Samsung CM1819 Troubleshooting

23

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

24

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)

25

Samsung Electronics

Troubleshooting

Code Cause Corrections

E1 1. Improper input power frequency Check if power frequency is 50Hz.

2. Defective Ass’y Main PCB Replace Ass’y Main PCB or MICOM.

E21 1. Thermistor sensor failure Check resistance of thermistor sensor

2. Thermistor sensor open and replace if defective.

3. Loose connector CN2 Check the circuitry around thermistor sensor.

E22 1. Thermistor sensor failure Check resistance of Thermistor sensor

and replace if defective.

2. Thermistor sensor short If Thermistor sensor is short, replace.

3. Thermistor sensor wire short Check the circuitry around Thermistor sensor.

E3 1. Overheating inside cavity Check if the oven was operating

(no load or little load aging) without load or too little load

and plug the power cord in again.
If error code ‘E3’ appears again in the
window display, check resistance of
Thermistor sensor and replace if defective.

2. Air ventilation blocked around Check if any blocking amterials exist
exhaust area around the Air Exhaust or ventilation

openings and follow the instructions above.

3. Ventilation motor failure and Check if the ventilation motor is operative
magnetron overheating and replace the motor if defective.

E41 1. Main Relay (RY1) or Check Main Relay (RY1), Power Relay (RY2)

Power Relay (RY2) failure Primary S/W and Monitor S/W and replace

2. Loose lead wires of relay if defective.

3. Primary or Monitor S/W failure Check if lead wires are loosened and connect

firmly if loose.

4. Loose lead wires of Primary
or Monitor S/W

5. H.V.Trans input power sensing Check the circuitry and replace if defective.
circuitry failure (Refer to Operating Sequence as shown in page 42.)

E42 1. Power Relay (RY5) failure Check Power Relay2, Primary S/W, Monitor S/W

2. Loose lead wires of or Fuse and replace if defective.
Power Relay (RY5) Check if lead wires are loosened and repair as

3. Primary or Monitor S/W failure necessary.

4. Loose lead wires of
Primary or Monitor S/W

5. Fuse(10A) blown out on neutral
area of Ass’y Noise Filter

6. H.V.Trans input power sensing Check the circuitry. (Refer to Operating Sequence
circuit failure as shown in page 42.)

E5 1. Memory IC (EEPROM IC) failure Check Memory IC (IC3) and replace if defective.

(CM1829

/1429) 2. MICOM failure Replace Assy Main PCB or MICOM.

6-2 Error Codes & Corrections