Samsung MW5490W Service Manual - Page 11

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: MODEL Secondary Filament Primary (Room temperature = 20ûC) MW5490W 88.0 W ± 10% Shows Continuity 0.32W ± 10% Primary Terminals Filament Terminals Secondary Terminal 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 Terminals 1~2(Input) 4~5(Output17V) 7~8(Output2.7V) Resistance SLV4270U 276.5W 9.245W 1.735W 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. Magnetron Antenna Gasket Plate Cooling Fins Samsung Electronics 5-1