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Info Center

Refrigerator Info Center Training

 

21

  

Circuit Descriptions

CirCUiT DesCripTions

1-13. Communication circuit and connection L/Wire between main PCB and display PCB

The following communication circuit is used for exchanging information between the main MICOM of the Main PCB and the
dedicated MICOM of the LCD Display PCB. 
A bi-directional lead wire assembly between the two boards is required for the display to function properly.

Poor communication occurs if a continuous information exchange fail to continue for more than 2 minutes between main
MICOM of main PCB and LCD dedicated MICOM for LCD control of display PCB. 

 

EXPLANATION FOR MICOM CIRCUIT 

- 34 -

Main MICOM

LCD(LED) dedicated MICOM

DC 12V

GND

Transmission (error status)

Reception (notch status)

Main PCB

L/Wire FD/H(4-wires)

Display PCB

CIRCuIT dESCRIPTIONS

Содержание LSC27990ST

Страница 1: ...LG TRAINING MANUAL LSC27990ST Refrigerator Info Center Fall 2007 LG TRAINING MANUAL ...

Страница 2: ...hassis the reading must be infinite Any other abnormality that exists must be corrected before the receiver is returned to the customer Electrostatically Sensitive Devices Some semiconductor solid state devices can be damaged easily by static electricity Such components commonly are called Electrostatically Sensi tive ES Devices Examples of typical ES devices are integrated circuits and some field...

Страница 3: ... Refrigerator Info Center Training 3 Contents Table of Contents OVERVIEW 5 Introduction 5 Topics Discussed in this manual 5 Model Number 5 Operation 6 Microcontroller 15 TRoubleshooting 20 Circuit Descriptions 22 ...

Страница 4: ... 4 ...

Страница 5: ...on When your refrigerator is first installed allow it to stabilize at normal operating temperatures 2 3 hours prior to filling it with fresh or frozen foods If operation is interrupted wait 5 minutes before restarting About defective pixels This LCD display contains hundreds of thousands of individual pixels LCD displays typically contain a small number of pixels that do not function normally Your...

Страница 6: ...right or left button select Use 4 Press the SELECT button 5 Return to the standby screen NOTE The display will indicate Processing IcePlus The indicated set temperature is not the actual temperature within the refrigerator but the target temperature The actual internal temperature can differ especially if the door is opened and warm food was recently stored You can select from Crush Water or Cube ...

Страница 7: ...he amount of water supplied to the ice maker needs to adjusted Contact the service center If ice is not used frequently it may lump together Power failure Water may drip from the refrigerator Take the ice storage bin out and discard all the ice then dry it and place it back After the power is restored the refrigerator defaults to crushed ice The unit is newly installed It takes about 12 hours for ...

Страница 8: ...emperature for 5 days including the current day Reception of weather forecast information received and displayed on the screen may vary depending on your region and the location of the refrigerator Therefore LG does not guarantee and will not be held responsible for accuracy of the weather information Check your zip code in the owner s manual or www ambientdevices com cat device coverage html Weat...

Страница 9: ... down button to select Save Select the advance time using the right or left button NOTE The alarm will go off at the set date and time and the anniversary will be displayed in the screen 1 2 3 4 5 View the anniversary list Press the up or down button to select Anniversary Reminder Press the up or down button to select list You can check the detail menu using the right or left button 1 2 3 4 Date T...

Страница 10: ...wn button to select Save Gourmet Recipes There are 10 classifications of recipes under this menu 1 Use the up or down button to select the type of recipe 2 Use the right or left button to select the specific recipe image 3 With MORE highlighted press the Select button to view the recipe Filter Reset You can select from Filter reset Door alarm Dispenser light Manual and Service Call functions Filte...

Страница 11: ... button to select the Owner s Manual 3 Use the right or left to select from the topics 4 Press the select button to open the topic 5 Use the right or left button to select the detail menu 6 Press the down button to select list You can select from Key Guide Tem Adjustment Child Lock Weather Forecast Proper Food Storage Fridge Maintenance Guide Freezer Maintenance Guide or Elimination of Odor functi...

Страница 12: ...eft button to select the Use or Not to Use 1 If Use is selected use the down button to access the time setting 2 Use the right or left to select how long the screen will remain lit 1 3 5 minuets 3 Use the down button to select Save NOTE When you select the Photo the pictures saved in the photo album will be shown in slideshow When selecting Not in Use the current standby screen is saved as Screen ...

Страница 13: ... Photo Album and then connecting a USB memory stick import is automatically activated 3 After setting up the desired photo from the data read select import Downloading will appear on the screen NOTE The Avatar Display applied to this refrigerator uses O S Windows CE which recognition depends on the kind of USB Memory Stick If USB which was recognized before is not recognized currently Power the un...

Страница 14: ... sounds You will see the letters DEMO on the top left side of the screen with a ding sound To exit the DEMO mode and return to normal operation press the TEMPERATURE and the LOCK button and hold simultaneously for 5 seconds until the Ding sounds again NOTE The refrigerator will default to the NORMAL mode DEMO mode OFF if the power fails LCD Check Mode Communication Data Check Mode Press MENU and i...

Страница 15: ...cartridge on the dispenser 2 Water filter needs replacement about every six months 3 You will see a reminder pop up window in the LCD screen 2 weeks before 1 week before due date to replace the filter to notify you that the filter needs to be replaced 4 If you want to reset the filter use the Menu Refrigerator Filter Reset menu Filter condition display function Dispenser use selection You can sele...

Страница 16: ...ate until the 7 minute delay has passed 10 The freezer fan motor runs at high speed during the ICE PLUS cycle OptiFresh Function 1 The OptiFresh bin is positioned at the bottom of the refrigerator compartment and has a separate temperature control to allow perfect storage of fruits and vegetables 2 OptiFresh comprises of OptiFresh sensor at the rear of OptiFresh and a damper between OptiFresh and ...

Страница 17: ...ration manual frost defrost buzzer 1 The buzzer sounds briefly when the test button on the main PCB is pressed 2 If you select manual operation the buzzer sounds three times for 2 10 second each then it sounds three times for 2 10 second each every thirty seconds until the door is closed 3 If you select manual defrost the buzzer sounds three times for 2 10 second each then it sounds three times fo...

Страница 18: ...he refrigerator room lamp turns off automatically Refrigerator room lamp automatic off Component products such as compressor frost removal heater freezing room fan cooling fan and step motor damper are sequentially started as follows to reduce noise and prevent part damage occurred due to starting of many parts during initial power and self test Sequential operation of components ...

Страница 19: ...gaged it will complete its test cycle and default to normal operation after 2 hours 3 The buttons are disabled while the test mode is in effect 4 When you have finished running test mode unplug the refrigerator to reset it to normal operation 5 If a failure is detected during test mode release the test mode to display the failure code 6 If a failure code is displayed the test mode cannot be starte...

Страница 20: ...or Er dS Abnormal short circuit O Standard RPM O No defrost O 5 Failed defrosting Er dH Defrost circuit open O Standard RPM O O O 6 Abnormal freezing BLDC motor Er FF Open or short circuit or motor defect in BLDC circuit O Off O O O 7 Abnormal cooling BLDC motor Er CF O Standard RPM O O O 8 Abnormal communication Er CO Shorted or open lead wire between main and display PCB O Standard RPM O O O 9 A...

Страница 21: ... of the LCD Display PCB A bi directional lead wire assembly between the two boards is required for the display to function properly Poor communication occurs if a continuous information exchange fail to continue for more than 2 minutes between main MICOM of main PCB and LCD dedicated MICOM for LCD control of display PCB EXPLANATION FOR MICOM CIRCUIT Main MICOM LCD LED dedicated MICOM DC 12V GND Tr...

Страница 22: ...in of error u Resistance of the cold storage sensor 1 and 2 shall be measured with a digital tester after separating CON8 of the PWB ASSEMBLY and the MAIN part u Resistance of the freezing sensor shall be measured with a digital tester after separating CON7 of the PWB ASSEMBLY and the MAIN part EXPLANATION FOR MICOM CIRCUIT 35 Measuring Temperature C Freezing Sensor Refrigerator sensor 1 2 Defrost...

Страница 23: ...the voltages to allow the current to dissipate VOLTAGE CHART Power circuit 1 Explanation for PWB circuit 1 1 Power circuit The power circuit includes a Switched Mode Power Supply SMPS It consists of a rectifier BD1 and CE1 converting AC to DC a switch IC2 switching the DC voltage a transformer and a feedback circuit IC3 and IC4 Caution Since high voltage 160 Vdc is maintained at the power terminal...

Страница 24: ...erate LOAD DRIVING CIRCUIT The fan operates at the regular speed even if the door of the refrigerator or freezer is opened When the doors are closed the fan reverts to its original speed A B C and D of door switch for the freezer or refrigerator are connected to the door open sensing circuit in parallel toward both ends of switch to determine door open at MICOM In the TEST mode the fan will stop i...

Страница 25: ...90TT 24 Status ON Within 1 V OFF 12 V 1 5 Dispenser operation circuit 1 GR G277STSA LSC27990TT 1 Check load driving status EXPLANATION FOR MICOM CIRCUIT Type of Load GEARED MOTOR SOLENOID CUBE PILOT VALVE WATER VALVE SOLENOID DISPENSER LOAD DRIVE SCHEMATIC DISPENSER CIRCUIT LOAD DRIVE SCHEMATIC DISPENSER CIRCUIT ...

Страница 26: ...respond properly If either switch fails the light will not come on EXPLANATION FOR MICOM CIRCUIT Closing 5 V A B C D Switch at both ends are at Off status Opening 0 V A B C D Switch at both ends are at On status Measuring part IC1 MICOM No 44 45 45 46 47 48 Pin Door of Freezer and Refrigerator LOAD DRIVE STATUS LEVER SWITCH CIRCUIT DOOR OPEN CIRCUIT Since door switches A and B are interconnected i...

Страница 27: ...efrigerator Option designation circuit model separation function The circuits shown above vary according to which features are included on your particular model 1 8 Switch entry circuit The following circuits are sensing signal form the damper motor reed switch for testing and diagnosing the refrigerator 1 GR G277STSA LSC27990TT 1 9 Option designation circuit model separation function 1 GR G277STS...

Страница 28: ...N FOR MICOM CIRCUIT 29 INA INB A B A B CCW Reverse rotation Positive rotation CW Stepping motor operation circuit The motor is driven by magnetism formed in the areas of the coils and the stator Rotation begins when a HIGH signal is applied to MICOM Pin 33 of IC10 TA7774F This causes an output of HIGH and LOW signals on MICOM pins 34 and 35 Explanation The stepping motor is driven by sending signa...

Страница 29: ...ator 1 GR G277STSA LSC27990TT u Temperature compensation table by adjustment value difference value against current temperature Ex If you change compensation resistance at a refrigerator RCR1 from 10 kΩ current resistance to 18 kΩ modified resistance the temperature at the refrigerator will increase by 1 C 1 8 F Temperature compensation at refrigerator Temperature compensation at freezer Freezer R...

Страница 30: ... 0 9 F 0 9 F 1 8 F 2 7 F 3 6 F 4 5 F 5 4 F 6 3 F 7 2 F Down Down change Up Up Up Up Up Up Up Up 1 5 C 1 C 0 5 C No 0 5 C 1 C 1 5 C 2 C 2 5 C 3 C 3 5 C 5 6 kΩ 2 7 F 1 8 F 0 9 F 0 9 F 1 8 F 2 7 F 3 6 F 4 5 F 5 4 F 6 3 F Down Down Down change Up Up Up Up Up Up Up 2 C 1 5 C 1 C 0 5 No 0 5 C 1 C 1 5 C 2 C 2 5 C 3 C 8 2 kΩ 3 6 F 2 7 F 1 8 F 0 9 F 0 9 F 1 8 F 2 7 F 3 6 F 4 5 F 5 4 F Refrigerator Down Dow...

Страница 31: ... for compensation by changing jumpers at locations JCR1 JCR4 EXPLANATION FOR MICOM CIRCUIT 33 Compensation Compensation for too warm for too cold Temperature compensation value Remarks JCR3 JCR4 JCR1 JCR2 at refrigerator 0 C In shipment from factory CUT 1 C 1 8 F CUT 1 C 1 8 F CUT 1 C 1 8 F CUT 1 C 1 8 F CUT CUT 2 C 3 6 F CUT CUT 2 C 3 6 F CUT CUT 0 C 0 F CUT CUT 0 C 0 F CUT CUT 0 C 0 F CUT CUT 0 ...

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Страница 34: ...2007 Info Center Refrigerator Training ...

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