R-3A54
R-3E54
TEST PROCEDURES (CONT’D)
PROCEDURE
LETTER
COMPONENT TEST
F
THERMAL CUT-OUT TEST
CARRY OUT 30 CHECKS
Disconnect the leads from the terminals of the thermal cut-out. Then using an ohmmeter, make
a continuity test across the two terminals as described in the table below.
CARRY OUT $FJ CHECKS
Table: Temberature Fuse or Thermal Cut-out Test
Parts Name
Temperature of “ON”
Temperature of “OFF”
condition (closed circuit).
condition (open circuit).
Thermal cut-out
(Magnetron) -20°C
I
Thermal cut-out
(Oven)
I
-2ok
Indication of ohmmeter
(When room temperature is
approx. 20°C.)
145Oc Closed circuit
145°C
I
Closed circuit
If incorrect readings are obtained, replace the thermal cut-out.
An open circuit thermal cut-out
(Magnetron) indicates that the magnetron has overheated, this may be due to resistricted venti-
lation, cooling fan failure or a fault condition within the magnetron or HV circuit.
An open circuit thermal cut-out (Oven) indicates that the foods in the oven may catch fire, this
may be due to over heating produced by improper setting of the cooking timer or failure of the
control panel.
G
MONITOR RESISTOR TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the monitor resistor or surge resistor.
Using an ohmmeter and set on a low range.
Check between the terminals of the monitor resistor or surge resistor as described in the follow-
ing table.
Table: Resistance
I
Resistor I Resistance I
I
Monitor resistor
I
Approx. 0.8 ohms
I
If incorrect readings are obtained, replace the monitor resistor or surge resistor
CARRY OUT 4R CHECKS.
H
MOTOR WINDING TEST
CARRY OUT 3D CHECKS
Disconnect the leads from the motor. Using an ohmmeter, check the resistance between the two
terminals as described in the table below.
Table: Resistance of Motor
Motors
Resistance
Fan motor
Approximately 326 ohms
Turntable motor
1 Aooroximatelv 16.08 kohms I
If incorrect readings are obtained, replace the motor.
(Also refer to test procedure I)
CARRY OUT @ CHECKS
13