LG-LMD6540-cs-sm 电路图 维修手册.pdf

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1、- 1-1 - CONTENTS SECTION 1.GENERAL SERVICING PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 ESD PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 SECTION 2.ELECTRICA

2、L SECTION TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11 SCHEMATIC DIAGRAMS . . . . . . . . . . . .

3、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13 WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27 PRINTED CIRCUIT BOARD DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4、 . . . . . . . 2-29 SECTION 3.DVD PART DVD ELECTRICAL TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 INTERNAL BLOCK DIAGRAM of ICs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7 SCHEMATIC DIAGRAM . . . . . . . . . . .

5、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27 PRINTED CIRCUIT BOARD DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33 SECTION 4. EXPLODED VIEWS CABINET AND MAIN FRAME SECTION . . . . . . . . . . . . . . . . . . . . . . .

6、 . . . . . . . . . . . . . . . . 4-1 TAPE DECK MECHANISM (A/R & A/S : LEFT A/S DECK) . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5 TAPE DECK MECHANISM (A/R & A/S : RIGHT A/R DECK) . . . . . . . . . . . . . . . . . . . . . . . . .4-7 SECTION 5. SPEAKER PART . . . . . . . . . . . . . . . . .

7、 . . . . . . . . . . . . . . . . . . . .5-1 SECTION 6. REPLACEMENT PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1 RadioFans.CN 收音机爱 好者资料库 - 1-2 - SECTION 1. GENERAL SERVICING PRECAUTIONS NOTES REGARDING HANDLING OF THE PICK-UP 1. Notes for transport and storage 1) The pick-up sh

8、ould always be left in its conductive bag until immediately prior to use. 2) The pick-up should never be subjected to external pressure or impact. 2. Repair notes 1) The pick-up incorporates a strong magnet, and so should never be brought close to magnetic materials. 2) The pick-up should always be

9、handled correctly and carefully, taking care to avoid external pressure and impact. If it is subjected to strong pressure or impact, the result may be an operational malfunction and/or damage to the printed-circuit board. 3) Each and every pick-up is already individually adjusted to a high degree of

10、 precision, and for that reason the adjustment point and installation screws should absolutely never be touched. 4) Laser beams may damage the eyes! Absolutely never permit laser beams to enter the eyes! Also NEVER switch ON the power to the laser output part (lens, etc.) of the pick-up if it is dam

11、aged. 5) Cleaning the lens surface If there is dust on the lens surface, the dust should be cleaned away by using an air bush (such as used for camera lens).The lens is held by a delicate spring. When cleaning the lens surface, therefore, a cotton swab should be used, taking care not to distort this

12、. 6) Never attempt to disassemble the pick-up. Spring by excess pressure. If the lens is extremely dirty, apply isopropyl alcohol to the cotton swab. (Do not use any other liquid cleaners, because they will damage the lens.) Take care not to use too much of this alcohol on the swab, and do not allow

13、 the alcohol to get inside the pick-up. Storage in conductive bagDrop impact NEVER look directly at the laser beam, and dont let contact fingers or other exposed skin. Magnet How to hold the pick-up Conductive Sheet Cotton swab Pressure Pressure RadioFans.CN 收音机爱 好者资料库 - 1-3 - NOTES REGARDING COMPAC

14、T DISC PLAYER REPAIRS 1. Preparations 1) Compact disc players incorporate a great many ICs as well as the pick-up (laser diode).These components are sensitive to, and easily affected by, static electricity. If such static electricity is high voltage, components can be damaged, and for that reason co

15、mponents should be handled with care. 2) The pick-up is composed of many optical components and other high-precision components. Care must be taken, therefore, to avoid repair or storage where the temperature of humidity is high, where strong magnet- ism is present, or where there is excessive dust.

16、 2. Notes for repair 1) Before replacing a component part, first disconnect the power supply lead wire from the unit 2) All equipment, measuring instruments and tools must be grounded. 3) The workbench should be covered with a conductive sheet and grounded. When removing the laser pick-up from its c

17、onductive bag, do not place the pick-up on the bag. (This is because there is the possibility of damage by static electricity.) 4) To prevent AC leakage, the metal part of the soldering iron should be grounded. 5) Workers should be grounded by an armband (1M ) 6) Care should be taken not to permit t

18、he laser pick-up to come in contact with clothing, in order to prevent sta- tic electricity changes in the clothing to escape from the armband. 7) The laser beam from the pick-up should NEVER be directly facing the eyes or bare skin. CLEARING MALFUNCTION You can reset your unit to initial status if

19、malfunction occur(button malfunction, display, etc.). Using a pointed good conductor(such as driver), simply short the RESET jump wire on the inside of the volume knob for more than 3 seconds. If you reset your unit, you must reenter all its settings(stations, clock, timer) NOTE: 1.To operate the RE

20、SET jump wire, pull the volume rotary knob and release it. 2. If you wish to operate the RESET jump wire, it is necessary to unplug the power cord. Resistor (1 Mohm) Conductive Sheet Resistor (1 Mohm) Armband RESET jump wire VOLUME VOLUME KNOB DOWN UP RadioFans.CN 收音机爱 好者资料库 - 1-4 - ESD PRECAUTIONS

21、Electrostatically Sensitive Devices (ESD) Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called Electrostatically Sensitive Devices (ESD). Examples of typical ESD devices are integrated circuits and some field-effect transistors and

22、 semiconductor chip components.The following techniques should be used to help reduce the incidence of component damage caused by static electricity. 1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off any electrostatic charge on your body by touc

23、hing a known earth ground. Alternatively, obtain and wear a commercially available discharging wrist strap device, which should be removed for potential shock reasons prior to applying power to the unit under test. 2. After removing an electrical assembly equipped with ESD devices, place the assembl

24、y on a conductive sur- face such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly. 3. Use only a grounded-tip soldering iron to solder or unsolder ESD devices. 4. Use only an anti-static solder removal device. Some solder removal devices not classified as anti-st

25、atic can generate electrical charges sufficient to damage ESD devices. 5. Do not use freon-propelled chemicals.These can generate electrical charges sufficient to damage ESD devices. 6. Do not remove a replacement ESD device from its protective package until immediately before you are ready to insta

26、ll it. (Most replacement ESD devices are packaged with leads electrically shorted together by conductive foam, aluminum foil or comparable conductive materials). 7. Immediately before removing the protective material from the leads of a replacement ESD device, touch the protective material to the ch

27、assis or circuit assembly into which the device will by installed. CAUTION : BE SURE NO POWER IS APPLIED TO THE CHASSIS OR CIRCUIT, AND OBSERVE ALL OTHER SAFETY PRECAUTIONS. 8. Minimize bodily motions when handing unpackaged replacement ESD devices. (Otherwise harmless motion such as the brushing to

28、gether of your clothes fabric or the lifting of your foot from a carpeted floor can gen- erate static electricity sufficient to damage an ESD device). CAUTION. GRAPHIC SYMBOLS THE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHIN AN EQUILATERAL TRIANGLE, IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE

29、 PRESENCE OF UNINSULATED “DAN- GEROUS VOLTAGE” THAT MAY BE OF SUFFICIENT MAGNITUDE TO CONSTITUTE A RISK OF ELECTRIC SHOCK. THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIANGLE IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN SERVICE LITERATURE. - 1-6 - -

30、2-1 - SECTION 2. ELECTRICAL VKK CHECK P-SENS CHECK PN903 PIN5, CN302 PIN5 DC -33V check IC301 PIN51 DC -33V check ZD900 voltage check (+5.1V) IC301 PIN26 check ZD901(+) -33V check D901(+) waveform check D901 replacement R902 check ZD900 replacement Q902 TURN ON check C919(-) -33Vup to check D908, D9

31、09 replacement Troubleshooting check Q902 replacement normal TROUBLESHOOTING GUIDE YES YES NO NO NO YES YES YES YES NO NO NO - 2-2 - POWER CHECK Every kinds of Fuse check IC700 “12”(+VH2), 6(-VH2) PIN DC power output check Fuse replacement PN900 PIN1, 5 DC voltage output check D900 PIN2, 3 AC check

32、replacement OK D900 replacement Transformer replacement CN901 PIN5 +12V(D) power check CN901 PIN6, 7 DC +16V over power check D901 AC voltage input checkTransformer replacement IC902(7812) assemble check replacement YES YES YES YES YES YES NO NO NO NO NO NONO CN901 PIN3 +6.2V(D) power check D913 AC

33、voltage input check IC902(7812) assemble check replacement Transformer replacement CN901 PIN6, 7 DC +16V up to power check CN901 PIN5 +12V(D) power check IC901(7805) assemble check replacement YES YES YES NO NO NO NO CN901 PIN4 +12V(A) power check CN901 PIN6, 7 DC +16V over power check D901 AC volta

34、ge input check IC301 PIN76 PWR-CTRL “HIGH” check PATTERN check Transformer replacement IC301 replacement CN901 PIN8 PWR - CTRL “HIGH” check IC903(78R12) assemble check replacement YES YES YES YES NO NO NO NO NO - 2-3 - CN901 PIN11 +8V(A) power check Transformer replacement CD/DVD/KARAOKE FUNCTION CN

35、901 PIN9 PIN DVDCTRL “HIGH” check PATTERN Check IC301 PIN81 DVD-CTRL “HIGH”check IC301 “81”+16 PIN DC +16 over power check IC301replacement YES YES NO NO CN901 PIN5 +12V(D) power check IC904(78R08) check replacement D913 AC voltage input check IC902(7812) assemblecheck replacement Transformer replac

36、ement CN901 PIN12 +5V power check IC901 PIN10 DC +8V over power check IC905(78R05) power check D902/D903 AC power input check YES YES YES YES NONO NO NO NO CN901 PIN14 +3.3V power check OK CN901 PIN10 DC +8V over power check IC907(7805)/IC906(78R33) power check D902/D903 AC power input checkTransfor

37、mer replacement YES YES NO - 2-4 - Muting circuit Troubleshooting (if MUTE) IC301 PIN91 F-MUTE “HIGH” check Q791 “C” PORT “HIGH” check Q700/Q750 “C” PORT SIGNAL check IC301 PIN2 WOOFER-MUTE “HIGH” check Q741 “C” PORT “HIGH” check Q740 “C” PORT signal check Q740 replacement Q700/Q750 replacement Muti

38、ng mode check IC301 replacement Q791 “E” PORT “HIGH” check Q791 replacement normal normal Muting mode check IC301 replacement Q741 “E” PORT HIGH check Q741 replacement PATTERN check PATTERN check YES YES YES YES YES YES YES NO NO NO NO NO NO - 2-5 - Q700/750 “C” signal check JK700 SPEAKER output che

39、ck OK IC602 input check Q795 “E” HIGH check RY700 +12V(A) power check RY700 replacement IC601 input check IC602 replacement IC601 replacement IC605 replacement Q1725 TURN-ON check Speaker short check OK Q1720 “B”(+), (-) DC voltage check IC700 replacement +12V(A) power Troubleshooting refer IC605 in

40、put check each function TROU- BLESHOOTING refer no sound YES YES YES YES YES YES YES YES YES NO NO NO NO NO NO NO NO - 2-6 - AUX FUNCTION SPEAKER output TAPE FUNCTION SPEAKER output IC700 output check(Front -L/R) Output sound Troubleshooting refer IC601 PIN5, 24 input check(AUX -L/R) IC601 replaceme

41、nt IC602 PIN2, 9 input check (FRONT -L/R) IC602 replacement OK OK IC700 input check (Front -L/R) IC602 PIN2, 19 input check (FRONT -L/R) IC700 replacement IC602 replacement JK600 AUX input signal cable or external component sound output check IC601 PIN4, 25 input check (IN -L/R) IC605 PIN4, 11 input

42、 check IC202 PIN5, 20 output check(TAPE -L/R) IC605 replacement IC601 replacement IC601 PIN5, 24 input check(IN-L/R) IC601 replacement Specific FUNCTION MODE has no sound YES YES YES YES YES YES YES YES YES YES NO NO NO NO NO NO NO NO - 2-7 - CD/DVD function speaker output OK IC602 PIN2, 19:F-L/R, 3

43、, 17 PIN :R-L/R, PIN18:CNT input check IC602 replacement IC601 replacement IC601 PIN3, 26 input check (DVD -L/R) PN600 PIN2, 4, 8, 10, 12 output check (DVD F-L/R, R-L/R, CNT) PATTERN check DVD Troubleshooting refer TUNER FUNCTION SPEAKER output OK IC602 PIN2, 19 input check (FRONT -L/R) IC602 replac

44、ement IC601 replacementTUN100 PIN2 VCC +9V check TUN100 PLL -CE/CLK/DI/DO ter- minal DATA correspondence check IC601 PIN4, 25 input check (FRONT -L/R) IC605 PIN3, 5 input check (TUNER -L/R) Pattern check Power +12V(A) check YES YES YES YES YES YES YES YES YES NO NO NO NO NO NO NO NO NO - 2-8 - IC301

45、 U-COM IC Troubleshooting IC301 pin17, 46, 72, 90 +5V power check IC301 PIN26 5V check (POWER-SENS) X301 oscilates or not When IC301 pin11 voltage input LowHigh IC301 replacement CN302 PIN6 DC +5.6V check PATTERN check Troubleshooting Refer P-SENS refer X301 replacement RESET circuit check YES YES Y

46、ES YES YES NO NO NO NO NO IC501(EXPENDER IC) Troubleshooting IC501 PIN16 +5V power check IC501 PIN2, 3 pin CLK Data check CONTROLL function check normal Troubleshooting Refer IC301 TROUBLESHOOTING refer IC301, IC501 pattern check IC301 PIN3, 4 Data check (CD, TAPE FUNCTION change) IC501(BU2090F) rep

47、lacement YES YES YES YES NO NO NO NO - 2-9 - IC700(AMP IC) Troubleshooting PIN10, 14 Signal input check 2(+VH2), 1(-VH2) power check PIN3, 4, 5, 6 signal output check OK Muting circuit refer PIN3, 4, 5, 6 DC check Power IC replacement Power IC replacement YES YES YES YES NO NO TAPE PLAY IC202 “18”pi

48、n VCC check IC202 “5, 20”pin signal output check Muting circuit check Troubleshooting check refer Deck Mecha operation check IC202 replaement Deck Mecha replaement YES YES YES NO NO NO - 2-10 - IC501 Troubleshooting refer TAPE REC check (A252, Q202 On: R273, R223 High IC202 PIN11, 14 signal input ch

49、eck IC202 PIN9, 16 output check IC201 6”(12V) , PIN4 High check L203 PIN5, 6 oscilates or not DECK replaement Q253, Q203 Base “Low” check Q253, Q203 replaement IC202 PIN18 VCC check IC501 Troubleshooting check C236(+) power input check Troubleshooting check refer IC501 Troubleshooting check Q208 replaement L203 replaement Q208 Base 0.6V check Q208 Collector Low Q207 replaement normal YES YES YES YES YES YES YES YES YES NO NO NO NO NO NO NO NO NO Dubbing check (“NORMAL”or “HIGH”) check Q252, 202 “OFF”/”ON”:R273, 223 “LOW”/ “HIGH” Q253, 203 “OFF”/”ON”: