R -3A54
R-3E54
TEST PROCEDURES (CONT’D)
PROCEDURE
LETTER
COMPONENT TEST
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 troubles 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.
d) Proper temperature measurement is not obtained.
RELAY TEST
1.
2.
3.
4.
5.
6.
CARRY OUT 3D CHECKS
Disconnect the leads from the primary of the power transfomer. Make sure that the leads re-
main isolated from other oven components and chassis. (Use insulation tape if necessary,)
Close the door.
Reconnect the supply.
Check the voltage between Pin Numbers 3 and 5 of 4-pin connector (A) on the control unit
with an A.C. voltmeter. The meter should indicated 240 volts, if no check oven circuit.
RYI AND RY2 TEST
These are operated by D.C. voltage. Check voltage at 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 di-
ode is good, control unit is defective.
RELAY SYMBOL
OPERATIONAL VOLTAGE
CONNECTED COMPONENTS
RYl
Approx. 26.5V.D.C.
Oven lamp/Turntable motor/Cooling fan motor
-____
RY2
Approx. 25.8V.D.C. Power transformer
15
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