Samsung M745R, Service Manual

Samsung Electronics

5. Alignment and Adjustments

5-1 High Voltage Transformer

5-2 Low Voltage Transformer

5-3 Magnetron

5-1

1. Remove connectors from the transformer terminals

and check continuity. 

2. Normal resistance readings are as follows:

(Room temperature = 20ûC)

1. Continuity checks can indicate only an open

filament or a shorted magnetron. To diagnose an
open filament or shorted magnetron :

2. Isolate the magnetron from the circuit by

disconnecting its leads.

3. A continuity check across the magnetron filament

terminals should indicate one ohm or less.

4. A continuity check between each filament terminal

and magnetron case should read open.

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.

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.

Filament Terminals 

Secondary

Terminal

Primary
Terminals

MODEL

M745

Secondary

Approx. 130

Ω

Filament

Approx.0

Ω

Primary

Approx.1.700

Ω

Terminals

Resistance

1~2(Input)

1,201

Ω

3~4(Output 7V)

4.348

Ω

5~6(Output17V)

21.72

Ω

Cooling Fins

Gasket Plate

Magnetron Antenna