Lg lac 6700 r service manual

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1-1 CONTENTS SECTION 1 SUMMARY SERVICING PRECAUTIONS ........................................................................\ ..................................................................1-2 ESD PRECAUTIONS ........................................................................\ ....................................................... ........................1-3 SPECIFICATIONS ........................................................................\ .....................................................................................1-4 SECTION 2 ELECTRICAL ELECTRICAL TROUBLESHOOTING GUIDE & WAVEFORMS ........................................................................\ .....2-1 1. MAIN, FRONT & TUNER PART.......................................................................\ .............................. ...........................2-1 2. CD PART TROUBLESHOOTING ........................................................................\ .............................. .......................2-4 3. USB PART TROUBLESHOOTING ........................................................................\ ............................. ......................2-7 - WAVEFORMS ........................................................................\ ....................................................... ...............................2-9 INTERNAL BLOCK DIAGRAM OF ICs ........................................................................\ ..............................................2-12 1. IC518, IC701 & IC702 (S4580) ........................................................................\ ........................ ...............................2-12 2. IC301 (HA13173AH) ........................................................................\ ................................... .....................................2-12 3. IC302 (BA00CCOWFP) ........................................................................\ .................................. .................................2-14 4. IC401 (µPD78F1164) ........................................................................\ .................................. .....................................2-14 5. IC601 (TDA7419) ........................................................................\ ..................................... ........................................2-17 6. IC602 (NJM2706-DMP24) ........................................................................\ ............................... ................................2-19 7. IC801 (TB2904HQ) ........................................................................\ .................................... ......................................2-20 8. IC901 (LD3811) ........................................................................\ ...................................... ..........................................2-21 BLOCK DIAGRAM ........................................................................\ .................................................................................2-23 CIRCUIT DIAGRAMS ........................................................................\ ....................................................... ......................2-25 1. MAIN CIRCUIT DIAGRAM ........................................................................\ ................................. .............................2-25 2. CDP 1 CIRCUIT DIAGRAM ........................................................................\ ................................. ...........................2-27 3. CDP 2 CIRCUIT DIAGRAM ........................................................................\ ................................. ...........................2-29 4. FRONT CIRCUIT DIAGRAM ........................................................................\ ................................. .........................2-31 5. USB CIRCUIT DIAGRAM ........................................................................\ .................................. ..............................2-33 6. LCD LIGHTING CIRCUIT DIAGRAM ........................................................................\ ......................... ....................2-34 PRINTED CIRCUIT DIAGRAMS ........................................................................\ ..........................................................2-35 1. MAIN P.C.BOARD ........................................................................\ ...................................... ......................................2-35 2. CDP P.C.BOARD ........................................................................\ ........................................ .....................................2-39 3. FRONT P.C.BOARD ........................................................................\ ...................................... ..................................2-40 4. USB P.C.BOARD........................................................................\ ....................................... .......................................2-41 5. LCD LIGHTING P.C.BOARD ........................................................................\ .............................. .............................2-41 SECTION 3 EXPLODED VIEWS 1. CABINET AND MAIN FRAME SECTION ........................................................................\ ....................... .................3-1 2. MECHANISM(PICK-UP) SECTION ........................................................................\ .......................... ........................3-3 SECTION 4 REPLACEMENT PARTS LIST .............................................................4-1 Copyright © 2007 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only

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1-2 1. Always disconnect the power source before: 1) Removing or reinstalling any component, circuit board, module or any\ other instrument assembly. 2) Disconnecting or reconnecting any instrument electrical plug or othe\ r electrical connection. 3) Connecting a test substitute in parallel with an electrolytic capaci\ tor in the instrument. CAUTION : A wrong part substitution or incorrect polarity installation of electrolyt\ ic capacitors may result in an explosion hazard. 2. Do not defeat any plug/socket B+ voltage interlocks with which instrumen\ ts covered by this service manual might be equipped. 3. Do not apply power to this instrument and or any of its electrical assem\ blies unless all solid-state device heat sinks are correctly installed. 4. Always connect a test instruments ground lead to the instrument chassis ground before connecting the test instrument positive lead. Always remove the test instrument ground lead last. 1) The service precautions are indicated or printed on the cabinet, chassis\ or components. When servicing, follow the printed or indicated service precautions and service material\ s. 2) The Components used in the unit have a specified conflammability and\ dielectric strength. When replacing any components, use components which have the same ratings. Components m\ arked in the circuit diagram are important for safety or for the characteristics of the unit. Always replace with the exact components. 3) An insulation tube or tape is sometimes used and some components are rai\ sed above the printed writing board for safety. The internal wiring is sometimes clamped to prevent contact with heating\ components. Install them as they were. 4) After servicing always check that the removed screws, components and\ wiring have been installed correctly and that the portion around the service part has not been damaged. Furth\ er check the insulation between the blades of attachment plug and accessible conductive parts. SERVICING PRECAUTIONS SECTION 1 SUMMARY Copyright © 2007 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only