Viking VHSO205SS Service Manual page 20

VHSO205SS
PROCEDURE
LETTER
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", even if the monitor switch operates normally. The
monitor fuse and monitor switch assembly is comprised of a 0 ampere fuse and switch.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
I BLOWN FUSE F10A
1. Disconnect the power supply cord.
. Remove the outer case cabinet, referring to "OUTER CASE CABINET REMOVAL".
3. Open the oven door and block it open.
4. Discharge the high voltage capacitor.
5. Remove the back plate from the oven, referring to "BACK PLATE REMOVAL".
6. If the monitor fuse is blown, there could be short or ground in high voltage rectifier, magnetron, power
transformer, high voltage capacitor or high voltage wire. Check them and replace the defective parts or
repair the wire harness.
7. Reconnect all leads removed from components during testing.
8. Reinstall the outer case (cabinet) and the back plate.
7. Reconnect the power supply cord after the outer case and back plate are installed.
8. Run the oven and check all functions.
CAUTION: ONLY REPLACE FUSE F10A WITH CORRECT VALUE REPLACEMENT.
J MAGNETRON TEMPERATURE FUSE TEST
1. Disconnect the power supply cord, and then remove outer case.
. 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 unless the
temperature of the magnetron reaches approximately 30
overheating of the magnetron. Check for restricted air flow to the magnetron, especially the cooling duct
and cooling fan.
5. Reconnect all leads removed from components during testing.
6. Reinstall 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 T HE T EMPERATURE FUSE INDICATES AN OPEN CIRCUIT AT ROOM T EMPERATURE,
K THERMAL CUT-OUT (TOP HEATER) TEST
1. Disconnect the power supply cord, and then remove outer case.
. Open the door and block it open.
3. Discharge high voltage capacitor.
4. A continuity check across the thermal cut-out terminals should indicate a closed circuit unless the
temperature of the thermal cut-out reaches approximately 338
automatically at approximately 311
replace the same item as in the parts list.
An open thermal cut-out indicates overheating of the top heating element unit. Check for restricted air
flow to the top heat element unit through the vent holes of the oven cavity, especially the heater duct
upper and convection fan.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
TEST PROCEDURES
RELAY, SECONDARY INTERLOCK SWITCH, DOOR SENSING SWITCH AND MONITOR
SWITCH FOR PROPER OPERATION.
REPLACE TEMPERATURE FUSE.
ο
COMPONENT TEST
ο ο
F(150
ο
F(155 C). If thermal cut-out has opened under normal condition,
0
C). An open temperature fuse indicates
ο ο
F(170 C). The thermal cut-out resets