Samsung SG626, SG628, BG626, BG678, SG676 Troubleshooting

7. Troubleshooting

Precautions

1. Is the power cord well connected to wall outlet?

2. Refer to the reference

1) No power

Start

Measure C03
(1000M/35V)

Measure IC02
OUT voltage

Measure IC03
OUT voltage

DC-Trans primary

power input?

Y

DC-Trans secondary

power input?

Y

Main PCB fuse

brown out?

N

Power input to IC02?

Y

DC 12V output

from IC02?

Y

DC 5V output

from IC03?

N

Are wires connected to

panel securely?

Y

Panel PCB Ass’y

is OK?

Y

OK

N

Check wires

N

Replace DC-Trans

N

Replace fuse

N

Check BD05 – 08

N

Check IC02(MC7812)

N

Check IC03(KA7805)

N

Check wire connection

Y

Reference 1

(Page. 38)

Replace panel PCB

28 Samsung Electronics

2) Compressor does not run

Precautions

1. Compressor does not operate in 5 minutes after power ON and compressor OFF.

2. Compressor does not run during defrosting.

3.

Compressor does not run because low temperature is detected if freezer sensor is not connected.

Start

Reference 6

(Page. 40)

N

Replace MICOM
and PCB

N

Replace IC07

N

Replace relay

5 minutes after

compressor off?

Y

Is compressor

operated by forse?

N

Reference 7

MICOM pin24

output is “HIGH ”?

Y

IC07 pin10 output

is “LOW ”?

Y

Comp relay is OK?

Y

N

Y

(Page. 41)

Check it after 5 minutes

Freezer sensor is

OK?

Y

Main PCB temperature

detector is OK?

Y

Check wiring

Reference 2

(Page. 38)

N

Replace sensor

N

Check detector &
replace PCB

Connector CON 8, 10

N

contects are OK?

Y

N

Check connector

Comp ass ’y is OK?

Y

Replace comp

Check wires connection

Samsung Electronics 29

3) No defrosting

Precautions

1. Even though both F·R-defrost sensors short-circuit, normal operation continues without
defrosting.(Refer to self-diagnosis function)

2. Even though the temperature fuse is off, there is no heating but defrosting natural
temperature increase comp off-time takes longer.

3. Even though both F·R-defrost sensor are open, heating does not end and comp-off
maintains with temperature fuse short-circuited.(Refer to self-diagnosis function)

Start

Y

A

R Defrost H #14
F Defrost H #15

R Defrost H #18
F Defrost H #19

R Defrost H RY01
F Defrost H RY09

Does defrosting

start if the forced defrost

key is pressed?

Y

Is power supplied to

defrost heater?

N

Are MICOM pin 14, 15

“HIGH”?

Y

Are IC 06 pin 17, 18

“LOW”?

Y

Defrost heater

relay is OK?

Reference 2

(Page. 38)

Connector CON C8, 09, 10

Evaparator temp. fuse

short-circuited?

Defrost P-cord short-

Y

are OK?

Y

Y

circuited?

N

N

Reference7
(Page. 41)
Measure resistance
of defrost sensor

N

N

N

N

N

N

Does the defrost-sensor

register –5˚C?

Y

Forced starting

Replace MICOM & PCB

Replace IC06

Replace relay

Replace CON

Replace temperature fuse

Replace EVAP ass’y

Check wire connection

30 Samsung Electronics

A

temperature is over than the finish

Reference 7 (Page. 41)
Measure defrost-sensor
resistance

Reference 7 (Page. 41)
Measure defrost-sensor
resistance

Return to normal?

N

Defrost sensor

temperature?

Y

Micom pins 58, 61

voltage is over than the finish

temperature?

Y

Replace MICOM & PCB

Y

Normal

N

Replace the relative sensor

N

Replace temp. detector & PCB

Samsung Electronics 31

5) Fan-motor does not run

Precautions

1. Compressor operates but fan does not run(F·R doors open)

2. Check door close

Start

N

Replace Micom&PCB

N

Replace ICO7

N

Replace RY04, O7

N

Connect connectors

Does compressor run?

Y

Is alarm lit up?

Y

Are Micom pins 13, 17

low?

Y

Are IC07 pins 13, 17

low?

Y

RY04, 07 are OK?

Y

CON 9, 10 connections

are OK?

Y

N

Forced operation

N

Reference 6

Press the alarm key

N

Does alarm ring when

door is open?

Y

Are Micom pins 7, 8

Y

low?

N

Are door S/W defector

Replace Micom, PCB

N

OK?

Repair door S/W
detector & replace

Y

PCB

Check wiring

N

Replace Fan motor

Fan motor are OK?

Y

Check wire connection

32 Samsung Electronics

5) Fan motor in the refrigeration room does not work

Precautions

1. Fan-motor operates with 2 modes.(Static or Rotation)

2. Fan-motor rotates for 30 seconds after one second of door open.

Start

Door open

Replace Micom & PCB

Replace IC07

Repair RY03

Connect connectors

Rotates after 1sec

Y

of door open

N

N

Does it stop if door
continues to open?

N

N

N

N

Is Micom pin 18

“HIGH”

?

Y

Is Micom pin 12

“LOW”

?

Y

RY03 is OK?

Y

CON09 connection

Y

Normal

is OK?

Y

N

Motor L/W is OK?

Check L/W

N

Y

Motor is OK?

Replace Motor

Y

Check parts location

Samsung Electronics 33

6) Lamp Inspection

Note

1. When replacing Sub-PCB, power should be turned off, because Sub-PCB receives AC POWER
INPUT and converts that to 1.5 X AC POWER INPUT.

2. It is impossible to check lamp with normal voltage tester, because lamp voltage is high.

References

1. If new lamp does not turn on, that’s because the protector is activated to prevent peak
voltage when lamp is replaced.
After replacing lamp, wait for 30 seconds after closing the door of refrigerator.

2. Lamp turns off automatically if the door of refrigerator is open for 10sec
If door is closed and opened by the door S/W, lamp turns on again.
If that carries out over twice, protector is activated and lamp maintains off.

3. If there is water in door S/W, lamp close not turn or off because Micom can not receive door
open/close signal. Door S/W should be checked.

4. The connection between Main-PCB and Sub-PCB, Sub-PCB output and cabinet L/W,
cabinet L/W and lamp are done by connector. If there is table with lamp check connector
and lamp.

5. Freezer lamp is controlled by main PCB.

34 Samsung Electronics

① Lamp in the refrigeration room does not light up

Start

Is lamp connected

to connector(pin4)?

Y

Is the

filament coil of lamp short

or faulty?

Y

Is there

water in door S/W or connector

well connected?

Y

Is main

PCB connected to Sub-PCB

connector?

Y

Sub-PCB fuse is OK?

Y

Check connector and door S/W.
Replace Sub-PCB

N

Connect connector,
Faulty connection

Faulty lamp, Replace it

N

Repair, Replace door S/W

N

Connect connector,
Faulty Connection

N

Replace Sub-PCB fuse

②Lamp in the freezer does not light up

Start

Is lamp connected

to connector?

Lamp filament

is OK?

Y

Is there rated votage

on lamp connector?

N

Is there water in

door S/W or connector well

connected?

N

Connect connector,
Faulty connection

N

Replace lamp(Filament short)

Y

Replace lamp

N

Repair, Replace door S/W

Check connector, door S/W and
lamp Normal

Samsung Electronics 35