Alignment And Adjustments; High Voltage Transformer; Low Voltage Transformer; Magnetron - Samsung CM1089A/XEU Service Manual

5. Alignment and Adjustments

PRECAUTION
1. High voltage is present at the high voltage terminals 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 high voltage capacitor .

5-1 High Voltage Transformer

1. Remove connectors from the transformer terminals and
check continuity .
2. Normal resistance readings are as follows:
Approx. 90Ω
Secondary
Approx. 0Ω
Filament
Approx. 1.2Ω
Primary
(Room temperature = 20°C)

5-2 Low Voltage Transformer

1. The low voltage transformer is located on the control
circuit board .
2. Remove the low voltage transformer from the PCB
Ass'y and check continuity .
3. Normal resistor reading is shown in the table .

5-3 Magnetron

Continuity checks can indicate only an open filament or
1.
a shorted magnetron. To diagnose an open filament or
shorted magnetron .
2. Isolate the magnetron from the circuit by disconnecting its
leads .
A continuity check across the magnetron filament terminals
3.
should indicate one ohm or less .
A continuity check between each filament terminal and
4.
magnetron case should read open .

5-4 High Voltage Capacitor

1. Check continuity of the capacitor with the meter set at the highest resistance scale .
Once the capacitor is charged, a normal capacitor shows continuity for a short time, and then indicates 9MΩ.
2.
3. A shorted capacitor will show continuous continuity .
An open capacitor will show constant 9MΩ.
4.
Resistance between each terminal and chassis should read infinite.
5.
Filament Terminals
Primary
Terminals
Terminals Resistance
1,713Ω
1~2(Input)
3~4(Output 2 .9V) 4.32Ω
39.1Ω
5~6(Output 13V)
Gasket Plate
Cooling Fins
17
Secondary
Terminal
Magnetron Antenna