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PROCEDURE
LETTER
COMPONENT TEST
TEST PROCEDURES
C
D
E
(CONTINUED)
HIGH-VOLTAGE RECTIFIER TEST
1.
Disconnect power supply cord and remove outer cabinet case.
2.
Open 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 meter reading, then reverse the leads to the rectifier terminals and observe meter
reading. If a short is indicated in both directions, or if an infinite resistance is read in both directions, the
rectifier is probably defective and should be replaced.
NOTE:
Be sure to use an ohmmeter that will supply a forward bias voltage of more than 6.3 volts.
5.
Reconnect all leads removed from components during testing.
6.
Reinstall the outer cabinet case, then reconnect power supply cord.
7.
Run the oven and check all functions.
HIGH VOLTAGE CAPACITOR TEST
1.
Disconnect power supply cord and remove outer cabinet case.
2.
Open door and block it open.
3.
Discharge high-voltage capacitor.
4.
If the capacitor is open, no high voltage will be available to the magnetron. Disconnect input leads and
check for short or open between the terminals using an ohmmeter.
Checking with a high ohm scale, if the high voltage 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 either of the terminals and case. If it is
shorted, replace the capacitor.
5.
Reconnect all leads removed from components during testing.
6.
Reinstall the outer cabinet case, then reconnect power supply cord.
7.
Run the oven and check all functions.
CAVITY TEMPERATURE FUSE TEST
1.
Disconnect power supply cord and remove outer cabinet case.
2.
Open door and block it open.
3.
Discharge high-voltage capacitor.
4.
A continuity check across the cavity temperature fuse terminals should indicate a closed circuit unless the
temperature of the cavity temperature fuse reaches approximately 302°F (150°C). An open cavity tempera-
ture fuse indicates overheating of the oven, replace the cavity temperature fuse and check inside of oven
cavity and for improper setting of cooking time or operation of control unit. Check for restricted air flow
through the vent holes of the oven cavity, especially the cooling fan and air guide.
5.
Reconnect all leads removed from components during testing.
6.
Reinstall the outer cabinet case, then reconnect power supply cord.
7.
Run the oven and check all functions.
C/T FUSE TEST
1.
Disconnect power supply cord and remove outer cabinet case.
2.
Open door and block it open.
3.
Discharge high-voltage capacitor.
4.
A continuity check across the C/T fuse terminals should indicate a closed circuit unless the temperature of
the C/T fuse reaches approximately 302°F (150°C). An open C/T fuse indicates overheating of the mag-
netron. Replace the temperature fuse and check for restricted air flow to the magnetron, especially the
cooling fan air guide.
NOTE:
If the temperature fuse indicates an open circuit at room temperature, replace the temperature fuse.
5.
If the C/T fuse is blown when the door is opened, check the primary interlock relay, secondary
interlock switch and monitor switch according to the "TEST PROCEDURE" for those switches before
replacing the blown monitor fuse.
NOTE:
Before replacing a blown C/T fuse, test the primary interlock relay, secondary interlock switch and
monitor switch according to the test procedure for those switches before replacing the blown C/T fuse.
Troubleshooting & Tech Data
MW24-1100 MICROWAVE OVEN
6-5
#814888 - Revision A - May, 2009
