R-210D
12
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
L
CONTROL PANEL ASSEMBLY TEST
The control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore,
unlike conventional microwave ovens, proper maintenance can not be performed with only a
voltmeter and ohmmeter.
In this service manual, troubleshooting by replacement is described according to the symptoms
indicated.
1. Control Panel
The following symptoms indicate a defective control unit.
1-1 In connection with LEDs
a) At a certain LED, all or some LEDs do not light up.
b) At a certain LED, brightness is low.
c) Only one LED does not light up.
d) All or some LEDs continue to light up.
e) A certain group of LEDs do not light up.
f) The LEDs flicker.
1-2 Tact switch
a) When touching a tact switch, a tact switch produces no signal.
1-3 Other possible troubles caused by defective control unit.
a) Buzzer does not sound or continues to sound.
b) Cooking is not possible.
c) Cooking time can not be set.
d) Power level can not be set.
M
TACT SWITCH TEST
1. CARRY OUT 3D CHECKS.
2. Remove the control unit from the control panel.
3. By using an ohmmeter, check the tact switch operation.
4. When the tact switch is not depressed, an ohmmeter should indicate an open circuit. When the
tact switch is depressed, an ohmmeter should indicate a short circuit. If improper operation is
indicated, the tact switch is probably defective and should be checked.
5. CARRY OUT 4R CHECKS after test.
CARRY OUT 3D CHECKS.
Remove the outer case and check voltage between Pin Nos. 3 and 5 of the 3 pin connector (A) on
the control unit with an A.C. voltmeter.
The meter should indicate 230-240 volts, if not check oven circuit.
Relay Test
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. -11.4V D.C.
Oven lamp / Turntable motor / Fan motor
RY2
Approx. -11.0V D.C.
High voltage transformer
CARRY OUT 4R CHECKS.
N
RELAY TEST
