Sharp R-930AK-F Service Manual page 20

R-930AK-F
R-930AW-F
PROCEDURE
LETTER
8. Reconnect the power supply cord after the outer case is installed.
9. Run the oven and check all functions.
M DAMPER MOTOR TEST
When the power cord is plugged into the wall receptacle and 120 volts A.C. is supplied to the damper motor,
the motor operates until the damper is opened and the damper switch closes. Then the damper motor stops
operation.
If the damper motor does not operate, check for A.C. voltage with a voltmeter at the motor.
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. Disconnect the leads to the primary of the power transformer.
5. Ensure that the leads remain isolated from other components and oven chassis by using insulation tape.
6. Disconnect the wire leads of motor and connect the meter leads to the wire leads of main wire harness.
7. Re-connect the power cord into the wall receptacle.
8. If 120 volts A.C. is indicated at the wire leads, replace the motor and if 120 volts A.C. is not indicated, check
the wire harness and control unit.
9. Disconnect the power supply cord, and then remove outer case.
10. Open the door and block it open.
11. Discharge high voltage capacitor.
12. Reconnect all leads removed from components during testing.
13. Re-install the outer case (cabinet).
14. Reconnect the power supply cord after the outer case is installed.
15. Run the oven and check all functions.
N DAMPER SWITCH 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. Disconnect the leads to the primary of the power transformer.
5. Ensure that the leads remain isolated from other components and oven chassis by using insulation tape.
6. 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.
6-1. When switch actuator is pushed by the damper motor cam, the meter should be indicated a closed circuit.
6-2. 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.
7. If improper operation is indicated, replace the damper switch.
8. Disconnect the power supply cord, and then remove outer case.
9. Open the door and block it open.
10. Discharge high voltage capacitor.
11. Reconnect all leads removed from components during testing.
12. Re-install the outer case (cabinet).
13. Reconnect the power supply cord after the outer case is installed.
14. Run the oven and check all functions.
O CHECKING TEMPERATURE IN THE CONVECTION MODE
The following test procedure should be carried out with the microwave oven is a fully assembled
condition (outer case fitted).
It is difficult to measure the exact temperature in the convection oven. An accurate thermocouple type
temperature tester must be used. A low priced bi-metal type thermometer is not reliable or accurate.
The temperature should be checked with outer case cabinet installed, approx. 5 minutes after preheat
temperature is reached (audible signal sounds four times). The temperature experienced may be approx. 30˚F
more or less than indicated on the display, however, in most cases the food cooking results will be satisfactory.
Difference in power supply voltage will also affect the oven temperature. The Household power supply voltage
may sometimes become lower than the rated voltage (120 V) and cause under-cooking. If the power supply
voltage is 10% lower than the rated voltage, longer cooking time is required by 10% to 20%.
TEST PROCEDURES
COMPONENT TEST
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