R-308JK
R-308JS
R-308JW
R-309JW
11
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
B POWER TRANSFORMER 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 primary input terminals and measure the resistance of the transformer with an ohmmeter.
Check for continuity of the coils with an ohmmeter. On the R x 1 scale, the resistance of the primary coil should
be less than 1 ohm and the resistance of the high voltage coil should be approximately 122 ohms for RTRN-
A715WRZZ or approximately 102 ohms for RTRN-A705WRZZ; the resistance of the filament coil should be
less than 1 ohm.
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.
(HIGH VOLTAGES ARE PRESENT AT THE HIGH VOLTAGE TERMINAL, SO DO NOT ATTEMPT TO
MEASURE THE FILAMENT AND HIGH VOLTAGE.)
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: silicon rectifier, high voltage capacitor and power transformer. 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 P-HI(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 32.1 to
59.7˚F(17.9 to 33.2˚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.
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. Isolate the rectifier from the circuit. Using the highest ohm scale of the meter, read the resistance across the
terminals and observe, reverse the leads to the rectifier terminals and observe meter reading. If a short is
C HIGH VOLTAGE RECTIFIER TEST
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