6-3
Parts
Cause
Diagnosis
Remedy
1) Open cathode
Check the terminals with a multimeter to see
Replace magnetron.
of magnetron
if the heater circuit is open.
2) Defective
Check the H. V. Diode for continuity in the reverse and
Replace H. V. Diode.
-
H. V. Diode
normal directions using megger. If there is continuity
in the reverse direction, the H. V. Diode may be faulty.
(In this event H. V. Capacitor will be hot)
3) Shorted
Connect megger leads to quick-connect terminal &
Replace magnetron.
magnetron
body of the magnetron if there is continuity, the
magnetron may be faulty. (In this case the main
fuse will be blown)
Food is
4) Defective
If there is a crack in the magnetron antenna (dome),
Replace magnetron.
not heated.
magnetron
the magnetron is defective.
5) Poor contact
Check if the screws are secured well to the door hinge.
Replace or adjust.
of primay
and pressing it ON and OFF repeatedly.
interlock switch
6) Open coil of
Check the continuity of primary coil and secondary
Replace the
H. V. Trans-
coil. If there is no continuity, H. V. Transformer is
H. V. Transformer.
former
defective.
7) Shorted H. V.
Check the continuity of capacitor.
Replace the
capacitor
If the capacitor shorts, the fuse blows
H. V. Capacitor.
8) Monitor fuse
Check the monitor fuse
Replace the
blown out
(on the noise filter)
Monitor fuse
6-2 Unsatisfactory Cooking
Symptom
Related Parts
Check Points
Remedy
Microwave
H.V.Transformer
1) Check if the primary and secondary coil is open or shorted.
Replace.
cooking does
* Resistance of primary coil: Approx. 2.30 Ω
not work.
Resistance of secondary coil: Approx. 123 Ω
2) Check if the MGT Heater Voltage is approx. 3.3V AC.
Caution : High voltage !
H.V.Capacitor
Check continuity of capacitor between two
Replace.
terminals with H.V.wire lead removed.
The resistance should be approx. 10M
Ω
, it's failure.
H.V.Diode
1) If there is no continuity in forward, direction the H.V.Diode is open.
Replace.
2) If there is continuity in reverse direction, it's shorted.
Fan motor
Fan motor
Check if the motor coil is open.
Replace.
does not rotate.
6-3 Part Check List
Troubleshooting
