R-3A55
K
RELAY TEST
CARRY OUTm 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 indicat 240 volts, if not check oven circuit.
RYl and RY2 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.
t
I
/ OPERATIONAL 1
RELAY SYMBOL j
I
VOLTAGE /
CONNECTED COMPONENTS
I
RYI
1 Approx. 26.0 V.C.C.
Oven lamp/Turntable motor/Cooling fan motor
I
RY2 / Approx. 25.0 V.D.C.
Power transformer
CARRY OUT @ CHECKS
L 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 30 CHECKS
STEPS j OCCURANCE
CAUSE OR CORRECTION
1
The rated AC voltage is not present at
Check supply voltage and oven power cord.
POWER terminal of CPU connector (CN-A)
The rated AC voltage is present at primary
side of low voltage transformer.
Only pattern at “a” is broken.
Pattern at “a” and “b” are broken.
Low voltage transformer or secondary circuit defective.
Check and repair.
*Insert jumper wire Jl and solder. (CARRY OUT 30
CHECKS BEFORE REPAIR)
*Insert the coil RCILF2003YAZZ between “c” and “d”.
(CARRY OUTS CHECKS BEFORE REPAIR)
NOTE: At the time of these repairs, make a visual
inspection of the varistor for burning damage and
examine the transformer with tester for the pres-
ence of layer short-circuit (check primary coil resis-
tance). If any abnormal condition is detected, re-
place the defective parts.
CARRY OUT =CHECKS
15
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