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6 – 1

SJ431NSL

Service Manual

 

CHAPTER 6. 

FAILURE DIAGNOSIS

[1] OUTLINE OF CONTROL

1. ON/OFF Control of Compressor

When the plug of refrigerator is connected, the compressor will start automatically and run for approximately 5 minutes. After then, ON/OFF of the
compressor will be controlled depend on the temperature detected by the R-thermistor. During 6 minutes after the compressor stops, it will not start
regardless of the detected temperature by R-thermistor..

2. Defrosting

Microcomputer  calculates  the  appropriate  timing  of  defrosting  and  defrosting  is  made  automatically.  Therefore  no  manual  operation  by  user  is
required. The cycle of defrosting varies depend on the usage condition of the refrigerator. (Maximum time 50 hours, minimum time 4 hours)

3. Thermistor

Thermistors  are  installed  in  2  places;  in  the  refrigerator  compartment  and  close  to  the
Evaporator. (R-thermistor and Def-thermistor)

It is not installed in the freezer compartment.

R-thermistor reads the temperature in the refrigerator compartment and controls ON/OFF
of compressor.

Def-thermistor detects the temperature around the evaporator and shows the progress of
defrosting.

[2] CHECK MODE OF DEFROST  HEATER (Forced Defrosting)

The operation of the defrost heater can be checked by starting it.

In case the failure of defrosting is suspected, this is an effective inspection method.

1. Starting Method

At the power OFF condition.

1) Keep the door of the refrigerator compartment open.

2) Set the Temp. Control Knob in the refrigerator compartment to the following position.

220-240V models: Center

110-127V models: Max

3) Keep the door open and supply power source.

2. Normal Operation

1) Approximately 3 seconds after power supply, the relay on the PWB will be turned ON and the defrost heater will be electrified for 5 seconds.

2) After 5 seconds, if the temperature of Def-thermistor reaches high enough (over 10°C) and judged as defrosting completion, the compressor runs

for 5 minutes and then returns to the normal control.

On the other hand, if the temperature of Def-thermistor is still low (under 10°C), the defrost heater will be electrified until the temperature of Def-
thermistor reaches the specified temperature or higher.

After completion of electrification, the compressor runs for 5 minutes and then returns to the normal control.

*

In the case that any abnormality in Door Switch, Volume, R-thermistor or Def-thermistor, or the Temp. Control Knob is not in the position corre-
sponding to the value of the rating voltage settled to the PWB itself, this mode will not be entered nor the defrost heater is electrified.

Def-thermistor

Evaporator

Defrost heater

R-thermistor

PWB

Compressor

(Center)

 !"#$% &'$( &#$) &'$* &#$+ &'$, &#-( &#-) 

Summary of Contents for SJ-A20S-SL

Page 1: ... 4 CHAPTER 4 LIST OF ELECTRICAL PARTS CHAPTER 5 WIRING DIAGRAM 1 WIRING DIAGRAM 5 1 2 ELECTRIC ACCESSORIES LAYOUT 5 2 CHAPTER 6 FAILURE DIAGNOSIS 1 OUTLINE OF CONTROL 6 1 3 RE SETTING OF MICROCOMPUTER AT POWER FAILURE 6 2 4 DIAGNOSIS METHOD OF FAILURE 6 2 5 CONVERSION TABLE 6 3 6 CIRCUIT DIAGRAM OF MAIN PWB 6 4 CHAPTER 7 FUNCTIONS 1 ADJUSTABLE TEMPERATURE CONTROL 7 1 CHAPTER 8 ASSEMBLI NG PROCEDUR...

Page 2: ...elf plastic 1 1 V shelf ass y glass 1 Vegetable case Egg pocket Small pocket Door pocket B Bottle pocket Door pocket 1 1 Deodorizing unit Items Type No frost freezer Interior lamp Evaporating pan 1 Rate storage volume Rated volume Temperature control Automatic Adjustable Yes 1 1 1 2 Door Heater system Automatic Automatic 1 1 Twin ice cube maker 1 1 1 1 1 Honeycomb type SJ A20S B21S A24S B25S A28S ...

Page 3: ... Vegetable case Egg pocket Egg tray Small pocket 1 2 Door pocket B Bottle pocket Door pocket 1 Honeycomb type 1 1 1 1 2 Door Automatic 2 Temperature control Automatic 1 Twin ice cube maker 1 Deodorizing unit Items Type No frost freezer Interior lamp Evaporating pan Rated storage volume Rated volume 1 Heater system 1 1 Automatic Adjustable Yes 1 1 1 SJ A31S A34S SJ A31S SJ A34S Rated voltage V Rate...

Page 4: ...ass SJ A28S B27S A31S 2 pcs SJ A34S 3 pcs 9 Vegetable shelf 10 Vegetable crisper Vegetable case 11 Adjustable foot Adjustable leg 12 Magnetic door seal Door packing 13 Door pocket 16 Light switch 15 Egg pocket SJ A20S B21S A24S B25S 2 pockets SJ A28S B27S A31S A34S 3 pockets 17 Small pocket right Small pocket 18 Small pocket left Door pocket B 19 Bottle pocket SJ A24S B25S A28S B27S A31S 1 pocket ...

Page 5: ...r Def thermistor F temp control knob R temp control knob Evaporator Defrost heater Deodorizing unit R thermistor PWB L ass y Running capacitor Lamp Compressor Starting relay Protector Evaporating pan Mark Cold air flow Fuse ass y ...

Page 6: ...IMENTIONS 1 OUTER DIMENTIONS AND CLEARANCE 1 SJ A20S B21S 2 SJ A24S B25S Unit mm 9 34 4 610 628 5 1085 545 1145 365 970 545 443 5 757 5 1253 Unit mm 9 34 4 610 628 5 1085 545 1145 365 970 545 443 5 893 5 1389 60 60 60 60 60 60 ...

Page 7: ...3 2 3 SJ A28S B27S Unit mm 9 34 4 610 628 5 1085 545 1145 365 970 545 515 5 923 5 1491 60 60 60 4 SJ A31S 600 600 541 5 986 5 34 4 1065 1161 1221 405 631 1580 9 649 5 ...

Page 8: ...34 4 631 1161 600 1221 405 1065 1700 9 649 5 2 INNER DIMENTIONS 1 SJ A20S B21S 380 390 253 321 45 146 149 300 67 107 67 196 55 43 391 38 33 138 417 417 363 208 371 366 366 137 208 204 154 103 250 143 107 66 120 80 211 292 340 Unit mm ...

Page 9: ...67 137 208 253 271 214 187 434 204 154 103 250 143 107 66 120 80 91 211 292 68 340 417 292 154 86 3 SJ A28S B27S 391 38 33 55 43 138 390 169 417 417 417 363 208 137 208 253 271 214 45 103 250 143 107 66 66 202 464 144 123 184 196 120 80 91 180 68 30 107 67 371 366 67 366 67 366 292 211 Unit mm 292 254 204 154 ...

Page 10: ...7 66 66 231 254 204 154 217 120 80 91 180 68 237 30 107 67 430 430 67 416 67 416 231 312 312 430 38 33 55 43 138 445 480 472 472 411 217 152 217 5 3 3 2 8 2 147 170 160 650 155 45 111 380 92 107 66 66 231 254 204 154 217 120 80 91 91 180 68 237 59 30 30 107 67 430 430 67 416 67 416 231 312 150 155 237 155 312 472 312 170 ...

Page 11: ... B25S A28S B27S A31S A34S FL0845 ST FL1152 SZ FL1257 SW 220 240V 50Hz 220 240V 50Hz Cooling capacity 106 W 50Hz Main coil 23 8 Ω Aux coil 29 7 Ω at 75 C Cooling capacity 136 W 50Hz Main coil 23 8 Ω Aux coil 42 4 Ω at 75 C Cooling capacity 170 W 50Hz Main coil 18 4 Ω Aux coil 31 5 Ω at 75 C Starting Relay PEN0SBT 50 60 Hz 22 4 4Ω at 25 C Overload Relay Protector A20S B21S A24S B25S A28S B27S A31S A...

Page 12: ...26LVSL CHAPTER 5 WIRING DIAGRAM 1 WIRING DIAGRAM Be sure to replace the electrical parts with specified ones for maintaining the safety and performance of the set BL STARTING RELAY COMPRESSOR RUNNING CAPACITOR ...

Page 13: ...UT F LOUVER ASS Y FAN MOTOR FM LEAD EV COVER FUSE DEF THERMISTOR DEF HEATER R CBOX K PWB LAMP R THERMISTOR DOOR SWITCH TERMINAL COVER COMPRESSOR PROTECTOR STARTING RELAY CABINET HARNESS FL ASS Y RELAY WIRE ASS Y BOTTOM ANGLE RUN CAP ...

Page 14: ...d free solder Sn Ag Cu is higher and has poorer wettability flow to prevent damage to the land of the PWB extreme care should be taken not to leave the bit in contact with the PWB for an extended period of time Remove the bit as soon as a good flow is achieved The high content of tin in lead free solder will cause premature corrosion of the bit To reduce wear on the bit reduce the temperature or t...

Page 15: ...ater can be checked by starting it In case the failure of defrosting is suspected this is an effective inspection method 1 Starting Method At the power OFF condition 1 Keep the door of the refrigerator compartment open 2 Set the Temp Control Knob in the refrigerator compartment to the following position 220 240V models Center 110 127V models Max 3 Keep the door open and supply power source 2 Norma...

Page 16: ... Be sure to detach the connector CN1 before measuring the resistance between the both ends of the fuse by the tester Next measure the resistance value between the both leads of the varistor 4 Check whether the temperature resistance value shown by R thermistor is correct or not Refer to the table below Detach the connector CN3 on the PWB and measure the resistance value between 1 and 2 pins 5 Chec...

Page 17: ...istance Value kΩ Temperature C Resistance Value kΩ 25 26 1 11 11 49 3 5 5 24 24 54 10 10 88 4 5 23 23 23 08 9 10 3 5 4 98 22 21 72 8 9 75 6 4 74 21 20 46 7 9 24 7 4 52 20 19 27 6 8 76 8 4 3 19 18 16 5 8 3 9 4 1 18 17 13 4 7 87 10 3 91 17 16 16 3 7 47 11 3 73 16 15 25 2 7 09 12 3 56 15 14 4 1 6 74 13 3 4 14 13 6 0 6 4 14 3 24 13 12 85 1 6 08 15 3 1 12 12 15 2 5 78 ...

Page 18: ...6 4 6 CIRCUIT DIAGRAM OF MAIN PWB ...

Page 19: ...ing toward MIN With the FREEZER TEMP CONTROL set to MAX there will be less cold air directed to the refrigerator compartment and the refrigera tor compartment may not become cold enough 2 Reference value of temperature The values tables above refer to the measurement carried out center area and 1 3 of overall height from the bottom at each of the refrigerator and the freezer after the machine has ...

Page 20: ...d air controlling the compressor the fan running time high cold power controlling the compressor the fan running time Freezer Temp Control Knob The FREEZER TEMP CONTROL regulates the quantity of cold air to the freezer MAX setting directs more cold air to the freezer compartment making the freezer compartment colder MIN setting directs less cold air to the freezer compartment making the freezer co...

Page 21: ...d EV cover Fan motor Motor cushion Fan motor holder a Propeller fan 90 Fan clamp Slit area Figure A 1 Fan motor holder b U sealer handle U sealer handle Fan motor holder b Lead EV cover Fan motor Fan clamp Propeller fan 90 Detail of D Propeller fan 90 Fan clamp Fan motor Motor cushion Motor cushion Fan motor holder b Fan motor holder a Note 1 Assemble so that terminal of Fan motor does not deform ...

Page 22: ... the 6P connector of Lead EV cover Figure A 7 7 After wiring at rear of EV cover take out lead wire from square hole to front and fix with L band c Then stick EVC sealer b to lead wire Fuse ass y L band c Glass cloth tape W25xL50 Figure A 5 Note Fan motor ass y Tapping screw Def thermistor W25xL50 Glass cloth tape Stick Al tape from here Aluminum tape W39xL135 L band c SEC D D SCALE 2 1 FUSE BLACK...

Page 23: ... holder a Fan motor holder b F louver F control knob Fan motor holder a Fan motor holder b EV cover NO CLEARANCE Double face tape W15xL45 m m 5 3 n a h t e r o m m m 5 3 n a h t e r o m Figure A 8 Lead EV cover EV cover F louver F control knob arm B F louver arm A F control knob F louver F control knob SEC B B SEC C C Attachment specification of the F control knob arm B The F control knob is inser...

Page 24: ...ng screw Slit area BROWN RED Lead EV cover Figure A 1 Fan clamp slit slit SEC C C Fan motor holder a U sealer handle Fan motor holder a U sealer handle Fan motor 1 Slit of each Fan Clamp and propeller fan 100 should not be at same position 2 Fan clamp should be inserted virtically to the end of boss 3 Propeller fan should not be taken out from shaft when pulled by 2 kgf 1 Assemble so that terminal...

Page 25: ...he 6P connector of Lead EV cover Figure A 7 7 After wiring at rear of EV cover take out lead wire from square hole to front and fix with L band c Then stick EVC sealer b to lead wire Fuse ass y L band c Glass cloth tape W25xL50 Figure A 5 Note SCALE 2 1 FUSE BLACK BLUE WHITE BLACK BLUE WHITE Pins should be inserted surely and check by pulling it PL Process Note Figure A 7 Figure A 6 FAN MOTOR DEF ...

Page 26: ... holder a Fan motor holder b F louver F control knob Fan motor holder a Fan motor holder b EV cover NO CLEARANCE Double face tape W15xL45 m m 5 3 n a h t e r o m m m 5 3 n a h t e r o m Figure A 8 Lead EV cover EV cover F louver F control knob arm B F louver arm A F control knob F louver F control knob SEC B B SEC C C Attachment specification of the F control knob arm B The F control knob is inser...

Page 27: ...ss y with PWB holder A and then assemble the PWB holder A with PWB holder B 4 Stick the R control AL on PWB holder A B ass y Lamp R C Box cover Control label R Control knob Figure A 10 Lead R Thermistor White wire Lead R C Box Lead R C Box PWB holder B PWB holder A Lead sealer Figure A 11 PWB holder A R control AL PWB holder B ...

Page 28: ... the PWB ass y with R C Box cover And place the R Thermistor on the groove of R C Box cover 8 Insert Lead R C Box to Lamp 9 Insert R Control knob to R C Box cover 10 Stick Control Label on R C Box cover R C Box cover Knob sealer R C Box cover Knob joint Figure A 12 PWB holder R Thermistor R C Box cover Lamp Figure A 13 Control label R Control knob Figure A 14 ...

Page 29: ...8 9 4 HOW TO REPLACE THE LAMP 1 Remove the Light cover 2 Remove the 2 screw and pull the Lamp out 3 Insert the new Lamp to the connector and fix with 2 screws 4 Set the Light cover Screw ...

Page 30: ... take care not to hurt yourself by fin of Evaporator 2 Replacement of Def heater 1 Remove the aluminium tape on Heater support to take it off from the food liner 2 Raise the protrusion part of Heater support Then remove Heater cover 3 Open Def heater fixed part of Heater support al to the right and left then remove Def heater ass y Evaporator Food liner convex part Figure A 15 Food liner convex pa...

Page 31: ...gure A 16 2 Correct the deformed fin NOTE 1 When installing Evaporator take care not to deform signifi cantly and break the pipes 2 Take care not to damage the lead wires and hurt yourself by the fin of Evaporator 3 You shouldn t touch Defrost Heater with your bare hand you should were pure gloves 4 You should wipe that with alcohol When you touch Defrost heater with your bare hand Heater support ...

Page 32: ...ing on the iron pipe end 20mm by the sandpaper Put the flux on silver brazing rod and dry the flux by the flame of the torch and then start brazing Remove the flux completely by the wire brush and wipe off by the cloth after brazing Leakage inspection should be done when compressor is running After removing flux paint the black enamel paint on the brazing part Copper back condenser is used in some...

Page 33: ...ipe Mark shows Ag brazing points Mark shows Cu brazing points Charge pipe to Dryer Dryer connector to Dryer Hot pipe to Dryer connector Pinch Point Dryer to Capillary tube Compressor s discharge pipe Suction butyl to Discharge P connector Charge pipe L to Compressor s process tube Back condenser to Hot pipe D P butyl Discharge P connector to Back condenser Pinch point S P connector to Compressor s...

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