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16
R-90GCK
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
BLK
RED
WHT
Main Coil
3-pin
Connector
Connector
Sub Coil
Thermal
Cut-out
130˚C OFF
100˚C ON
100˚C ON
130
Ω
140
Ω
CONVECTION MOTOR
1. CARRY OUT 3D CHECKS.
2. Disconnect input leads and check for short or open between the terminals using an ohmmeter.
2. Disconnect input leads and check for short or open between the terminals using an ohmmeter.
Checking with a high ohm scale, if the capacitor is normal, the meter will indicate continuity for a
short time and should indicate an open circuit once the capacitor is charged. If the above is not
the case, check the capacitor with an ohmmeter to see if it is shorted between the terminals. If it
is shorted, replace the capacitor.
short time and should indicate an open circuit once the capacitor is charged. If the above is not
the case, check the capacitor with an ohmmeter to see if it is shorted between the terminals. If it
is shorted, replace the capacitor.
3. CARRY OUT 4R CHECKS.
R
CONVECTION MOTOR CAPACITOR TEST
1. CARRY OUT 3D CHECKS.
2. Remove the back plate from the oven, referring to “BACK PLATE REMOVAL”.
3. Disconnect the 3-pin connector of the convection motor from the main wire harness.
4. Measure the resistance of the convection motor with an ohmmeter.
2. Remove the back plate from the oven, referring to “BACK PLATE REMOVAL”.
3. Disconnect the 3-pin connector of the convection motor from the main wire harness.
4. Measure the resistance of the convection motor with an ohmmeter.
The resistance of the main coil, across the black and the red wires, should be approximately 130
ohms. The resistance of the sub coil, across the black and the white wires, should be
approximately 140 ohms.
ohms. The resistance of the sub coil, across the black and the white wires, should be
approximately 140 ohms.
5. Also, the convection motor has the thermal cut-out in it.
Measure the resistance of the main coil (or the sub coil). The resistance across the black and the
red wires (or across the black and the white wires) should be above resistance unless the
temperature of the thermal cut-out reaches approximately 130˚C. The thermal cut-out resets
automatically at 100˚C. If an ohmmeter
indicates an open circuit under normal
condition, replace the convection motor
because the thermal cut-out has opened. An
open thermal cut-out indicates overheating of
the convection motor. Check for restricted air
flow to the convection motor or a lock of the
convection fan, especially the fan motor (high
voltage transformer side).
red wires (or across the black and the white wires) should be above resistance unless the
temperature of the thermal cut-out reaches approximately 130˚C. The thermal cut-out resets
automatically at 100˚C. If an ohmmeter
indicates an open circuit under normal
condition, replace the convection motor
because the thermal cut-out has opened. An
open thermal cut-out indicates overheating of
the convection motor. Check for restricted air
flow to the convection motor or a lock of the
convection fan, especially the fan motor (high
voltage transformer side).
6. CARRY OUT 4R CHECKS.
S
CONVECTION MOTOR TEST
The following test procedure should be carried out with the microwave oven is a fully assembled
condition (outer case fitted).
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. 17˚C 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 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%.
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. 17˚C 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 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%.
T
CHECKING TEMPERATURE IN THE CONVECTION MODE
U
MOTOR WINDING TEST
1. CARRY OUT 3D CHECKS.
2. Remove the back plate from the oven, referring to “BACK PLATE REMOVAL”.
3. Disconnect the leads from the motor. Using an ohmmeter, check the resistance between the two
2. Remove the back plate from the oven, referring to “BACK PLATE REMOVAL”.
3. Disconnect the leads from the motor. Using an ohmmeter, check the resistance between the two
terminals as described in the table below.
Table: Resistance of Motor
Motors
Resistance
Fan motor
Approximately 77
Ω
Turntable motor
Approximately 12 k
Ω
Damper motor
Approximately 11 k
Ω
If incorrect readings are obtained, replace the motor.
4. CARRY OUT 4R CHECKS.
4. CARRY OUT 4R CHECKS.
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