Samsung CO88R Troubleshooting

Samsung Electronics 6-3

7. 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 ONE LEAD WIRE 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.

7-1-1 Specification of weight sensor

-Range of weight measurement......in cooking: 0 - apprx. 2000g(Weight of over round dish)

(Specification of weight sensor: 0-apprx. 4000g)

7-1-2 Method of adjusting 0 point.

Operation Display in operation

1. Plug in the cord.

2. Open the door to put rotating
plate and round dish into range.

3. Close the door and press the "P/L ( )"
key and "( )" key simultaneously.

4. Open the door to put a weight of balance

of 1kg(or two of 500g) on the center of
round dish(Note 1).

5. Close the door and press simultaneously
the "P/L ( )" and "( ) keys.

6. Press the "Cancel" key.

7-1 Weight sensor

1. All the displays of display unit get on.

1. As above.

1. "00" display lights up. (Lamp in range turns on
and round dish rotates).

2. "285-335" light up after about 12 second.

1. Same as 3-2.

1. "11" display lights up. "11" gets out after about
12 seconds.

2. After about 3 seconds after "11" is out,
"35-65" light up.

1. "0" display lights up. (The inside lamp turns off
and rotation of the round dish stops).

(Note1) Substitute the weight of balance with a beaker of 1kg total weight filled with tap water).

Samsung Electronics6-4

Troubleshooting

7-1-4-1. What is the weight sensor

1. The weight sensor detects weights of objects such as assembly to set automatically optimum heating
time according to the weight determined, contributing to improvement of operation.

7-1-4-2. Features

a. Configuration of plate-spring :

Onto the structure comprising electric pole on PC board and plate spring(sensor plate),assembly the
driving axle, and let the axle to move, with the action of spring, to move the spring to measure
weight.

b. Condenser measuring type :

This is a method to measure weight asthat, when a load is exerted on axle the plate spring(sensor
plate) on driving axle will come down to enlarge the gap away from the sensor electric pole on the
fixed PC board and thus the electrostatic capacity will be changed, by which the oscillation of weight
sensor PC board changed, and it allows to measure the weight by.

7-1-4 Details of functions of Weight Sensor

L
o
a
d

axle

PC(Sensor pole)

Fixed axle

Driving axle

Frame

Panel(Sensor Panel)

RT motor

7-1-3 Method for checking 0 point

Items to check: Confirmation key Confirmation

Value at 0 point Regulation for CANCEL + MORE ( ) key, Display of previous regulated value at 0

simultaneously pressed. point, for example: 315

Value of inclination Regulation for CANCEL + LESS ( ) key, Display of previous regulated value

simultaneously pressed. of declination, for example: 49

7-1Samsung Electronics

7-1-4-3. Description of functions performance

a. Functions of weight sensor PC plate(oscillator)

a-1. Frequency of oscillation

-. Adjusting "0" point ----- appr.31 kHz

-. Loading 1000g on round plate ----- appr. 5kHz(indicating increment of 5kHZ from adjusting 0.)

a-2. Load exerted on axle and oscillating frequency(kHz)

7-1-4-4. Wiring diagram for measuring frequency

1. Do not apply heavy load or pressure on the rotating dish
(The weight sensor directly contact the rotating dish).
Putting food that exceeds 4kg(Total) can damage the weight sensor.

2. Use only genuine replacements that fit the model(C.E., rotating dish and supporter).

Frequency
(kHz)

0

0 V

-5 V

100pF

1000g

36

g Load

At "0" point

Oscillation
board K

Power

Frequency

counter

Vcc
Vss
Ws

7-1-5 Precautions

Troubleshooting