LG-DVD2240N-cd-sm 维修电路原理图.pdf

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1、SECTION 1SUMMARYCONTENTSPRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS. 1-3SERVICING PRECAUTIONS. 1-4General Servicing PrecautionsInsulation Checking ProdedureElectrostatically Sensitive DevicesSPECIFICATIONS. 1-5LOCATION OF CUSTOMER CONTROLS. 1-6RadioFans.CN 收音机爱 好者资料库1-3CAUTION : DO NOT AT

2、TEMPT TO MODIFY THIS PRODUCT IN ANY WAY,NEVER PERFORM CUSTOMIZED INSTALLATIONS WITHOUT MANUFAC-TURERS APPROVAL. UNAUTHORIZED MODIFICATIONS WILL NOT ONLYVOID THE WARRANTY, BUT MAY LEAD TO YOUR BEING LIABLE FOR ANYRESULTING PROPERTY DAMAGE OR USER INJURY.SERVICE WORK SHOULD BE PERFORMED ONLY AFTER YOU

3、 ARETHOROUGHLY FAMILIAR WITH ALL OF THE FOLLOWING SAFETYCHECKS AND SERVICING GUIDELINES. TO DO OTHERWISE,INCREASES THE RISK OF POTENTIAL HAZARDS AND INJURY TO THEUSER.WHILE SERVICING, USE AN ISOLATION TRANSFORMER FOR PROTEC-TION FROM A.C. LINE SHOCK.SAFETY CHECKSAFTER THE ORIGINAL SERVICE PROBLEM HA

4、S BEEN CORRCTED. ACHECK SHOULD BE MADE OF THE FOLLOWING.SUBJECT : FIRE & SHOCK HAZARD1. BE SURE THAT ALL COMPONENTS ARE POSITIONED IN SUCH A WAYAS TO AVOID POSSIBILITY OF ADJACENT COMPONENT SHORTS.THIS IS ESPECIALLY IMPORTANT ON THOSE MODULES WHICH ARETRANSPORTED TO AND FROM THE REPAIR SHOP.2. NEVER

5、 RELEASE A REPAIR UNLESS ALL PROTECTIVE DEVICESSUCH AS INSULATORS, BARRIERS, COVERS, SHIELDS, STRAIN RELIEFS, POWER SUPPLY CORDS, AND OTHER HARDWARE HAVEBEEN REINSTALLED PER ORIGINAL DESIGN. BE SURE THAT THESAFETY PURPOSE OF THE POLARIZED LINE PLUG HAS NOT BEENDEFEATED.3. SOLDERING MUST BE INSPECTED

6、 TO DISCOVER POSSIBLE COLDSOLDER JOINTS, SOLDER SPLASHES OR SHARP SOLDER POINTS.BE CERTAIN TO REMOVE ALL LOOSE FOREIGN PARTICLES.4. CHECK FOR PHYSICAL EVIDENCE OF DAMAGE OR DETERIORATIONTO PARTS AND COMPONENTS. FOR FRAYED LEADS, DAMAGEDINSULATION (INCLUDING A.C. CORD). AND REPLACE IF NECESSARYFOLLOW

7、 ORIGINAL LAYOUT, LEAD LENGTH AND DRESS.5. NO LEAD OR COMPONENT SHOULD TOUCH A RECIVING TUBE ORA RESISTOR RATED AT 1 WATT OR MORE. LEAD TENSION AROUNDPROTRUNING METAL SURFACES MUST BE AVOIDED.6. ALL CRITICAL COMPONENTS SUCH AS FUSES, FLAMEPROOFRESISTORS, CAPACITORS, ETC. MUST BE REPLACED WITH EXACTF

8、ACTORY TYPES, DO NOT USE REPLACEMENT COMPONENTSOTHER THAN THOSE SPECIFIED OR MAKE UNRECOMMENDED CIR-CUIT MODIFICATIONS.7. AFTER RE-ASSEMBLY OF THE SET ALWAYS PERFORM AN A.C.LEAKAGE TEST ON ALL EXPOSED METALLIC PARTS OF THE CABI-NET, (THE CHANNEL SELECTOR KNOB, ANTENNA TERMINALS. HAN-DLE AND SCREWS)

9、TO BE SURE THE SET IS SAFE TO OPERATEWITHOUT DANGER OF ELECTRICAL SHOCK. DO NOT USE A LINE ISOLATION TRANSFORMER DURING THIS TEST USE AN A.C. VOLT-METER, HAVING 5000 OHMS PER VOLT OR MORE SENSITIVITY, INTHE FOLLOWING MANNER; CONNECT A 1500 OHM 10 WATT RESIS-TOR, PARALLELED BY A .15 MFD. 150.V A.C TY

10、PE CAPACITORBETWEEN A KNOWN GOOD EARTH GROUND (WATER PIPE, CON-DUIT, ETC.) AND THE EXPOSED METALLIC PARTS, ONE AT A TIME.MEASURE THE A.C. VOLTAGE ACROSS THE COMBINATION OF 1500 OHM RESISTOR AND .15 MFD CAPACITOR. REVERSE THE A.C. PLUGAND REPEAT A.C. VOLTAGE MEASUREMENTS FOR EACH EXPOSED METALLIC PAR

11、T. VOLTAGE MEASURED MUST NOT EXCEED 75VOLTS R.M.S. THIS CORRESPONDS TO 0.5 MILLIAMP A.C ANYVALUE EXCEEDING THIS LIMIT CONSTITUTES A POTENTIAL SHOCKHAZARD AND MUST BE CORRECTED IMMEDIATELY.SUBJECT: GRAPHIC SYMBOLSTHE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHINAN EQUILATERAL TRIANGLE, IS INTENDED TO

12、 ALERT THESERVICE PERSONNEL TO THE PRESENCE OF UNINSULATED“DANGEROUS VOLTAGE” THAT MAY BE OF SUFFICIENT MAG-NITUDE TO CONSTITUTE A RISK OF ELECTRIC SHOCK.THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIAN-GLE IS INTENDED TO ALERT THE SERVICE PERSONNEL TOTHE PRESENCE OF IMPORTANT SAFETY INFORMATION IN

13、SERVICE LITERATURE.SUBJECT : X-RADIATION1. BE SURE PROCEDURES AND INSTRUCTIONS TO ALL SERVICE PER-SONNEL COVER THE SUBJECT OF X-RADIATION. THE ONLY POTEN-TIAL SOURCE OF X-RAYS IN CURRENT T.V. RECEIVERS IS THE PIC-TURE TUBE. HOWEVER, THIS TUBE DOES NOT EMIT X-RAYS WHENTHE HIGH VOLTAGE IS AT THE FACTO

14、RY SPECIFIED LEVEL. THE PROPER VALUE IS GIVEN IN THE APPLICABLE SCHEMATIC. OPERA-TION AT HIGHER VOLTAGES MAY CAUSE A FAILURE OF THE PIC-TURE TUBE OR HIGH VOLTAGE SUPPLY AND, UNDER CERTAIN CIR-CUMSTANCES, MAY PRODUCE RADIATION IN EXCESS OF DESIR-ABLE LEVELS.2. ONLY FACTORY SPECIFIED C.R.T. ANODE CONN

15、ECTORS MUST BEUSED. DEGAUSSING SHIELDS ALSO SERVE AS X-RAY SHIELD INCOLOR SETS, ALWAYS RE-INSTALL THEM.3. IT IS ESSNTIAL THAT SERVICE PERSONNEL HAVE AVAILABLE ANACCURATE AND RELIABLE HIGH VOLTAGE METER. THE CALIBRATION OF THE METER SHOULD BE CHECKED PERIODICALLYAGAINST A REFERENCE STANDARD, SUCH AS

16、THE ONE AVAILABLEAT YOUR DISTRIBUTOR.4. WHEN THE HIGH VOLTAGE CIRCUITRY IS OPERATING PROPERLYTHERE IS NO POSSIBILITY OF AN X-RADIATION PROBLEM. EVERYTIME A COLOR CHASSIS IS SERVICED. THE BRIGHTNESS SHOULDBE RUN UP AND DOWN WHILE MONITORING THE HIGH VOLTAGEWITH A METER TO BE CERTAIN THAT THE HIGH VOL

17、TAGE DOESNOT EXCEED THE SPECIFIED VALUE AND THAT IT IS REGULATINGCORRECTLY, WE SUGGEST THAT YOU AND YOUR SERVICE ORGA-NIZATION REVIEW TEST PROCEDURES SO THAT VOLTAGE REGU-LATION IS ALWAYS CHECKED AS A STANDARD SERVICING PROCE-DURE. AND THAT THE HIGH VOLTAGE READING BE RECORDER ONEACH CUSTOMERS INVOI

18、CE.5. WHEN TROUBLESHOOTING AND MAKING TEST MEASUREMENTS INA PRODUCT WITH A PROBLEM OF EXCESSIVE HIGH VOLTAGE,AVOID BEING UNNECESSARILY CLOSE TO THE PICTURE TUBE ANDTHE HIGH VOLTAGE SUPPLY. DO NOT OPERATE THE PRODUCTLONGER THAN IS NECESSARY TO LOCATE THE CAUSE OF EXCESSIVE VOLTAGE.6. REFER TO HV. B+

19、AND SHUTDOWN ADJUSTMENT PROCEDURES DESCRIBED IN THE APPROPRIATE SCHEMATIC AND DIAGRAMS(WHERE USED).SUBJECT: IMPLOSION1. ALL DIRECT VIEWED PICTURE TUBES ARE EQUIPPED WITH AN INTEGRAL IMPLOSION PROTECTION SYSTEM, BUT CARE SHOULD BETAKEN TO AVOID DAMAGE DURING INSTALLATION, AVOIDSCRATCHING THE TUBE. IF

20、 SCRATCHED REPLACE IT.2. USE ONLY RECOMMENDED FACTORY REPLACEMENT TUBES.SUBJECT : TIPS ON PROPER INSTALLATION1. NEVER INSTALL ANY PRODUCT IN A CLOSED-IN RECESS, CUBBY-HOLE OR CLOSELY FITTING SHELF SPACE. OVER OR CLOSE TOHEAT DUCT, OR IN THE PATH OF HEATED AIR FLOW.2. AVOID CONDITIONS OF HIGH HUMIDIT

21、Y SUCH AS: OUTDOOR PATIOINSTALLATIONS WHERE DEW IS A FACTOR, NEAR STEAM RADIA-TORS WHERE STEAM LEAKAGE IS A FACTOR, ETC.3. AVOID PALCEMENT WHERE DRAPERIES MAY OBSTRUCT REARVENTING. THE CUSTOMER SHOULD ALSO AVOID THE USE OF DEC-ORATIVE SCARVES OR OTHER COVERINGS WHICH MIGHTOBSTRUCT VENTILATION.4. WAL

22、L AND SHELF MOUNTED INSTALLATIONS USING A COMMER-CIAL MOUNTING KIT. MUST FOLLOW THE FACTORY APPROVED MOUNTING INSTRUCTIONS A PRODUCT MOUNTED TO A SHELF ORPLATFORM MUST RETAIN ITS ORIGINAL FEET (OR THE EQUIVALENTTHICKNESS IN SPACERS) TO PROVIDE ADEQUATE AIR FLOW ACROSS THE BOTTOM, BOLTS OR SCREWS USE

23、D FOR FASTENERSMUST NOT TOUCH ANY PARTS OR WIRING. PERFORM LEAKAGETEST ON CUSTOMIZED INSTALLATIONS.5. CAUTION CUSTOMERS AGAINST THE MOUNTING OF A PRODUCT ONSLOPING SHELF OR A TILTED POSITION, UNLESS THE PRODUCT ISPROPERLY SECURED.6. A PRODUCT ON A ROLL-ABOUT CART SHOULD BE STABLE ON ITSMOUNTING TO T

24、HE CART. CAUTION THE CUSTOMER ON THE HAZ-ARDS OF TRYING TO ROLL A CART WITH SMALL CASTERS ACROSSTHRESHOLDS OR DEEP PILE CARPETS.7. CAUTION CUSTOMERS AGAINST THE USE OF A CART OR STANDWHICH HAS NOT BEEN LISTED BY UNDERWRITERS LABORATORIES, INC. FOR USE WITH THEIR SPECIFIC MODEL OF TELEVISION RECEIVER

25、 OR GENERICALLY APPROVED FOR USE WITH T.V.S OFTHE SAME OR LARGER SCREEN SIZE.8. CAUTION CUSTOMERS AGAINST THE USE OF EXTENSION CORDS, EXPLAIN THAT A FOREST OF EXTENSIONS SPROUTING FROM A SIN-GLE OUTLET CAN LEAD TO DISASTROUS CONSEQUENCES TOHOME AND FAMILY.PRODUCT SAFETY SERVICING GUIDELINES FOR VIDE

26、O PRODUCTSA.C. VOLTMETERGOOD EARTH GROUNDSUCH AS THE WATERPIPE. CONDUIT. ETCPLACE THIS PROBEON EACH EXPOSEDMETAL PARTRadioFans.CN 收音机爱 好者资料库1-4SERVICING PRECAUTIONSCAUTION : Before servicing the DVD player covered by thisservice data and its supplements and addends, read and fol-low the SAFETY PRECA

27、UTIONS. NOTE : if unforeseen cir-cumstances create conflict between the following servicingprecautions and any of the safety precautions in this publi-cations, always follow the safety precautions.Remembers Safety First:General Servicing Precautions1. Always unplug the DVD player AC power cord from

28、the ACpower source before:(1)Removing or reinstalling any component, circuit board, module, or any other assembly.(2)Disconnection or reconnecting any internal electricalplug or other electrical connection.(3)Connecting a test substitute in parallel with an elec-trolytic capacitor.Caution : A wrong

29、part substitution or incorrect polarity installation of electrolytic capacitors may resultin an explosion hazard.2. Do not spray chemicals on or near this DVD player or anyof its assemblies.3. Unless specified otherwise in this service data, cleanelectrical contacts by applying an appropriate contac

30、t cleaning solution to the contacts with a pipe cleaner,cotton-tipped swab, or comparable soft applicator.Unless specified otherwise in this service data, lubricationof contacts is not required.4. Do not defeat any plug/socket B+ voltage interlocks withwhitch instruments covered by this service manu

31、al mightbe equipped.5. Do not apply AC power to this DVD player and/or any ofitselectrical assemblies unless all solid-state device heatsinks are cerrectly installed.6. Always connect test instrument ground lead to theappropriate ground before connection the test instrumentpositive lead. Always remo

32、ve the test instrument ground lead last.Insulation Checking ProcedureDisconnect the attachment plug from the AC outlet and turnthe power on. Connect an insulation resistance meter(500V)to the blades of the attachment plug. The insulation resis-tance between each blade of the attachment plug and acce

33、s-sible conductive parts (Note 1) should be more than 1M-ohm.Note 1 : Accessible Conductive Parts including Metal pan-els, Input terminals, Earphone jacks, etc.Electrostatically Sensitive (ES) DevicesSome semiconductor (solid state) devices can be damagedeasily by static electricity. Such components

34、 commonly arecalled Electrostatically Sensitive (ES) Devices. Examples oftypical ES devices are integrated circuits and some fieldeffect transistors and semiconductor chip components.The following techniques should be used to help reduce theincidence of component damage caused by static electricity.

35、1. Immediately before handling any semiconductor compo-nent or semiconductor-equipped assembly, drain off anyelectrostatic charge on your body by touching a knownearth ground. Alternatively, obtain and wear a commer-cially available discharging wrist strap device, which should be removed for potenti

36、al shock reasons prior to applying power to the unit under test.2. After removing an electrical assembly equipped with ES devices, place the assembly on a conductive surface such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.3. Use only a grounded-tip solderin

37、g iron to solder orunsolder ES devices.4. Use only an anti-static solder removal device. Somesolder removal devices not classified a “anti-static” cangenerate electrical charges sufficient to damage ES devices.5. Do not use freon-propelled chemicals. These cangenerate electrical charge sufficient to

38、 damage ESdevices.6. Do not remove a replacement ES device from its protective package until immediately before you are ready toinstall it. (Most replacement ES devices are packaged withleads electrically shorted together by conductive foam,aluminum foil, or comparable conductive material).7. Immedi

39、ately before removing the protective material fromthe leads of a replacement ES device, touch the protectivematerial to the chassis or circuit assembly into which thedevice will be installed.Caution : Be sure no power is applied to the chassis orcircuit, and observe all other safety precautions.8. M

40、inimize bodily motions when handling unpackaged replacement ES devices. (Normally harmless motion such as the brushing together of your clothes fabric or the liftingof your foot from a carpeted floor can generate static elec-tricity sufficient to damage an ES device.)2-2DISASSEMBLYCAUTION BEFORE STA

41、RTING SERVICINGElectronic parts are susceptible to static electricity and may easily damaged, so do not forget to take aproper grounding treatment as required.Many screws are used inside the unit. To prevent missing, dropping, etc. of the screws, always use amagnetized screw driver in servicing. Sev

42、eral kinds of screws are used and some of them need specialcautions. That is, take care of the tapping screws securing molded patrs and fine pitch screws used to securemetal parts. If they are used improperly, the screw holes will be easily damaged and the parts can not be fixed.(A)Top Case(A)(A)(A)

43、(A)(A)(A)Tray DoorDisc TrayFront PanelStopperStopper(B)(B)CABINET DISASSEMBLY1. Top Case1. Release 7 screws (A). (See Fig. 2-1)2. Lift the top case with holding the back of it,and remove it in the direction of the arrowFig. 2-1Fig. 2-2Fig. 2-33. Front Panel1. Eject the disc tray. (See Fig. 2-2)2. Re

44、move the tray door. (See Fig. 2-2)3. Release 2 screws (B).4. Pull the front panel toward you while pressing7 stoppers to disengage, and remove the frontpanel. (See Fig. 2-3)2.Tray Door1.Eject the disc tray. 2.Lift up the tray door in the direction of thearrow.2-3Main Circuit BoardFlexibleconnectorFl

45、exibleconnectorA/V Circuit Board(C)(C)(C)(C)(C)(C)(C)(C)(C)(C)(E)(E)(E)(E)(E)(E)DigitronCircuit BoardKeyCircuit BoardPower CodePowerCircuitBoard(D)(D)(D)(D)Fig. 2-4Fig. 2-5Fig. 2-6CIRCUIT BOARD DISASSEMBLYNote:Before removing the main circuit board, be sure toshortcircuit the laserdiode output land.

46、After replacing the main circuit board, open the landafter inserting the flexible connector.(Refer to Mechanism Disassembly)1. Main/A/V Circuit Board1. Remove the top case.(See Fig.2-1)2. Release 10 screws (C), and take out the main /AV circuit board.(See Fig.2-4)3. Remove the flexible connectors an

47、d theconnector from main circuit board.4. Then, remove the main A/V circuit board.2. Power Circuit Board1. Relrase 4 screws(D). (See Fig. 2-5)3. Digitron and Key Circuit Board 1. Remove the front panel.(See Fig. 2-3)2. Release 8 screws(E), and remove the digitroncircuit board.2-4EXPLODED VIEWS1. Cab

48、inet and Main Frame Section463260452462250462462462462463463A47A43A00463A46PBS00PBK00PBT00452283463280277278463452463A48463463300PBJ00455A54321BCD2-52.Packing Accessory Section3.Remote Control SectionBATTERY808CABLE806PACKING SHEET804PACKING803811812813OWNERS MANUAL801REMOCON900BOX CARTONX802PACKING

49、8039029039049059019069089079099003-2Replace Q908and Q909.1. Power Circuit Input Voltage : 90V - 135V It is possible to malfunction, if the unload condition is left for a long time when power is on. (More than Dummy load 100mA) A Primary side is abnormal when the fuse is short, secondary side is abno

50、rmal when the IC103 oscillatesintermittently. The resistor value of both terminal is measured with DVM crossing each other to check the each element isnormal or abnormal. (It is normal when the numerical value is different each other.)ELECTRICAL TROUBLESHOOTING GUIDEIs F901 normal?Is IC901 Pin 3swit