Sharp R-2397 Service Manual page 16

R-2397
PROCEDURE
K MAGNETRON THERMISTOR TEST
CARRY OUT 3D CHECKS.
Disconnect connector-H from the CPU unit. Measure the resistance of the thermistor with an
ohmmeter. Connect the ohmmeter leads to the leads of the thermistor.
If the meter does not indicate above resistance, replace the thermistor.
CARRY OUT 4R CHECKS.
EXHAUST THERMISTOR TEST
CARRY OUT 3D CHECKS.
Disconnect connector-B from the CPU unit. Measure the resistance of the thermistor with an
ohmmeter. Connect the ohmmeter leads to the leads of the thermistor.
If the meter does not indicate above resistance, replace the thermistor.
CARRY OUT 4R CHECKS.
INTAKE THERMISTOR TEST
CARRY OUT 3D CHECKS.
Disconnect connector-D from the CPU unit. Measure the resistance of the thermistor with an
ohmmeter. Connect the ohmmeter leads to the leads of the thermistor.
If the meter does not indicate above resistance, replace the thermistor.
CARRY OUT 4R CHECKS.
L MOTOR WINDING TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the motor. Using an ohmmeter, check the resistance between the two
terminals.
Resistance of Blower motor should be approximately 52 .
Resistance of Stirrer motor should be approximately 8.8 k .
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS.
M NOISE FILTER TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the terminals of noise filter. Using an ohmmeter, check between the
terminals as described in the following table.
TEST PROCEDURES
COMPONENT TEST
LETTER
Room Temp.
15˚C ........................ Approx. 15.91 k
20˚C ........................ Approx. 13.04 k
25˚C ........................ Approx. 10.74 k
Room Temp.
15˚C ........................ Approx. 77.45 k
20˚C ........................ Approx. 61.47 k
25˚C ........................ Approx. 49.12 k
Room Temp.
15˚C ........................ Approx. 15.88 k
20˚C ........................ Approx. 13.03 k
25˚C ........................ Approx. 10.74 k
14
Resistance
Resistance
Resistance