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6-2. Safety Caution
A. SINCE NEARLY 4,000 VOLTS EXISTS IN SOME
CIRCUITS OF THIS UNIT REPAIRS SHOULD
BE CARRIED OUT WITH GREAT CARE.
The filament leads of the magnetron carry High
Voltage with respect to the ground. Extreme
caution must be exercised. Never plug the
unit into a power source to determine which
component is defective in the high voltage
section.
B. TO AVOID POSSIBLE EXPOSURE TO
MICROWAVE ENERGY LEAKAGE, THE
FOLLOWING PRECAUTIONS MUST BE TAKEN
BEFORE SERVICING.
(1) Before the power is applied:
(a) Make sure the primary interlock switch, the
secondary interlock switch and the interlock
monitor switch operate properly by opening
and closing the door several times.
(b) Make sure the perforated screen and the
dielectric choke of the door are correctly and
firmly mounted.
(2) After power is applied:
(a) Make sure the interlock switch mechanism
is operating properly by opening and closing
the door.
(b) Check microwave energy leakage must be
below the limit of 5 mW/cm 2 .
(All service adjustments should be made for
minimum microwave energy leakage
readings).
6-3. Self diagnosis (humidity Sensor and PCB thermistor check) &
Error code
1. Press "Defrost weight/time" for 2 seconds , unit
will display "TEST" and Beep once;
Error code
Symptom
F-1
PCB thermistor short
F-2
PCB thermistor open
F-4
Humidity sensor open or short
(3) Do not operate the unit until it is completely
repaired. If any of the following conditions exist,
the unit must not be operated.
(a) The door does not close firmly.
(b) The hinge is broken.
(c) The door seal is damaged.
(d) The door is bent or warped, or there is any
other visible damage on the unit that may
cause microwave energy leakage.
NOTE: Always keep the seal clean.
(e) Make sure that there are no defective parts
in the interlock mechanism.
(f) Make sure that there are no detective parts
in the microwave generating and
transmission assembly (especially
waveguide).
(4) The following items should be checked after the
unit is repaired:
(a) The interlock monitor switch is connected
correctly and firmly.
(b) The magnetron gasket is properly positioned
and mounted.
(c) The waveguide and the oven cavity are
intact. (no microwave energy leakage)
(d) The door can be properly closed and the
safety switches work properly.
(e) The unit must stop when the door is opened
or the time is up.
The unit must not be operated with any of the above
components removed or bypassed.
2. The unit will check if the PCB humidity sensor and
PCB thermistor are short or open.
3. If it has an error, it will beep and display an error
code.
4. If the unit is normal , it will beep and display
"PASS".
5. Press " Clear" to return to Standby mode.
-12-
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Table of Contents
Troubleshooting
