R-222T(W)
8 – 5
[13] Procedure M: RELAY TEST
CARRY OUT 3D CHECKS.
Remove the outer case and check voltage between the Pin No. 1 of 3 pin connector (A) and the normal open terminal of the relay RY2 on the control
unit with an A.C. voltmeter. The meter should indicate 230 - 240 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.
CARRY OUT 4R CHECKS.
[14] Procedure N: 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.
NOTE: *At the time of making these repairs, make a visual inspection of the varistor.
Check for burned damage and examine the transformer with a tester for the
presence of layer short-circuit (check the primary coil resistance). If any
abnormal condition is detected, replace the defective parts.
CARRY OUT 4R CHECKS.
RELAY SYMBOL
OPERATIONAL VOLTAGE
CONNECTED COMPONENTS
RY1
Approx. 13.9 D.C.
Oven lamp / Turntable motor / Cooling fan motor
RY2
Approx. 12.7V D.C.
Power transformer
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The rated AC voltage is not present Pin No. 1 of 3 pin connector (A) and the
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Check supply voltage and oven power cord.
2
The rated AC voltage is present to primary side of low voltage transformer.
Low voltage transformer or secondary circuit defective.
Check and repair.
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