Sharp R-995J Service Manual page 22

R-995J
PROCEDURE
LETTER
NOTE: *At the time of making these repairs, make a
visual inspection of the varistor. check for
burned damage and examine the transformer
with an ohmmeter for the presence of layer
short-circuit (check primary coil resistance).
If any abnormal condition is detected, replace
the defective parts.
Q AH SENSOR TEST
Checking the initial sensor cooking condition
(1) The oven should be plugged in at least five minutes before sensor cooking.
(2) Room temperature should not exceed 35˚C.
(3) The unit should not be installed in any area where heat and steam are generated. The unit should
not be installed, for example, next to a conventional surface unit. Refer to the INSTALLATION
INSTRUCTIONS of the operation manual.
(4) Exhaust vents are provided on the back of the unit for proper cooling and air flow in the cavity. To
permit adequate ventilation, be sure to install so as not to block these vents. There should be some
space for air circulation.
(5) Be sure the exterior of the cooking container and the interior of the oven are dry. Wipe off any
moisture with a dry cloth or paper towel.
(6) The Sensor works with food at normal storage temperature.For example, chicken pieces would
be at refrigerator temperature and canned soup at room temperature.
(7) Avoid using aerosol sprays or cleaning solvents near the oven while using Sensor settings. The
sensor will detect the vapor given of by the spray and turn off before food is properly cooked.
(8) After the oven is started on sensor cooking condition, if the sensor has not detected the vapor of
the food, ERROR will appear and the oven will shut off.
Water load cooking test
Make sure the oven has been plugged in at least five minutes before checking sensor cook operation.
The cabinet should be installed and screws tightened.
(1) Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup.
(2) Place the container on the center of tray in the oven cavity.
(3) Close the door.
(4) Touch REHEAT SENSOR pad five times and touch the INSTANT COOK/START pad. Now, the
oven is in the sensor cooking condition and "CASSE-", "ROLES", "CANNED", "FOOD", "SEN-
SOR" and "REHEAT" will appear in the display.
(5) The oven will operate for the first 16 seconds, without generating microwave energy.
When the AH sensor is defective (open or short), ERROR will appear in the display after 16 seconds
cleaning time.
If ERROR appears check sensor wire connections and/or AH sensor.
NOTE: ERROR will appear if the door is opend or STOP/CLEAR pad is touched during first stage of
sensor cooking.
(6) After approximately 16 seconds, microwave energy is produced, and the display start to count
down the remaining cooking time and the oven should turn off after water is boiling (bubling).
If the oven does not turn off, replace the AH sensor or check the control unit, refer to explanation
below.
To determine if the sensor is defective, the simplest method is to replace it with a new replacement
sensor.
(1) Disconnect oven from power supply and remove outer case.
(2) Discharge the high voltage capacitor.
(3) Remove the AH sensor.
(4) Install the new AH sensor.
(5) Re-install the outer case.
(6) Reconnect the oven to the power supply and check the sensor cook operation, proceed as follows:
TEST PROCEDURES
COMPONENT TEST
TESTING METHOD FOR AH SENSOR AND/OR CONTROL UNIT
20
d
b
a
c