Unsatisfactory Cooking; Part Check List - Samsung M 735 Service Manual

6-2 Unsatisfactory Cooking

Parts
1) Open cathode
of magnetron
2) Defective
- H. V. Diode
3) Shorted
magnetron
Food is 4) Defective
not heated. magnetron
5) Poor contact
of primay
interlock sw itch
6) Open coil of
H. V. Trans-
former
7) Shorted H. V.
capacitor
8) M onitor fuse
blow n out

6-3 Part Check List

Symptom Related Parts
M icrow ave H.V.Transformer
cooking does
not w ork.
H.V.Capacitor
H.V.Diode
Fan motor Fan motor
does not rotate.
Samsung Electronics
Cause
Check the terminals w ith a multimeter to see
if the heater circuit is open.
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 w ill be hot)
Connect megger leads to quick-connect terminal &
body of the magnetron if there is continuity, the
magnetron may be faulty. (In this case the main
fuse w ill be blow n)
If there is a crack in the magnetron antenna (dome),
the magnetron is defective.
Check if the screw s are secured w ell to the door hinge.
and pressing it ON and OFF repeatedly.
Check the continuity of primary coil and secondary
coil. If there is no continuity, H. V. Transformer is
defective.
Check the continuity of capacitor.
If the capacitor shorts, the fuse blow s
Check the monitor fuse
(on the noise filter)
1) Check if the primary and secondary coil is open or shorted.
* Resistance of primary coil: Approx. 2.30
Resistance of secondary coil: Approx. 123 §
2) Check if the M GT Heater Voltage is approx. 3.3V AC.
Caution : High voltage !
Check continuity of capacitor betw een tw o
terminals w ith H.V.w ire lead removed.
The resistance should be approx. 10M Ω , it's failure.
1) If there is no continuity in forw ard, direction the H.V.Diode is open.
2) If there is continuity in reverse direction, it's shorted.
Check if the motor coil is open.
Diagnosis
Check Points
§
Troubleshooting
Remedy
Replace magnetron.
Replace H. V. Diode.
Replace magnetron.
Replace magnetron.
Replace or adjust.
Replace the
H. V. Transformer.
Replace the
H. V. Capacitor.
Replace the
M onitor fuse
Remedy
Replace.
Replace.
Replace.
Replace.
6-3