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PROCEDURE
LETTER
A
MAGNETRON ASSEMBLY TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
4. To test for an open filament, isolate the magnetron from the high voltage circuit. A continuity check across
the magnetron filament leads should indicate less than 1 ohm.
5. To test for a shorted magnetron, connect the ohmmeter leads between the magnetron filament leads and
chassis ground. This test should indicate an infinite resistance. If there is little or no resistance the
magnetron is grounded and must be replaced.
6. Reconnect all leads removed from components during testing.
7. Reinstall the outer case (cabinet).
8. Reconnect the power supply cord after the outer case is installed.
9. Run the oven and check all functions.
MICROWAVE OUTPUT POWER
The following test procedure should be carried out with the microwave oven in a fully assembled condition
(outer case fitted).
HIGH VOLTAGES ARE PRESENT DURING THE COOK CYCLE, SO EXTREME CAUTION SHOULD BE
OBSERVED.
Power output of the magnetron can be measured by performing a water temperature rise test. This test should
only be used if above tests do not indicate a faulty magnetron and there is no defect in the following
components or wiring: inverter unit. This test will require a 16 ounce (453cc) measuring cup and an accurate
mercury thermometer or thermocouple type temperature tester. For accurate results, the following procedure
must be followed carefully:
1. Fill the measuring cup with 16 oz. (453cc) of tap water and measure the temperature of the water with a
thermometer or thermocouple temperature tester. Stir the thermometer or thermocouple through the water
until the temperature stabilizes. Record the temperature of the water.
2. Place the cup of water in the oven. Operate oven at POWER 10(HIGH) selecting more than 60 seconds
cook time. Allow the water to heat for 60 seconds, measuring with a stop watch, second hand of a watch
or the digital read-out countdown.
3. Remove the cup from the oven and again measure the temperature, making sure to stir the thermometer
or thermocouple through the water until the maximum temperature is recorded.
4. Subtract the cold water temperature from the hot water temperature. The normal result should be 39.2 to
63˚F(21.8 to 35˚C) rise in temperature. If the water temperatures are accurately measured and tested for
the required time period the test results will indicate if the magnetron tube has low power output (low rise
in water temperature) which would extend cooking time or high power output (high rise in water
temperature) which would reduce cooking time. Because cooking time can be adjusted to compensate for
power output, the magnetron tube assembly should be replaced only if the water temperature rise test
indicates a power output well beyond the normal limits. The test is only accurate if the power supply line
voltage is 120 volts and the oven cavity is clean.
B
INVERTER UNIT TEST
WARNING: DO NOT TOUCH THE COMPONENTS OF THE INVERTER UNIT WHILE INVERTER
CAUTION: DO NOT OPERATE INVERTER UNIT BY ITSELF.
CAUTION: DO NOT CONNECT THE OVEN TO WALL OUTLET WITHOUT THE OUTER CASE
Before checking the inverter unit, curry out following 4 steps.
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
4. Make sure that the wire leads and the connectors are connected correctly to the inverter unit, control unit
and magnetron.
TEST PROCEDURES
UNIT IS ENERGIZED. IT IS DANGEROUS BECAUSE THIS HAS HIGH VOLTAGE
COMPONENTS.
INSTALLED.
COMPONENT TEST
13
R-2110JK
R-2110JW
R-2120JK
R-2120JW
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