Samsung CM1819 Troubleshooting

Samsung Electronics

6. Troubleshooting

PRECAUTION

1. CHECK GROUNDING BEFORE CHECKING FOR TROUBLE.

2. BE CAREFUL OF THE HIGH VOLTAGE CIRCUIT.

3. DISCHARGE THE HIGH VOLTAGE CAPACITOR.

4. WHEN CHECKING THE CONTINUITY OF THE SWITCHES OR TRANSFORMER, DISCONNECT LEAD WIRES FROM THESE PARTS AND THEN CHECK CONTINUITY WITHOUT THE POWER SOURCE ON. TO DO OTHERWISE MAY RESULT IN A FALSE READING OR DAMAGE TO YOUR METER.

5. DO NOT TOUCH ANY PART OF THE CIRCUIT OR THE CONTROL CIRCUIT BOARD, SINCE STATIC DISCHARGE MAY DAMAGE IT. ALWAYS TOUCH GROUND WHILE WORKING ON IT TO DISCHARGE ANY STATIC CHARGE BUILT UP.

6-1 Electrical Malfunction

SYMPTOM CAUSE CORRECTIONS

Oven is dead. 1. Open or loose lead wire harness Check magnetron or cavity thermal cutout Fuse is OK. 2. Open thermal cutout (magnetron, cavity) switch is defective. No display and no 3. Open low voltage transformer Check Ass'y PCB when LVT is defective. operation. 4. Defective Ass'y PCB

No display and no 1. Shorted lead wire Check adjustment of primary, interlock operation 2. Defective primary latch switch (NOTE1) monitor, door sensing switch. Fuse blown out. 3. Defective monitor switch (NOTE1) (10A, 1.6A) 4. Shorted HVCapacitor

5. Shorted HVTransformer (NOTE2) NOTE 1: All of these switches must be replaced at the same time.

(refer to adjustment instructions)

Check continuity of main or power relay contacts and if it has continuity, replace main or power relay also.

NOTE 2: When HVTransformer is replaced, check diode and magnetron also.

Oven does not accept 1. Key input is not in-Sequence Refer to operation procedure. key input (Program) 2. Open or loose connection of membrane (CM1829/1429) key pad to Ass'y PCB

3. Shorted or open membrane panel

4. Defective Ass'y PCB Replace PCB main.

1. Open or loose connection of high voltage Adjust door and latch switches. circuit especially magnetron filament circuit

NOTE: Large contact resistance will bring

lower magnetron filament voltage and Timer starts countdown cause magnetron to lower output and/or but no microwave intermittent oscillation. oscillation. 2. Defective high voltage components Check high voltage component (No heat while oven lamp H.V.Transformer according to component test procedure and fan motor turn on.) H.V.Capacitor and replace if defective.

H.V.Diode, H.V.Fuse Magnetron

Samsung Electronics

Troubleshooting

SYMPTOM CAUSE CORRECTIONS

Oven lamp goes off 1. Loose lead wire or open lamp Tighten lamp lead wire or replace with

filament a new lamp

2. Misadjustment of latch switch

3. Defective latch switch

Microwave output is low;. 1. Decrease in power source voltage. Consult electrician. Oven takes longer time 2. Open or loose wiring of magnetron to cook food. filament circuit. (Intermittent oscillation) (No heat while oven lamp 3. Aging of magnetron and ventilation motor.) 4. Defective high voltage components Check high voltage component

H.V.Transformer according to component test procedure H.V.Capacitor and replace if defective. H.V.Diode,H.V.Fuse Magnetron

Oven does not operate and Defective Ass'y PCB Replace Ass’y PCB. return to plugged-in mode.

Loud buzzing noise can 1. Loose fan and ventilation motor Tighten screws of ventilation motor. be heard. 2. Loose screws on H.V.Transformer Tighten screws of H.V.Transformer.

3. Shorted H.V.Diode Replace H.V.Diode.

4. Loose or missing screws on Tighten screws of Cover-Back Cover-Back

Drive motor not 1. Open or loose wiring of drive motor. Check the wire of drive motor work. (Assy stirrer 2. Defective drive motor. Replace drive motor. does not rotate.) 3. Defective ass’y stirrer Replace ass’y stirrer.

Oven stops operating 1. Operation of thermal cutout Adjust door and latch switches. during cooking. (Magnetron or Cavity)

2. Ventilation motor does not rotate. Replace ventilation motor.

Sparks 1. Metallic ware or cooking dishes Inform the customer of proper use.

touching on the oven wall.

2. Ceramic ware trimmed with gold or Do not use any type of cookware silver powder also causes sparks. with metallic trimming.

Uneven cooking Uneven intensity of microwave due to Wrap thinner parts of the food with

its characteristics. aluminum foil.

Use plastic wrap or cover with a lid. Stir once or twice while cooking foods such as soup, cocoa, or milk.

Noise from turntable motor Noise may result from the motor. Replace turntable motor. when it starts to operate.

Oven can program but Defective circuitry of Start function Check circuitry of Start function timer does not start. of Main PCB Ass’y. of Main PCB Ass’y and replace if

defective.

Loose lead wires Adjust or repair loose wires.

6-1 Electrical Malfunction(continued)

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