Viking DMOC205SS User Manual
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DMOC205SS
VMOC205SS
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 approximately 10 M
Ω 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.
E
PRIMARY INTERLOCK SWITCH AND THIRD DOOR SWITCH TEST
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 switch.
F
SECONDARY INTERLOCK SYSTEM 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.
SECONDARY INTERLOCK RELAY
Disconnect two (2) wire leads from the tab terminal of the secondary interlock relay (RY2). 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.
G
MONITOR SWITCH
Disconnect the oven from power supply.
Before performing this test, make sure that the primary interlock switch and the secondary interlock relay
are operating properly, according to the above Test Procedures. 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 for continuity of
monitor circuit.
H
BLOWN MONITOR FUSE
If the monitor fuse is blown when the door is opened, check the primary interlock switch, door sensing
switch relay (RY1) and monitor switch according to the "TEST PROCEDURE" for those switches before
replacing the blown monitor fuse.
CAUTION: IF THE MONITOR FUSE IS BLOWN BY IMPROPER SWITCH OPERATION, THE
MONITOR FUSE AND SWITCH MUST BE REPLACED WITH "MONITOR FUSE AND
SWITCH ASSEMBLY" PART NUMBER FFS-BA012WRK0, EVEN IF THE MONITOR
SWITCH OPERATES NORMALLY. THE MONITOR FUSE AND SWITCH ASSEMBLY IS
PACKED WITH 20 AMPERE FUSE AND SWITCH.
I
OVEN THERMAL CUT-OUT (on the side of steam duct)
A continuity check across the thermal cut-out terminals should indicate a closed circuit unless the
temperature of the oven thermal cut-out reaches approximately 302
ο
F (150
ο
C). The thermal cut-out
reset automatically at approximately 266
ο
F (130
ο
C). If the thermal cut-out has operated under the normal
condition, replace the thermal cut-out. An open thermal cut-out indicates overheating of the oven cavity.
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
SCREW DRIVER
MONITOR SWITCH
OHMMETER
PRIMARY
INTERLOCK
SWITCH
COM.
N.C.