R-3S56
12
TEST PROCEDURES (CONT'D)
PROCEDURE
LETTER
COMPONENT TEST
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.
If the display fails to clear when the STOP/CLEAR tact switch is depressed, first 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, make sure the door
sensing switch is closed (either close the door or short the door sensing switch connecter). Use the tact
switch matrix indicated on the control panel schematic and place a jumper wire between the pins that
correspond to the STOP/CLEAR tact switch making mo-
mentary contact. If the control unit responds by clearing
with a beep, the tact switch 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 tact switch is at fault.
K TACT SWITCH TEST
SW1 10 SW2 1
SW3 10
SW4
SW6
SW7
SW5
MIN.
MIN.
SEC.
AUTO COOK
STOP
CLEAR
START/
INSTANT COOK
SERVES/
POWER LEVEL
L RELAY 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 220 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 or convection cooking
operation.
DC. voltage indicated .................... Defective relay.
DC. voltage not indicated . ............ Check diode which is connected to the relay coil. If diode is good,
CARRY OUT 4R CHECKS.
RELAY SYMBOL
OPERATIONAL
VOLTAGE
CONNECTED COMPONENTS
RY1 Approx. 19.0V.D.C. Oven lamp/Turntable motor/Cooling fan motor
RY2 Approx. 18.0V.D.C. Power transformer
M 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.
CARRY OUT 3D CHECKS.
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