17
R-1850
R-1851
D
HIGH VOLTAGE CAPACITOR TEST
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS
OR WIRING.
If the capacitor is open, no high voltage will be available to the magnetron. Disconnect input leads and
check for short or open between the terminals using an ohmmeter.
Checking with a high ohm scale, if the high voltage capacitor is normal, the meter will indicate continuity
for a short time and should indicate an open circuit once the capacitor is charged. If the above is not the
case, check the capacitor with an ohmmeter to see if it is shorted between either of the terminals and
case. If it is shorted, replace the capacitor.
Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal
of the switch. The meter should indicated an open circuit with the door open and a closed circuit with the
door closed. If improper operation is indicated, replace the secondary interlock switch.
E
SECONDARY INTERLOCK SWITCH TEST
DOOR SENSING SWITCH
Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal
of the switch, the meter should indicated an open circuit with the door open and a closed circuit with the
door closed. If improper operation is indicated, replace the door sensing switch.
NOTE: If the door sensing switch contacts fail in the open position and the door is closed, the oven lamp
will be activated by RY1.
PRIMARY INTERLOCK RELAY
Disconnect two (2) wire leads from the male tab terminals on the relay (RY2) provided in the control panel
assembly. Check the state of the relay contacts using a ohmmeter. The relay contacts should be open.
If the relay contacts are closed, replace the circuit board entirely or the relay itself.
F
PRIMARY INTERLOCK SYSTEM TEST
Disconnect the oven from power supply.
Before performing this test, make sure that the secondary interlock switch and the primary interlock relay
are operating properly, according to the above Switch Test Procedure. Disconnect the wire lead from
the monitor switch (NC) terminal. Check the monitor switch operation by using the ohmmeter as follows.
When the door is open, the meter should indicate a closed circuit. When the monitor switch actuator is
pushed by a screw driver through the lower latch hole on the front plate of the oven cavity with the door
opened (in this condition the plunger of the monitor switch is pushed in), the meter should indicate an
open circuit. If improper operation is indicated, the switch may be defective.
After testing the monitor switch, re-connect the wire
lead to the monitor switch (NC) terminal and check
the continuity of the monitor circuit.
G
MONITOR SWITCH
H
DAMPER SWITCH TEST
Disconnect the wire leads from the switch terminals and connect ohmmeter leads to the common (COM.)
and normally open (N.O.) terminals of the switch.
1. When switch actuator is pushed by the damper cam, the meter should be indicated a closed circuit.
2. When power cord is plugged into the wall receptacle, the damper motor operates and damper cam
will start to rotate. When the switch actuator is released, the meter should be indicated an open circuit.
If improper operation is indicated, replace the damper switch.
SCREW
DRIVER
MONITOR SWITCH
WHITE
BLACK
BLACK
