, oven lamp(s) and stirrer mo-
tors keep going on after more than 1 minute
when door is opened and closed.
Blower motor, oven lamp(s) and stirrer mo-
tors do not go on in cook cycle.
Oven goes into a cook cycle but shuts down
before and off cooking cycle.
Oven does not go into cook cycle when
START pad is touched.
Lowor no power isproduced during cooking
condition. (The food is heated incompletely
or not heated at all.)
Extremely uneven heating is produced in
oven load (food).
Variable cooking does not operates prop-
erly, except HIGH power functions.
"EE1" Magnetron (1) failure.
"EE2" Magnetron (2) failure.
"EE3" Magnetron (1) and (2) failure.
"EE4"Voltageistoohigh(forR-23GT/24GT).
"EE5"Voltageistoolow(forR-23GT/24GT).
"EE6" Thermistor failure.
"EE7" Exhaust air temperature is too high.
"EE8" Relay melt short.
"EE9" Maximum time is exceeded.
"EE0" Fan lock judge.
"EE10" Intake thermistor is shorted.
"EE16" Magnetron thermistor is open.
"EE17" Magnetron temperature is too high.
CK = Check / RE = Replace/ RST= Reset
PROBLEM
CONDITION
TEST PROCEDURE ABCDEFFGIJJCKCKHHHH
OFF
CONDITION
COOKING
CONDITION
ERROR
MODE
(2) (2) (2) (2) (2) (2)
(1) (1) (1) (1) (1) (1)

13
R-22GV
R-22GT
R-23GT
R-24GT
J K K K L M N N N O CKCK CK CK CK RSTRST CK CK

14
R-22GV
R-22GT
R-23GT
R-24GT TEST PROCEDURES
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.
Totestforanopenfilament,isolatethemagnetronfromthehighvoltagecircuit.Acontinuitycheckacross
the magnetron filament leads should indicate less than 1 ohm.
Totestforashortedmagnetron,connecttheohmmeterleadsbetweenthemagnetronfilamentleadsand
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
shouldonlybeusedifabovetestsdonotindicateafaultymagnetronandthereisnodefectinthefollowing
componentsorwiring:siliconrectifier,highvoltagecapacitorandpowertransformer.Thistestwillrequire
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. Fillthemeasuringcupwith16oz.(453cc)oftapwaterandmeasurethetemperatureofthewaterwith
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. Placethe cup ofwater inthe oven.Operate ovenat 100% POWERselecting morethan 60seconds
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. Refer to the chart below for the
normal temperature rise of each model. 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
temperaturerisetestindicatesapoweroutputwellbeyondthenormallimits.Thetestisonlyaccurate
ifthepowersupplylinevoltageis208/230 voltsformodelsR-23GT,R24GT and120voltsformodels
R-22GV, R-22GT and the oven cavity is clean.
Model RF output Normal temperature rise Line voltage
R-22GV/22GT 1200W 36.5 - 67.9˚F (20.3 - 37.7˚C) 120V
R-23GT 1600W 46.6 - 86.6˚F (25.9 - 48.1˚C) 208V/230V
R-24GT 1800W 50.4 - 93.6˚F (28.0 - 52.0˚C) 208V/230V
PROCEDURE
LETTER COMPONENT TEST
A MAGNETRON ASSEMBLY TEST
B POWER TRANSFORMER TEST
DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS
OR WIRING.
Disconnecttheprimaryinputterminalsandthesecondaryoutputterminals,andmeasuretheresistance
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 filament coil should be approximately and the resistance of the high voltage
coil and primary coil should be as follows:
Model Primary coil High voltage coil Part code
R-22GV/22GT Approx. 0.42 ΩApprox. 106 ΩRTRN-A453WRE0
Approx. 0.86 Ω(at 208V) Approx. 65 ΩRTRN-A454WRE0
R-23GT Approx. 0.95 Ω(at 230V)
Approx. 0.86 Ω(at 208V) Approx. 60 ΩRTRN-A455WRE0
R-24GT Approx. 0.95 Ω(at 230V)

15
R-22GV
R-22GT
R-23GT
R-24GT
PROCEDURE
LETTER COMPONENT TEST
TEST PROCEDURES (CONT'D)
(HIGHVOLTAGESARE PRESENTATTHE HIGHVOLTAGE TERMINAL,SODO NOTATTEMPT TO
MEASURE THE VOLTAGE OF THE FILAMENT AND HIGH VOLTAGE COILS.)
C HIGH VOLTAGE RECTIFIER (1) AND/OR (2) TEST
DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS
OR WIRING.
Isolatetherectifierfromthecircuit. Usingthehighestohm scaleofthemeter, readtheresistanceacross
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: Besuretouseanohm-meterthatwillsupplyaforwardbiasvoltageofmorethan6.3volts.
DHIGH VOLTAGE CAPACITOR (1) AND/OR (2) 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.
Checkingwith ahigh ohmscale, ifthe highvoltagecapacitor isnormal, themeterwill indicatecontinuity
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.
Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal
ofthe switch.The metershouldindicated anopencircuit withthedoor openanda closedcircuitwith the
door closed. If improper operation is indicated, replace the secondary interlock switch.
F PRIMARY INTERLOCK SYSTEM TEST
DOOR SENSING SWITCH
Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal
ofthe switch.The metershouldindicated anopencircuit withthedoor openanda closedcircuitwith 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 blower
motor, stirrer motors and oven light will be activated by RY1 for one minute.
PRIMARY INTERLOCK RELAY (1), (2)
Disconnect two (2) wire leads from the male tab terminal of the Primary Interlock Relay (1) and (2).
Primary Interlock Relay (1) RY-2
Primary Interlock Relay (2) RY-3
Check the state of the relay contacts via tab terminal using a ohmmeter. The relay contacts should be
open. If the relay contacts are closed, replace the circuit board entirely or the relay itself.
E SECONDARY INTERLOCK SWITCH TEST
G MONITOR SWITCHES (1), (2) TEST
Disconnect the oven from power supply. Before performing this test, make sure that the secondary
interlock switches (1), (2) and the primary interlock relays (1), (2) are operating properly, according to
the above Switch Test Procedure.
Disconnectthewireleadfromterminal(COM.)ofthemonitorswitch(es)(1)and/or(2).Checkthemonitor
switch(es) (1) and/or (2) operation using the an ohmmeter. Connect ohmmeter leads between monitor
switch (COM.) terminal and (N.C.) terminal. 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 upper latch hole on
thefront plateof theovencavity withthedoor opened(in thisconditionthe plungerofthe monitorswitch
ispushedin),themetershouldindicateanopencircuit.Ifimproperoperationisindicated,theswitchmay
be defective. After testing the monitor switch, re-connect the wire lead to the monitor switch (COM.)
terminal and check the continuity of the monitor circuit.

16
R-22GV
R-22GT
R-23GT
R-24GT TEST PROCEDURES (CONT'D)
COMPONENT TEST
PROCEDURE
LETTER
SCREW DRIVER
MONITOR SWITCH (2)
OHMMETER
MONITOR SWITCH (1)
LATCH HOOK
Magnetron (1) Failure:
Test magnetron (1) and Blower fan motor.
Magnetron (1), (2) Failure: Test magnetron (1), (2).
Check blower fan motor and ventilation opening.
Magnetron (2) Failure:
Test magnetron (2) and Blower fan motor.
Check blower fan motor and ventilation opening or
rocked rotating of blower fan motor.
Food has been burned in oven.
Temperature of oven inside is very high.
A continuity check across the thermal cut-out terminals should indicate a closed circuit unless the
temperature of the thermal cut-out reaches specified temperature. The thermal cut-out reset automati-
cally at specific temperature.
Open Close Display or
temperature temperature Condition Check point
Blower motor ther-
mal cut-out
Oven thermal cut-
out
Magnetron thermal
cut-out (2)
Magnetron thermal
cut-out (1)
145˚C
115˚C
115˚C
Non resetable
type
EE1
EE3
EE2
Oven shut
off
Oven shut
off
Non resetable
type
Non resetable
type
H SELECT SWITCHES (1) (4) TEST (FOR R-23GT, R-24GT)
Isolate switch and check the contacts by using an ohmmeter with following table. If improper operation
is indicated, make the necessary switch adjustment or replacement.
Table: Switch Connection
Plunger operation Between COM. and NO. Between COM. and NC. COM.: Common terminal
Plunger released Open circuit Close circuit NO.: Normal Open terminal
Plunger operation Close circuit Open circuit NC.: Normal Close terminal
SELECT SWITCH (1)
COM.
SELECT
SWITCH (2)
N.C. N.O SELECT SWITCH ANGLE
SELECT SWITCH (3)
SCREW
SELECT SWITCH (4)
Oven
cavity
Rear
cabinet
side
IBLOWN MONITOR FUSE
Ifthemonitorfuseisblownwhenthedoorisopened,checktheprimaryinterlockrelay(1),(2),secondary
interlock switches (1), (2), door sensing switch and monitor switches (1), (2) 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
RELAYS,SECONDARYINTERLOCKSWITCHES,DOORSENSINGSWITCHANDMONI-
TOR SWITCHES FOR PROPER OPERATION.
Ifthe monitorfuse isblown byimproperswitch operation,themonitor fuseandswitch mustbe replaced
with "monitor fuse and switch assembly" part number FFS-BA012WRK0 (for R-22GV/GT) or FFS-
BA015WRK0 (for R-23GT/24GT), even if the monitor switch operates normally. The monitor fuse and
switch assembly is comprised of a 20 ampere fuse and switch.
JTHERMAL CUT-OUTS

17
R-22GV
R-22GT
R-23GT
R-24GT
TEST PROCEDURES (CONT'D)
PROCEDURE
LETTER COMPONENT TEST
When replacing thermal cut-out, check plastic contents around thermal cut-out. If they are damaged,
replace them with each defective thermal cut-out.
CAUTION: IFTHETHERMALCUT-OUTINDICATESANOPENCIRCUITATROOMTEMPERATURE,
REPLACE THE THERMAL CUT-OUT.
K MAGNETRON THERMISTOR TEST
Disconnectconnector-HfromtheCPUunit.Measuretheresistanceofthethermistorwithanohmmeter.
Connect the ohmmeter leads to the leads of the thermistor.
Room Temp. 59˚F (15˚C) 68˚F (20˚C) 77˚F (25˚C)
Resistance Approx. 15.91 kΩApprox. 13.04 kΩApprox. 10.74 kΩ
If the meter does not indicate above resistance, replace the thermistor.
OVEN THERMISTOR TEST
Disconnectconnector-BfromtheCPUunit.Measuretheresistanceofthethermistorwithanohmmeter.
Connect the ohmmeter leads to the leads of the thermistor.
Room Temp. 59˚F (15˚C) 68˚F (20˚C) 77˚F (25˚C)
Resistance Approx. 77.45 kΩApprox. 61.47 kΩApprox. 49.12 kΩ
If the meter does not indicate above resistance, replace the thermistor.
INTAKE THERMISTOR TEST
Disconnectconnector-DfromtheCPUunit.Measuretheresistanceofthethermistorwithanohmmeter.
Connect the ohmmeter leads to the leads of the thermistor.
Room Temp. 59˚F (15˚C) 68˚F (20˚C) 77˚F (25˚C)
Resistance Approx. 15.88 kΩApprox. 13.03 kΩApprox. 10.74 kΩ
If the meter does not indicate above resistance, replace the thermistor.
L TOUCH CONTROL PANEL ASSEMBLY TEST
The touch control panel consists of circuits including semiconductors such as LSI, IC, etc. Therefore, unlike
conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter and
ohmmeter.Inthisservicemanual,thetouchcontrolpanelassembly is divided into two units, Control Unitand
Key Unit, troubleshooting by unit replacement is described according to the symptoms indicated.
1. Key Unit
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 the pads, sometimes a pad produces no signal.
2. Control Unit
The following symptoms may indicate a defective control unit. Replace the control unit.
2-1 Programming problems.
a) When touching the pads, a certain group of pads do not produce a signal.
2-2 Display problems.
a) For a certain digit, all or some segments do not light up.
b) For 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) Cooking is not possible.
Note: When defective components, (the Control Unit or Key Unit) are replaed, the defective part or parts
must be properly packed for return in the shipping carton. with its cushion material, in which the new
replacement part was shipped to you.

18
R-22GV
R-22GT
R-23GT
R-24GT TEST PROCEDURES (CONT'D)
PROCEDURE
LETTER COMPONENT TEST
M KEY UNIT TEST
Ifthedisplay fails toclear whenthe STOP/CLEAR padis depressed, firstverify theflat ribbon ismaking 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 stop switch connector ). Use the key unit matrix indicated
onthecontrolpanelschematicandplaceajumperwirebetweenthepinsthatcorrespondtotheSTOP/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 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.
1
3
4
5
6
7
8
9
0
G 8
G 7G 6G 5G 4
G 3
G 2
G 1
G 9
G 10
G 11
G 12
2
DOUBLE
QUANTITY
EXPRESS
DEFROST
SELECTA
TIME
STOP /
CLEAR
START SET
CHECK
SIGNAL
1
3
4
5
6
7
8
9
0
G 8
G 7G 6G 5G 4
G 3
G 2
G 1
G 9
G 10
G 11
G 12
2
DOUBLE
QUANTITY
EXPRESS
DEFROST
SELECTA
TIME STOP /
CLEAR
START SET
CHECK
SIGNAL
SELECTA
POWER
R-22GV R-22GT/R-23GT/R-24GT
N RELAY TEST
Remove the outer case and check voltage between Pin Nos. 3 and 7 of the connector (A) on the control unit
with an A.C. voltmeter. The meter should indicate rated voltage, if not, check oven circuit.
RY1, RY2 and RY3Relay 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 unit is defective.
RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS
RY1 APPROX. 12.0V D.C. Oven lamps, Blower motor and Stirrer motors
RY2 APPROX. 12.0V D.C. Power transformer 1
RY3 APPROX. 12.0V D.C. Power transformer 2
O PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD
(PWB) IS OPEN
Toprotecttheelectroniccircuits,thismodelisprovidedwithafinefoilpatternaddedtotheprimaryonthePWB,
thisfoilpatternactsasafuse.Ifthefoilpatternisopen,followthetroubleshootingguidegivenbelowforrepair.
Problem: POWER ON, indicator does not light up.
STEPS OCCURANCE CAUSE OR CORRECTION
1 The rated voltage is not applied to POWER Check supply voltage and oven power cord.
terminal of CPU connector (CN-A)
2 The rated voltage is applied to primary side Power transformer or secondary circuit defective.
of power 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