Viking VHSO205SS Service Manual page 25

PROCEDURE
LETTER
V RELAY 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. Disconnect the leads to the primary of the power transformer.
5. Ensure that these leads remain isolated from other components and oven chassis by using insulation
tape.
6. After that procedure, re-connect the power supply cord.
7. Remove the outer case and check voltage between Pin Nos. 1 and 9 of the 5 pin connector (CN-D)
on the control unit with an A.C. voltmeter. The meter should indicate 40 volts, if not check oven
circuit.
Shut-off, Cook and Heater Relays Test
These relays are operated by D.C. voltage
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation, speed
grill, speed roast, speed bake, or convection cooking condition.
DC . voltage indicated . ................Defective relay.
DC. voltage not indicated .............Check diode which is connected to the relay coil. If diode is good,
RELAY SYMBOL
RY1
RY (COOK)
RY3
RY4
RY5
RY6
8. Disconnect the power supply cord, and then remove outer case.
9. Open the door and block it open.
10. D ischarge high voltage capacitor.
11. R econnect all leads removed from components during testing.
1. R e-install the outer case (cabinet).
13. R econnect the power supply cord after the outer case is installed.
14. R un the oven and check all functions.
W SOLID-STATE RELAY TEST
1. Disconnect the power supply and then remove outer case.
. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the wire leads from the solid-state relay.
5. Measure the resistance between the terminals as described in the following table, with an
ohmmeter.
6. If the meter does not indicate above resistance, replace the solid-state relay.
7. Reconnect all leads removed from components during testing.
8. Re-install the outer case (cabinet).
9. Reconnect the power supply cord after the outer case is installed.
X DEFROST TEST
WARNING : The oven should be fully assembled before following procedure.
(1) Place one cup of water in the center of the turntable tray in the oven cavity.
() Close the door, touch the Compu Defrost pad and select " Steaks/Chops " by touching Up/Down
TEST PROCEDURES
COMPONENT TEST
control unit is defective.
OPERATIONAL VOLTAGE
Approx. 7.0V D.C.
Approx. 5.0V D.C.
Approx. 5.0V D.C.
Approx. 5.0V D.C.
Approx. 5.0V D.C.
Approx. 5.0V D.C.
Terminals
Between 1 and 
Between 3 and 4
5
CONNECTED COMPONENTS
Oven lamp / Turntable motor
Power transformer
Convection motor
Damper motor
Fan motor
Convection motor
Resistance
Approx. 50MΩ
Approx. 1.3MΩ
VHSO205SS
1 
3 4
Solid-state relay