Daewoo KOR-804M - Page 42

CAUTION:
1. High voltage is present at the high voltage terminal of the high voltage transformer during any cook cycle.
2. It is neither necessary nor advisable to attempt measurement of the high voltage.
3. Before touching any oven components or wiring, always unplug the oven from its power source and
discharge the capacitor (see page 20).
1. High voltage transformer
(A) Remove connections from the transformer ter-
minals and check continuity.
(B) Normal readings should be as follows:
Secondary winding ..... Approx. 940 +5%
Filament winding............. Approx. 00
Primary winding ............. Approx. 12
2. High voltage capacitor
(A) Check continuity of capacitor with meter on the
highest OHM scale.
(B) A normal capacitor will show continuity for a
short time, and then indicate 9MQ once the
capacitor is charged.
(C) A shorted capacitor will show continuous con-
tinuity.
(D) An open capacitor will show constant 9MOQ.
(E) Resistance between each terminal and chas-
sis should be infinite.
3. High voltage diode
(A) Isolate the diode from the circuit by disconnect-
' ing the leads.
(B) With the ohmmeter set on the highest resis-
tance scale, measure the resistance across the
diode terminals.
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Reverse the meter leads and again observe the
resistance reading. Meter with 6V, 9V or higher
voltage batteries should be used to check the
front-to-back resistance of the diode, otherwise
an infinite resistance may be read in both direc-
tions. A normal diodes resistance will be infinite
in one direction and several hundred KQ in the
other direction.
4. Magnetron
For complete magnetron diagnosis, refer to
“Measurement of the microwave output power”
(Page 14) continuity checks can only indicate
and open filament or a shorted magnetron. To
diagnose for an open filament or shorted
magnetron.
(A) Isolate magnetron from the circuit by discon-
ecting the leads.
(B) A continuity check across magnetron filament
terminals should indicate one ohm or less.
(C) Acontinuity check between each filament ter-
minal and magnetron case should read open.