Viking DMOR206SS Service Manual page 25

PROCEDURE
LETTER
I BLOWN MONITOR FUSE
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. If the monitor fuse is blown when the door is opened, check the primary interlock relay, secondary
interlock switch and monitor switch according to the "TEST PROCEDURE" for those switches before
replacing the blown monitor fuse.
CAUTION: BEFORE REPLACING A BLOWN MONITOR FUSE, TEST THE PRIMARY INTERLOCK
If the monitor fuse is blown by improper switch operation, the monitor fuse and monitor switch must
be replaced with "monitor fuse and monitor switch assembly" part number FFS-BA018/KiT, even if
the monitor switch operates normally. The monitor fuse and monitor switch assembly is comprised
of a 20 ampere fuse and switch.
5. Reconnect all leads removed from components during testing.
6. Re-install the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
J TEMPERATURE FUSE TEST
MAGNETRON TEMPERATURE FUSE
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. A continuity check across the temperature fuse terminals should indicate a closed circuit. If the
temperature of the magnetron reaches approximately 302
An open temperature fuse indicates overheating of the magnetron. Check for restricted air flow to
the magnetron, especially the cooling fan air guide.
5. Reconnect all leads removed from components during testing.
6. Re-install the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
CAUTION: IF THE TEMPERATURE FUSE INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE,
K HOOD THERMAL CUT-OUT TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. A continuity check across the thermal cut-out terminals should indicate an open circuit unless the
temperature of the thermal cut-out reaches approximately 140
the contacts will close. The thermal cut-out opens automatically at approximately 113
5. Reconnect all leads removed from components during testing.
6. Re-install the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
L THERMISTOR TEST
Disconnect connector-E from the control unit. Measure the resistance of the thermistor with an ohm-
meter. Connect the ohmmeter leads to Pin No's E-3 and E-4.
If the meter does not indicate above resistance, replace the thermistor
TEST PROCEDURES
RELAY, SECONDARY INTERLOCK SWITCH, DOOR SENSING SWITCH AND MONITOR
SWITCH FOR PROPER OPERATION.
REPLACE THE TEMPERATURE FUSE.
Room Temperature
O O O O
68F (20 C) - 86 F(30 C)
COMPONENT TEST
O F(150
O F(60
Resistance
Approx. 360 k ohm - 152 k ohm
25
O C), the temperature fuse opens.
O C) or more. At that temperature,
O F(45 O
DMOR206SS
C).