Samsung b25, S25, B24, S26, S27 Troubleshooting

10. Troubleshooting

10-1) When Power is not On,

1. Before repair, check whether POWER CORD is normally connected.

2. Check using the following information.

Pre-Check

Snapping of 220 V AC FUSE ?

START

Replacement of FUSE

Connection of ends of

POWER CORD

DC-TRANS

1st power

is supplied?

Check of wire assembly

connection

DC-TRANS 2nd

power is supplied?

Replacement of

DC-TRANS

Snapping of FUSE on

MAIN PCB?

Replacement of FUSE

(AC 220 V 500 mA)

DC 5V on MAIN PCB

is coming out?

Repair Power part on PCB

(Replacement of REG 7805)

Voltage measurement

of REG 7085 OUT end

DC 12V on MAIN PCB

is coming out?

Repair Power part on PCB

(Replacement of REG 7812)

Wire connection of

PANEL PCB is normal?

Repair by Wire Connection

(Refer to 1)

LEAD WIRE CABI, DOOR

(Connect at hinge-upp)

PANEL PCB is normal?

Replacement of PANEL

PCB

RESET IC (ICO2) OUTLET

is DC 5V?

Replacement of RESET IC

NORMAL

Y

N

N

Y

N

Y

Y

N

N

Y

N

Y

N

Y

N

Y

N

Y

37

Refer to 4

10-2) When Compressor and Cooling FAN MOTOR does not operate,

1. Compressor does not operate at the first power supply or after compressor is OFF.

2. During defrosting, compressor does not operate.

3. When Freezer sensor is not connected, low-temperature is sensed and so, compressor does not
operate.

5minutes have passed since

COMP OFF?

START

Check after 5 minutes

Refer to 6

(Forced-operation alarm sounds?)

Replacement of

MICOM and PCB

Replacement of IC03

Compressor operate by

forced-operation?

MICOM #23 is HIGH?

Open and Repair of

Connection

Repair of Sensor and
Replacement of PCB

IC03 #16 is LOW(0V)?

Adjustment of Wire, Repair

of Connection state

COMP RELAY is normal?

Replacement of COMP

RELAY

Refer to 2

Contact state of

CONNECTOR CN70 and

CN71 is normal?

Full insertion of

CONNECTOR

COMP ASSÕY is normal?

Replacement of

COMP ASSÕY

Wire assembly and Connection state

N

Y

Y

N

N

Y

N

Y

Y

N

Y

N

Y

N

Y

Freezer Sensor

is normal?

Temperature

Sensor of MAIN PCB

is normal?

Pre-Check

38

1. When normal refrigeration operation works on the first POWER ON, but troubles with freezing and
refrigerating occur after some time (at defrosting step), there must be something wrong with Defrosting
system and then, check the defrosting system on the basis of this trouble diagnosis.

10-3) When Defrosting does not work,

CRITERIA FOR JUDGEMENT

Information

1. When there are SHORT-type troubles with EVA-SENSOR of F and R, do not charge the defrost-heater and
return to the normal operation after pause. So, if the period of non-operation of the defrost-heater is
accumulated, troubles with freezing and refrigerating may occur.

2. When there is OFF of Thermal-Fuse, a kind of safety gadget, snapping of wire, or troubles with
RELAY on PCB, troubles with freezing and refrigerating may occur because defrosting is caused by the
increase of natural temperature and thus, COMP OFF time becomes longer.

3. When there are OPEN-type troubles with Defrost-Sensor of each F and R, HEATING does not come to
be terminated and Thermal-Fuse, a kind of safety gadget, becomes snapped after some time.
So, since HEATING operation continues to operate and COMP ON does not operate, troubles with freezing
and refrigerating may occur.

On the basis

of self-diagnosis,F, R defrost-

sensor is normal?

START

Replacement of the relevant

SENSOR

Refer to reference no. 3, check of

trouble with load, of this manual

Judge on the basis of reference no. 4

and 8 of this manual

Refer to

7-6) Test function of Main function

Defrost-heater of F and

R-room are normal?

Check of Temperature FUSE,

snappingof heater itself, and

contact state of wire

Temperature of the relevant

defrost-sensor is below

-5 ?

Perform forced-operation for

some time.

Perform concurrent

forced-defroster of F, R-room

Power is supplied to

each defrost-heater?

A

B

N

N

Y

Y

N

Y

N

Y

39

After heating

for some time, COMP ON

comes to operate?

When the temperature of the

defrost-sensor for F and R comes

to be more than +5 and +17 ,

respectively, by heating, stop

HEATING and return to COMP

ON after pause time.

Normal

Repair of Connector terminal

See the LOAD OPERATION

CIRCUIT and reference 2. Check

method of RELAY.

N

Y

A

If not, re-CHECK of the

relevant sensor.

Connector terminal of
MAIN PCB is normal?

Problem with RELAY of the relevant

defrost-heater or with PCB

COMP RELAY/NORMAL CLOSE

Check of terminal contact

Replacement of defective

RELAY or PCB ASSÕY

N

Y

B

40

10-4) Trouble with self-diagnosis

(1) Trouble with ambient thermal-sensor

MAIN-PCB

connector (CN32) is normally

inserted?

START

Repair of connector

contact trouble

Ambient thermal-sensor

port is normal?

Replacement of thermal-

sensor

MICOM PIN#60 voltage

input is normal?

Check of MAIN-PCB cold

lead and short

No trouble with PCB and thermal-sensor.

Re-check of connector

contact trouble.

N

N

Y

Y

N

Y

(2) Trouble with thermal-sensor for refrigerator

Thermal-sensor

port is normal?

START

Replacement of

thermal-sensor

MAIN-PCB connector (CN31)

is normally inserted?

Repair of connector contact

trouble, Re-insertion

Wire-Connection

between MAIN-PCB connector(CN31)

sensors is normal?

Snapping of wire between

connector and sensor,

CHECK and Repair

No trouble with PCB and

thermal-sensor. Re-check of

connector contact trouble.

N

N

Y

Y

N

Check of cold lead, short,

lead Touch

N

Y

MICOM PIN#56 voltage

input is normal?

Y

41

(3) Trouble with defrost-sensor for refrigerator (Bimetal)

MAIN-PCB

connector (CN31) is normally

inserted?

START

Repair of connector (CN31)

contact trouble, Re-insertion

Replacement of

thermal-sensor

Repair of non-insertion of

connector and contact trouble

Defrost-sensor port

is normal?

Connection

between Defrost-sensor and

Connector is normal?

No trouble with PCB and

thermal-sensor.

Re-check of connector contact trouble.

N

N

Y

Y

N

Y

Check of cold lead, short,

lead Touch

MICOM PIN#57

voltage input is normal?

N

Y

(4) Trouble with thermal-sensor for freezer

MAIN-PCB

connector (CN30) is normally

inserted?

START

Repair of connector (CN30)

contact trouble, Re-insertion

Thermal-sensor

port for freezer

is normal?

Replacement of

thermal-sensor

Connection between

sensor of the freezing room and

connector is normal?

Repair of connector contact

trouble, Re-insertion

No trouble with PCB and

thermal-sensor.

Re-check of connector contact trouble.

N

N

Y

Y

N

Check of cold lead,

short, lead Touch

N

Y

MICOM PIN#58 voltage

input is normal?

Y

42

(5) Trouble with defrost-sensor for freezer(Bimetal)

MAIN-PCB

connector (CN30) is normally

inserted?

START

Repair of connector (CN30)

contact trouble, Re-insertion

Defrost-sensor

port for freezer

is normal?

Replacement of

thermal-sensor

Connection

between defrost-sensor and

connector is normal?

Repair of connector contact

trouble, Re-insertion

No trouble with PCB and

thermal-sensor. Re-check of

connector contact trouble.

N

N

Y

Y

N

Check of cold lead,

short, lead Touch

N

Y

MICOM

PIN#59 voltage input

is normal?

Y

43

10-5) When alarm continues to sound,

Information

DOOR OPEN alarm for the Freezer/Refrigerator sound for 10 seconds 2 minutes after the

first DOOR OPEN and then, continues to sound for 10 seconds at 1-minute interval when the
DOOR is in open. (Ding-Dong sounds 10 times)

If water or moisture permeates DOOR S/W, the contact of DOOR S/W comes to be SHORT.
At that case, DOOR is perceived to be in OPEN by MICOM and alarm continues.
When this situation continues for 10 minutes, the inside lamp of the freezer is turned OFF.
The lamp does not come to be ON when the door comes to open actually.

If DOOR S/W is wetted and the contact becomes rotten, the signals indicating DOOR OPEN is
not inputted to MICOM and so, the lamp is in OFF and DOOR OPEN alarm does not sound.

(1) When Ding-Dong sounds continuously,

Any trace of the

permeation of water in

DOOR S/W

START

Replacement of DOOR S/W

Input voltage

at MICOM Pin #48, #49

is changed?

Repair of wire snapping and

trouble with DOOR S/W

MAIN-PCB

connector (CN30, 31) is normally

inserted?

Repair of connector contact

trouble, Re-insertion

No trouble with MAIN PCB

and DOOR S/W

N

N

(On DOOR OPEN/CLOSE)

Y

Y

N

Replacement of DOOR S/W

N

Y

DOOR S/W itself is normal?

Y

44

(2) When ÒPeepÓ continues to sound,

Whether

Forced-Defrost or Forced-Operation

is selected?

START

Cancellation of Forced-Defrost

or Forced-Operation

Buzzer sounds in spite

of re-POWER ON?

MAIN-PCB is normal

Check of Connector

(CN40), lead TOUCH, insertion

of particles, SHORT

N

N

Y

Y

Information

ÒPeepÓ alarm does not sound except the case of Forced-Operation, Forced-Defrost, and finding
of abnormal things during Self-Diagnosis.
On the finding of abnormal things during Self-Diagnosis, the relevant things can be found on
PANEL-DISPLAY. If PANEL-DISPLAY is normal and ÒPeepÓ continues to sound, it is most
likely that Forced-Operation or Forced-Defrost is selected.

(3) When PANEL-DISPLAY does not turn on,

Connector

insertion of Hinge-Upp Cover

is normal?

START

Re-insertion of Connector,

Repair of Contact trouble

MAIN-PCB

connector (CN50) is normally

inserted?

Re-insertion of

MAIN-PCB connector

Connector

insertion at PANEL-DISPENSER

part is normal?

Re-insertion of Connector,

Repair of contact trouble

Replacement of PANEL-DISPLAY

N

N

Y

Y

N

Y

45