6-2 Unsatisfactory Cooking
6-3 Part Check List
Parts
Cause
Diagnosis
Remedy
Food is
not heated.
1) Open cathode of
magnetron
Check the terminals with a multimeter to see
if the heater circuit is open.
Replace magnetron.
2) Defective
H. V. Diode
Check the H. V. Diode for continuity in the reverse and
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)
Replace H. V. Diode.
3) Shorted
magnetron
Connect megger leads to quick-connect terminal &
body of the magnetron if there is continuity, the
magnetron may be fuse will be blown) faulty. (In this
case the main fuse will be blown)
Replace magnetron.
4) Defective
magnetron
If there is a crack in the magnetron antenna (dome),
the magnetron is defective.
Replace magnetron.
5) Poor contact of
primary interlock
switch
Check if the screws are secured well to the door hinge.
and pressing it ON and OFF repeatedly.
Replace or adjust.
6) Open coil of
H. V. Trans-
former
Check the continuity of primary coil and secondary
coil. If there is no continuity, H. V. Transformer is
defective.
Replace the
H. V. Transformer.
7) Shorted H. V.
capacitor
Check the continuity of capacitor.
If the capacitor shorts, the fuse blows
Replace the
H. V. Capacitor.
8) Monitor fuse
blown out
Check the monitor fuse (on the noise filter)
Replace the
Monitor fuse
Symptom
Related Parts
Check Points
Remedy
Microwave
cooking does
not work.
H.V.Transformer
1) Check if the primary and secondary coil is open or shorted.
* Resistance of primary coil: . 2.5
Approx
Resistance of secondary coil: Approx. 151.5
2) Check if the MGT Heater Voltage is approx. 3.3V AC.
Caution : High voltage !
Replace.
H.V.Capacitor
Check continuity of capacitor between two
terminals with H.V.wire lead removed.
The resistance should be approx. 10M
Ω
, it’s failure..
Replace.
H.V.Diode
1) If there is no continuity in forward, direction the H.V.Diode is open.
2) If there is continuity in reverse direction, it’s shorted.
Replace.
Fan motor
does not
rotate.
Fan motor
Check if the motor coil is open.
Replace.
