Sharp R530es Service Manual

							R530EWT
6 – 3 2. Cooking Condition
                                                                            Figure O-2. Oven Schematic-Cooking Condition
[3] DESCRIPTION AND FUNCTION OF COMPONENTS
1. 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 but-
ton pushes up the switch lever, and then the switch lever pushes up
the latch head. The latch heads are moved upward and released from
latch hook. Now the door will open.
                                   Figure D-1. Door Open Mechanism.
2. DOOR SENSING AND SECONDARY INTERLOCK
SWITCHES
The secondary interlock switch is mounted in the lower position of the
latch hook and the door sensing switch in the secondary interlock sys-
tem is mounted in the upper position of the latch hook. They are acti-
vated by the latch heads on the door. When the door is opened, the
switches interrupt the power to all high voltage components. A cook cycle cannot take place until the door is firmly closed there by
activating both interlock switches. The primary interlock system con-
sists of the door sensing switch and primary interlock relay located on
the control circuit board. 
3. 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 blowing the monitor fuse,
when the contacts of the primary interlock relay (RY2) and secondary
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 relay (RY2) and secondary interlock switch are in
the OFF condition (contacts open) due to their 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 and the second-
ary interlock switch contacts close. (On opening the door, each of
these switches operate inversely.)
3) If the door is opened, and the primary interlock relay (RY2) and
secondary 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 DOOR SENSING SWITCH, PRIMARY INTERLOCK
RELAY (RY2), RELAY (RY1), SECONDARY INTERLOCK
SWITCH AND MONITOR SWITCH FOR PROPER OPER-
ATION. (REFER TO CHAPTER “TEST PROCEDURE”).
NOTE:MONITOR FUSE AND MONITOR SWITCH ARE REPLACED
AS AN ASSEMBLY. SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME PROGRAMMED.
3. VARIABLE COOKING CONTROL P-HI/ 100 PERCENT.
4. START PAD TOUCHED.
C3 C2
C1
NOISE
FILTER
MONITOR
FUSE (20A) R2
120V
AC60 Hz
FAN
MOTORMONITOR
SWITCH
H.V. RECTIFIER
MAGNETRON
TTM
OL FMCAVITY
TEMP.
FUSE
MAGNETRON
TEMP. FUSE
A1 A2
COM. COM. N.O.
N.C.
DOOR
SENSING
SWITCH (RY-1)(RY-2)
PRIMARY
INTERLOCK
RELAY
CONTROL UNIT
B1 B2 GRN
POWER
TRANSFORMERCAPACITOR
1.0mF AC 2300V
F3
F1F2
AH SENSOR
SECONDARY
INTERLOCKS
WITCH OVEN
LAMPTURN-
TABLE
MOTOR
Door Sensing
Switch
Monitor Switch
Switch Lever
Secondary Interlock
Switch
Latch Heads
Door 
						

							R530EWT
6 – 4 4. 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.
5. 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 magne-
tron and cools the magnetron. This air is channeled through the oven
cavity to remove steam and vapors given off from the heating foods. It
is then exhausted through the exhausting air vents at the oven cavity.
6. CAVITY TEMPERATURE FUSE 
The cavity temperature fuse located on the top of the oven cavity, 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 cavity temperature fuse will open. 
Under normal operation, the cavity temperature fuse remains closed.
However, when abnormally high temperatures are reached within the
oven cavity, the cavity temperature fuse will open at 302°F(150°C)
causing the oven to shut down.
NOTE: This is a fuse. It does not reset.
7. MAGNETRON TEMPERATURE FUSE
The magnetron temperature fuse located near the magnetron is
designed to prevent damage to the magnetron if an over heated condi-
tion develops in the tube due to cooling fan failure, obstructed air
guide, dirty or blocked air intake, etc. 
Under normal operation, the magnetron temperature fuse remains
closed. However, when abnormally high temperatures are reached
within the magnetron, the magnetron temperature fuse will open at
302°F(150°C) causing the oven to shut down.
NOTE: This is a fuse. It does not reset.
8. MONITOR FUSE
1) The monitor fuse blows when the contacts (COM-NO) of the pri-
mary interlock relay (RY2) and secondary interlock switch remain
closed with the oven door open and when the monitor switch
closes.
2) If the wire harness or electrical components are short-circuited, this
monitor fuse blows to prevent an electric shock or fire hazard.
9. NOISE FILER
The noise filter prevents the radio frequency interference that might
flow back in the power circuit.  
						

							R530EWT
7 – 1
R530EWTService Manual CHAPTER 7. 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,
check the monitor switch, relay (RY1), primary interlock relay (RY2),
door sensing switch and secondary interlock switch before replacing
the monitor fuse. If the monitor fuse is replaced, the monitor switch
must also be replaced. Use part FFS-BA033WRKZ or FFS-
BA037WRKZ as an assembly.
IMPORTANT:
Whenever troubleshooting is performed with the power supply cord
disconnected. It may in, some cases, be necessary to connect the
power supply cord after the outer case has been removed, in this
event,
1) Disconnect the power supply cord, and then remove outer case.
2) Open the door and block it open.3) Discharge high voltage capacitor.
4) Disconnect the leads to the primary of the power transformer.
5) Ensure that the leads remain isolated from other components and
oven chassis by using insulation tape.
6) After that procedure, reconnect the power supply cord.
When the testing is completed,
1) Disconnect the power supply cord, and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Reconnect the leads to the primary of the power transformer.
5) Reinstall the outer case (cabinet).
6) Reconnect the power supply cord after the outer case is installed.
7) Run the oven and check all functions.    Never touch any part in the circuit with your hand or an uninsulated tool while the power supply is connected.
RE CK A B C D E F F G H RE RE CK J CK CK CK K L N OI
POSSIBLE CASE
AND DEFECTIVE PARTS
SHORT IN POWER CORD
SHORT OR OPENED WIRING
MAGNETRON
POWER TRANSFORMER
H.V. RECTIFIER ASSEMBLY
HIGH VOLTAGE CAPACITORMAGNETRON TEMPERATURE FUSEPRIMARY INTERLOCK SYSTEM
SECONDARY INTERLOCK SWITCHMONITOR SWITCH
MONITOR FUSE
OVEN LAMP
COOLING FAN MOTOR
TURNTABLE MOTOR
TOUCH CONTROL PANEL
WRONG OPERATION
LOW VOLTAGE
DIRTY OVEN CAVITY
KEY UNIT
RELAY (RY1)
FOIL PATTERN ON PWB
AH SENSOR NOISE FILTERCONDITIONPROBLEM
OFF
CONDITION
TTEST PROCEDURE
COOKING
CONDITION
SENSOR
COOKING
CONDITIONE
CAVITY
TEMPERATURE FUSE
M
DEFROST CENTER
Home fuse or circuit breaker blows when
power cord is plugged into wall receptacle
Monitor fuse blows when power cord is plug-
ged into wall receptacle.
All letters and indicators do not appear in dis-
play when power cord is first plugged into
wall outlet.
Display does not operate properly when
STOP/CLEAR pad 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 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 incom-
pletely 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 program-
med for Cooking Power 50 PERCENT mode.
(Operates properly on Cooking Power 100
PERCENT mode.)
Oven goes into DEFROST but food is not
defrosted well.
AH sensor does not end during Sensor cook-
ing condition. (Oven does not shut off after a
cup of water is boiling by sensor cooking.)
Oven stops at 16 sec. after starting. 
						

							R530EWT
8 – 1
R530EWTService Manual CHAPTER 8. TEST PROCEDURES
[1] A: MAGNETRON ASSEMBLY TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. 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.
5. 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.
6. Reconnect all leads removed from components during testing.
7. Reinstall the outer case (cabinet).
8. Reconnect the power supply cord after the outer case is installed.
9. Run the oven and check all functions.
1. MICROWAVE OUTPUT POWER
The following test procedure should be carried out with the microwave oven in a fully assembled condition (outer case fitted).
HIGH VOLTAGES ARE PRESENT DURING THE COOK CYCLE, SO EXTREME CAUTION SHOULD BE OBSERVED.
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 indi-
cate 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 tempera-
ture 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 100% PERCENT POWER 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 33 to 62°F(18.6 to 34.5°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 volt-
age is 120 volts and the oven cavity is clean.
[2] B: POWER TRANSFORMER TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. 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 105 ohms; the resistance of the filament coil should be less than 1 ohm.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
(HIGH VOLTAGES ARE PRESENT AT THE HIGH VOLTAGE TERMINAL, SO DO NOT ATTEMPT TO MEASURE THE FILAMENT AND HIGH
VOLTAGE.)
[3] C: HIGH VOLTAGE RECTIFIER TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. 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 direc-
tions, the rectifier is probably defective and should be replaced.
5. Reconnect all leads removed from components during testing. 
						

							R530EWT
8 – 2
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
NOTE: Be sure to use an ohmmeter that will supply a forward bias voltage of more than 6.3 volts.
[4] D: HIGH VOLTAGE CAPACITOR TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. 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 termi-
nals 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.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
[5] E: TEMPERATURE FUSE OR THERMAL CUT-OUT TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Check a continuity across the temperature fuse or thermal cut-out terminals in the table below. 
5. An open temperature fuse or thermal cut-out (Magnetron) indicates overheating of the magnetron. Check for restricted air flow to the magnetron,
especially the cooling fan and air guide.
An open temperature fuse or thermal cut-out (Cavity) indicates overheating of the oven, exchange the temperature fuse or 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.
6. Reconnect all leads removed from components during testing.
7. Reinstall the outer case (Cabinet).
8. Reconnect the power supply cord after the outer case is installed.
9. Run the oven and check all functions.
CAUTION: IF THE TEMPERATURE FUSE OR THERMAL CUT-OUT INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE, REPLACE IT.
[6] F: SECONDARY INTERLOCK SWITCH AND PRIMARY INTERLOCK SYSTEM TEST
1. SECONDARY INTERLOCK SWITCH
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal of the switch. The meter should indicate an
open circuit with the door open and a closed circuit with the door closed. If improper operation is indicated, replace the secondary interlock switch.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.Table: Temperature Fuse and Thermal Cut-out Test
Parts NameTemperature of “ON” condition 
(closed circuit).Temperature of “OFF” condition 
(open circuit).Indication of ohmmeter (When room 
temperature is approx. 20°C.)
Temperature fuse 150°C This is not resetable type. Above 150°C (302°F) Closed circuit
Thermal cut-out 145°C This is not resetable type. Above 145°C (293°F) Closed circuit 
						

							R530EWT
8 – 3 2. PRIMARY INTERLOCK SYSTEM
2.1. DOOR SENSING SWITCH
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal of the switch. The meter should indicate 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.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
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.
2.2. PRIMARY INTERLOCK RELAY (RY2)
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect two (2) wire leads from the male tab terminals of the Primary 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.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
[7] G: MONITOR SWITCH TEST
1. Disconnect the power supply cord, and then remove outer
case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Before performing this test, make sure that the secondary
interlock switch and the primary interlock relay are operat-
ing properly, according to the above Switch Test Proce-
dure. 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, reconnect the wire lead to the monitor switch
(COM) terminal and check the continuity of the monitor circuit.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
[8] H: BLOWN MONITOR FUSE TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. If the monitor fuse is blown when the door is opened, check the secondary interlock switch, primary interlock relay (RY2), relay (RY1) 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 SECONDARY INTERLOCK SWITCH, PRIMARY INTERLOCK RELAY,
DOOR SENSING SWITCH AND MONITOR SWITCH FOR PROPER OPERATION. 
If the monitor fuse is blown by improper switch operation, the monitor fuse and monitor switch must be replaced with “monitor fuse and monitor
switch assembly” part number FFS-BA033WRKZ or FFS-BA037WRKZ, even if the monitor switch operates normally. The monitor fuse and moni-
tor switch assembly is comprised of a 20 ampere fuse and switch.
5. Reconnect all leads removed from components during testing.
Secondary
Interlock Switch
Monitor Switch
Screw Driver
Ohmmeter
RedWhite/ White 
						

							R530EWT
8 – 4
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
[9] I: NOISE FILTER TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the lead wires from the terminal the noise filter. Using an ohmmeter, check between
the terminals as described in the following table. If incorrect readings are obtained, replace the
noise filter.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
[10] 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.
Before testing,
1) Disconnect the power supply cord and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor. 
4) Disconnect the leads to the primary of the power transformer.
5) Ensure that these leads remain isolated from other components and oven chassis by using insulation tape.
1. Key Unit
NOTE:
1) Re-install the outer case (cabinet).
2) Reconnect the power supply cord after the outer case is installed.
3) Run the oven and check all functions.
The following symptoms indicate a defective 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. 
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) 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.MEASURING POINT INDICATION OF OHMMETER 
Between N and L Approx. 470kΩ
Between terminal N and GRAY Short circuit.
Between terminal L and RED Short circuit.
FUSE 20A
RESISTOR 470k
NOISE FILTER
NOISE SUPPRESSION COILLINE CROSS CAPACITOR
1.0μF / AC 250V
LINE BYPASS
CAPACITOR
0.0033μF / AC 250V LINE BYPASS
CAPACITOR
0.0033μF / AC 250VL
LOAD SOURCE
GRAY
N 
						

							R530EWT
8 – 5
g) The figure of all digits flicker.
3) Other possible problems caused by defective control unit.
a) Buzzer does not sound or continues to sound.
b) Clock does not operate properly.
c) Cooking is not possible.
3. If the Key unit or the Control unit is defective.
1) Disconnect the power supply cord, and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Replace the Control unit assembly.
5) Reconnect all leads removed from components during testing.
6) Re-install the outer case (cabinet).
7) Reconnect the power supply cord after the outer case is installed.
8) Run the oven and check all functions.
4. When testing is completed,
1) Disconnect the power supply cord and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor. 
4) Reconnect all leads removed from components during testing.
5) Re-install the outer case (cabinet).
6) Reconnect the power supply cord after the outer case is installed.
7) Run the oven and check all functions.
[11] K: KEY UNIT TEST
1. Disconnect the power supply cord, and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. 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 con-
tacts 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 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.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
[12] L: RELAY TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the leads to the primary of the power transformer.
5. Ensure that these leads remain isolated from other components and oven chassis by using insulation tape. 
6. After that procedure, re-connect the power supply cord.
G1 G2 G3 G4 G5 G6 G7 G8
G9
G10
G11
G12
G13
G14
Fresh
vegetablesBeverage
Center
Breakfast Lunch
Popcorn Snacks From the
Pantry
Start
Touch On
Fish
SeafoodPower
Level
Keep
Warm
Plus
15
Minute
Recipes
Defrost
CenterCustom
HelpBaked
potatoesSensor
reheatMinute
Plus
VegetablesRice
1
62
73
84
95
0
Poultry Ground
meat
EntreesTimer
Clock
Stop
Clear 
						

							R530EWT
8 – 6
7. Remove the outer case and check voltage between the cabinet side terminal of the relay RY1 and Pin No. 1 of 2 pin connector (A) 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 unit is defective.
8. Disconnect the power supply cord and then remove outer case.
9. Open the door and block it open.
10.Discharge high voltage capacitor.
11. Reconnect all leads removed from components during testing.
12.Re-install the outer case (cabinet).
13.Reconnect the power supply cord after the outer case is installed.
14.Run the oven and check all functions.
[13] M: DEFROST CENTER TEST
WARNING:The oven should be fully assembled before following procedure.
1. Open the door.
2. Place one cup of water in the center of the turntable tray in the oven cavity.
3. Close the door, touch the Defrost Center pad and touch the number pad 5. And touch the number pad 5 again. And touch the Start pad.
4. The oven is in Defrost cooking condition.
5. The oven will operate as follows.
6. If improper operation is indicated, the control unit is probably defective and should be checked.
[14] N: FOIL PATTERN ON THE PRINTED WIRING BOARD TEST
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.
1. Foil pattern check and repairs.
1) Disconnect the power supply cord and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Follow the troubleshooting guide given below for repair. 
5) Make a visual inspection of the varistor. Check for burned damage and examine the trans-
former with a tester for the presence of layer short-circuit (check the primary coil resistance
which is approximately 210Ω±15%). If any abnormal condition is detected, replace the con-
trol unit.
6) Reconnect all leads removed from components during testing.
7) Re-install the outer case (cabinet).
8) Reconnect the power supply cord after the outer case is installed.
9) Run the oven and check all functions.
2. Follow the troubleshooting guide given below, if indicator does not light up after above
check and repairs are finished.
1) Disconnect the power supply cord and then remove outer case.
2) Open the door and block it open.RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS
RY1 Approx. 24.0V D.C. Oven lamp / Turntable motor / Cooling fan motor
RY2 Approx. 23.0V D.C. Power transformer
MENU 1ST STAGE  2ND STAGE
Steaks/Chops or Fish LEVEL TIME LEVEL TIME
0.5lb 70% 30sec. 40% 15sec.
STEPS OCCURRENCE CAUSE OR CORRECTION
1 Only pattern at “a” is broken. *Insert jumper wire J1 and solder.
2 Pattern at “a” and “b” are broken. Replace the control unit.
T1
AC
VRS1OMIF
DU
CN-A
(J1)
ab
c d
12
XA
VH 
						

							R530EWT
8 – 7
3) Discharge high voltage capacitor.
4) Disconnect the leads to the primary of the power transformer.
5) Ensure that these leads remain isolated from other components and oven chassis by using insulation tape.
6) After that procedure, re-connect the power supply cord.
7) Follow the troubleshooting guide given below for repair.
8) Disconnect the power supply cord and then remove outer case.
9) Open the door and block it open.
10)Discharge high voltage capacitor.
11)Reconnect all leads removed from components during testing.
12)Re-install the outer case (cabinet).
13)Reconnect the power supply cord after the outer case is installed.
14)Run the oven and check all functions.
[15] O: AH SENSOR TEST
Checking the initial sensor cooking condition
WARNING: The oven should be fully assembled before following procedure.
1) The oven should be plugged in at least two minutes before sensor cooking.
2) Room temperature should not exceed 35°C.
3) The unit should not be installed in any area where heat and steam are generated. The unit should not be installed, for example, next to a conven-
tional surface unit. Refer to the “INSTALLATION Instructions”.
4) Exhaust vents are provided on the back of the unit for proper cooling and air flow in the cavity. To permit adequate ventilation, be sure to install so
as not to block these vents. There should be some space for air circulation.
5) Be sure the exterior of the cooking container and the interior of the oven are dry. Wipe off any moisture with a dry cloth or paper towel.
6) The Sensor works with food at normal storage temperature. For example, chicken pieces would be at refrigerator temperature and canned soup at
room temperature.
7) Avoid using aerosol sprays or cleaning solvents near the oven while using Sensor settings. The sensor will detect the vapor given of by the spray
and turn off before food is properly cooked.
8) After the oven is started on sensor cooking condition, if the sensor has not detected the vapor of the food, ERROR will appear and the oven will
shut off.
Water load cooking test
WARNING: The oven should be fully assembled before following procedure.
Make sure the oven has been plugged in at least two minutes before checking sensor cook operation. The cabinet should be installed and screws
tightened.
1) Fill approximately 200 milliliters of tap water in a 1000 milliliter measuring cup.
2) Place the container on the center of tray in the oven cavity.
3) Close the door.
4) Touch the TIMER/CLOCK pad once, the POWER LEVEL pad twice and the START pad once. And touch the number pad 1. Now, the oven is in
the sensor cooking condition, and “TEST”, “SENSOR” and “COOK” will appear in the display.
5) The oven will operate for the first 16 seconds, without generating microwave energy.
NOTE: ERROR will appear if the door is opened or STOP/CLEAR pad is touched during first stage of sensor cooking.
6) After approximately 16 seconds, microwave energy is produced.
If ERROR is displayed or the oven does not turn off, replace the AH sensor or check the control unit, refer to explanation below.  
1. TESTING METHOD FOR AH SENSOR AND/OR CONTROL UNIT
To determine if the sensor is defective, the simplest method is to replace it with a new replacement sensor.
1) Disconnect the power supply cord, and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Remove the AH sensor.
5)  Install the new AH sensor.STEPS OCCURRENCE CAUSE OR CORRECTION
1The rated AC voltage is not present between the cabinet side terminal of 
the relay RY1 and the Pin No. 1 of the 2-pin connector (A).Check supply voltage and oven power cord.
2The rated AC voltage is present at primary side of low voltage trans-
former.Low voltage transformer or secondary circuit defective.
Check and replace control unit.