R-25JT-F
16
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
4. If the monitor fuse is blown when the door is opened, check the primary interlock relays RY2, RY3,
secondary interlock switches (1), (2) and monitor switches (1), (2) according to the "TEST PROCEDURE"
for those switches before replacing the blown monitor fuse.
CAUTION: BEFORE REPLACING A BLOWN MONITOR FUSE, TEST THE PRIMARY INTERLOCK
RELAYS, SECONDARY INTERLOCK SWITCHES, DOOR SENSING SWITCH AND MONITOR
SWITCHES FOR PROPER OPERATION.
If the monitor fuse is blown by improper switch operation, the monitor fuse and monitor switch must be
replaced with "monitor fuse and monitor switch assembly" part number
, even if the
monitor switch operates normally. The monitor fuse and monitor switch assembly is comprised of a 20
ampere fuse and switch.
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.
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BLOWN MONITOR FUSE TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
4. A continuity check across the temperature fuse terminals should indicate a closed circuit unless the
temperature of the temperature fuse reaches specfied temperature as shown below.
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TEMPERATURE FUSE TEST
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.
CAUTION: IF THE TEMPERATURE FUSE INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE,
REPLACE TEMPERATURE FUSE.
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THERMISTOR TEST
Magnetron (1) Failure:
Test magnetron (1) and Blower fan motor.
Magnetron (1), (2) Failure: Test magnetron (1), (2).
Check blower fan motor and ventilation opening.
Magnetron (2) Failure:
Test magnetron (2) and Blower fan motor.
Food has been burned in oven.
Temperature of oven inside is very high.
Oven temperature
fuse
Magnetron tempera-
ture fuse (2)
M a g n e t r o n t e m -
perature fuse (1)
150˚C
120˚C
Non resetable
type
EE1
EE3
EE2
Oven shut
off
Non resetable
type
Open
Close
Display or
temperature
temperature
Condition
Check point
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge two high voltage capacitors.
4. Follow the procedures below for each thermistor.
4-1. MAGNETRON THERMISTOR TEST
Disconnect connector-H from the CPU unit. And disconnect the connector of the magnetron thermistor from
the switch harness. Measure the resistance of the thermistor with an ohmmeter. Connect the ohmmeter leads
to the leads of the thermistor.
