LG-DVD2240N-cd-sm 电路图 维修手册.pdf

《LG-DVD2240N-cd-sm 电路图 维修手册.pdf》由会员分享，可在线阅读，更多相关《LG-DVD2240N-cd-sm 电路图 维修手册.pdf（71页珍藏版）》请在收音机爱好者资料库上搜索。

1、SECTION 1 SUMMARY CONTENTS PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS. 1-3 SERVICING PRECAUTIONS. 1-4 General Servicing Precautions Insulation Checking Prodedure Electrostatically Sensitive Devices SPECIFICATIONS. 1-5 LOCATION OF CUSTOMER CONTROLS. 1-6 RadioFans.CN 收音机爱 好者资料库 1-3 CAUTION

2、 : DO NOT ATTEMPT TO MODIFY THIS PRODUCT IN ANY WAY, NEVER PERFORM CUSTOMIZED INSTALLATIONS WITHOUT MANUFAC- TURERS APPROVAL. UNAUTHORIZED MODIFICATIONS WILL NOT ONLY VOID THE WARRANTY, BUT MAY LEAD TO YOUR BEING LIABLE FOR ANY RESULTING PROPERTY DAMAGE OR USER INJURY. SERVICE WORK SHOULD BE PERFORM

3、ED ONLY AFTER YOU ARE THOROUGHLY FAMILIAR WITH ALL OF THE FOLLOWING SAFETY CHECKS AND SERVICING GUIDELINES. TO DO OTHERWISE, INCREASES THE RISK OF POTENTIAL HAZARDS AND INJURY TO THE USER. WHILE SERVICING, USE AN ISOLATION TRANSFORMER FOR PROTEC- TION FROM A.C. LINE SHOCK. SAFETY CHECKS AFTER THE OR

4、IGINAL SERVICE PROBLEM HAS BEEN CORRCTED. A CHECK SHOULD BE MADE OF THE FOLLOWING. SUBJECT : FIRE CONNECT A 1500 OHM 10 WATT RESIS- TOR, PARALLELED BY A .15 MFD. 150.V A.C TYPE CAPACITOR BETWEEN A KNOWN GOOD EARTH GROUND (WATER PIPE, CON- DUIT, ETC.) AND THE EXPOSED METALLIC PARTS, ONE AT A TIME. ME

5、ASURE THE A.C. VOLTAGE ACROSS THE COMBINATION OF 1500 OHM RESISTOR AND .15 MFD CAPACITOR. REVERSE THE A.C. PLUG AND REPEAT A.C. VOLTAGE MEASUREMENTS FOR EACH EXPOSED METALLIC PART. VOLTAGE MEASURED MUST NOT EXCEED 75 VOLTS R.M.S. THIS CORRESPONDS TO 0.5 MILLIAMP A.C ANY VALUE EXCEEDING THIS LIMIT CO

6、NSTITUTES A POTENTIAL SHOCK HAZARD AND MUST BE CORRECTED IMMEDIATELY. SUBJECT: GRAPHIC SYMBOLS THE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHIN AN EQUILATERAL TRIANGLE, IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF UNINSULATED “DANGEROUS VOLTAGE” THAT MAY BE OF SUFFICIENT MAG- NITUD

7、E TO CONSTITUTE A RISK OF ELECTRIC SHOCK. THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIAN- GLE IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN SERVICE LITERATURE. SUBJECT : X-RADIATION 1. BE SURE PROCEDURES AND INSTRUCTIONS TO ALL SERVICE PER- SONNEL C

8、OVER 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 WHEN THE HIGH VOLTAGE IS AT THE FACTORY SPECIFIED LEVEL. THE PROPER VALUE IS GIVEN IN THE APPLICABLE SCHEMATIC. OPERA- TION AT HIGHER VOLTAG

9、ES 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 CONNECTORS MUST BE USED. DEGAUSSING SHIELDS ALSO SERVE AS X-RAY SHIELD IN COLOR SETS, ALWAYS RE-INSTAL

10、L THEM. 3. IT IS ESSNTIAL THAT SERVICE PERSONNEL HAVE AVAILABLE AN ACCURATE AND RELIABLE HIGH VOLTAGE METER. THE CALIBRA TION OF THE METER SHOULD BE CHECKED PERIODICALLY AGAINST A REFERENCE STANDARD, SUCH AS THE ONE AVAILABLE AT YOUR DISTRIBUTOR. 4. WHEN THE HIGH VOLTAGE CIRCUITRY IS OPERATING PROPE

11、RLY THERE IS NO POSSIBILITY OF AN X-RADIATION PROBLEM. EVERY TIME A COLOR CHASSIS IS SERVICED. THE BRIGHTNESS SHOULD BE RUN UP AND DOWN WHILE MONITORING THE HIGH VOLTAGE WITH A METER TO BE CERTAIN THAT THE HIGH VOLTAGE DOES NOT EXCEED THE SPECIFIED VALUE AND THAT IT IS REGULATING CORRECTLY, WE SUGGE

12、ST 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 ON EACH CUSTOMERS INVOICE. 5. WHEN TROUBLESHOOTING AND MAKING TEST MEASUREMENTS IN A PRODUCT WITH A PRO

13、BLEM OF EXCESSIVE HIGH VOLTAGE, AVOID BEING UNNECESSARILY CLOSE TO THE PICTURE TUBE AND THE HIGH VOLTAGE SUPPLY. DO NOT OPERATE THE PRODUCT LONGER THAN IS NECESSARY TO LOCATE THE CAUSE OF EXCES SIVE VOLTAGE. 6. REFER TO HV. B+ AND SHUTDOWN ADJUSTMENT PROCEDURES DESCRIBED IN THE APPROPRIATE SCHEMATIC

14、 AND DIAGRAMS (WHERE USED). SUBJECT: IMPLOSION 1. ALL DIRECT VIEWED PICTURE TUBES ARE EQUIPPED WITH AN INTE GRAL IMPLOSION PROTECTION SYSTEM, BUT CARE SHOULD BE TAKEN TO AVOID DAMAGE DURING INSTALLATION, AVOID SCRATCHING THE TUBE. IF SCRATCHED REPLACE IT. 2. USE ONLY RECOMMENDED FACTORY REPLACEMENT

15、TUBES. SUBJECT : TIPS ON PROPER INSTALLATION 1. NEVER INSTALL ANY PRODUCT IN A CLOSED-IN RECESS, CUBBY- HOLE OR CLOSELY FITTING SHELF SPACE. OVER OR CLOSE TO HEAT DUCT, OR IN THE PATH OF HEATED AIR FLOW. 2. AVOID CONDITIONS OF HIGH HUMIDITY SUCH AS: OUTDOOR PATIO INSTALLATIONS WHERE DEW IS A FACTOR,

16、 NEAR STEAM RADIA- TORS WHERE STEAM LEAKAGE IS A FACTOR, ETC. 3. AVOID PALCEMENT WHERE DRAPERIES MAY OBSTRUCT REAR VENTING. THE CUSTOMER SHOULD ALSO AVOID THE USE OF DEC- ORATIVE SCARVES OR OTHER COVERINGS WHICH MIGHT OBSTRUCT VENTILATION. 4. WALL AND SHELF MOUNTED INSTALLATIONS USING A COMMER- CIAL

17、 MOUNTING KIT. MUST FOLLOW THE FACTORY APPROVED MOUNTING INSTRUCTIONS A PRODUCT MOUNTED TO A SHELF OR PLATFORM MUST RETAIN ITS ORIGINAL FEET (OR THE EQUIVALENT THICKNESS IN SPACERS) TO PROVIDE ADEQUATE AIR FLOW ACROSS THE BOTTOM, BOLTS OR SCREWS USED FOR FASTENERS MUST NOT TOUCH ANY PARTS OR WIRING.

18、 PERFORM LEAKAGE TEST ON CUSTOMIZED INSTALLATIONS. 5. CAUTION CUSTOMERS AGAINST THE MOUNTING OF A PRODUCT ON SLOPING SHELF OR A TILTED POSITION, UNLESS THE PRODUCT IS PROPERLY SECURED. 6. A PRODUCT ON A ROLL-ABOUT CART SHOULD BE STABLE ON ITS MOUNTING TO THE CART. CAUTION THE CUSTOMER ON THE HAZ- AR

19、DS OF TRYING TO ROLL A CART WITH SMALL CASTERS ACROSS THRESHOLDS OR DEEP PILE CARPETS. 7. CAUTION CUSTOMERS AGAINST THE USE OF A CART OR STAND WHICH HAS NOT BEEN LISTED BY UNDERWRITERS LABORATORIES, INC. FOR USE WITH THEIR SPECIFIC MODEL OF TELEVISION RECEIVER OR GENERICALLY APPROVED FOR USE WITH T.

20、V.S OF THE 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 TO HOME AND FAMILY. PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS A.C. VOLTMETER GOOD EART

21、H GROUND SUCH AS THE WATER PIPE. CONDUIT. ETC PLACE THIS PROBE ON EACH EXPOSED METAL PART RadioFans.CN 收音机爱 好者资料库 1-4 SERVICING PRECAUTIONS CAUTION : Before servicing the DVD player covered by this service data and its supplements and addends, read and fol- low the SAFETY PRECAUTIONS. NOTE : if unfo

22、reseen cir- cumstances create conflict between the following servicing precautions and any of the safety precautions in this publi- cations, always follow the safety precautions. Remembers Safety First: General Servicing Precautions 1. Always unplug the DVD player AC power cord from the AC power sou

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

24、titution or incorrect polarity installation of electrolytic capacitors may result in an explosion hazard. 2. Do not spray chemicals on or near this DVD player or any of its assemblies. 3. Unless specified otherwise in this service data, clean electrical contacts by applying an appropriate contact cl

25、eaning solution to the contacts with a pipe cleaner, cotton-tipped swab, or comparable soft applicator. Unless specified otherwise in this service data, lubrication of contacts is not required. 4. Do not defeat any plug/socket B+ voltage interlocks with whitch instruments covered by this service man

26、ual might be equipped. 5. Do not apply AC power to this DVD player and/or any of its electrical assemblies unless all solid-state device heat sinks are cerrectly installed. 6. Always connect test instrument ground lead to the appropriate ground before connection the test instrument positive lead. Al

27、ways remove the test instrument ground lead last. Insulation Checking Procedure Disconnect the attachment plug from the AC outlet and turn the 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

28、 plug and acces- 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) Devices Some semiconductor (solid state) devices can be damaged easily by static electri

29、city. Such components commonly are called Electrostatically Sensitive (ES) Devices. Examples of typical ES devices are integrated circuits and some field effect transistors and semiconductor chip components. The following techniques should be used to help reduce the incidence of component damage cau

30、sed by static electricity. 1. Immediately before handling any semiconductor compo- nent or semiconductor-equipped assembly, drain off any electrostatic charge on your body by touching a known earth ground. Alternatively, obtain and wear a commer- cially available discharging wrist strap device, whic

31、h should be removed for potential 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.

32、 Use only a grounded-tip soldering iron to solder or unsolder ES devices. 4. Use only an anti-static solder removal device. Some solder removal devices not classified a “anti-static” can generate electrical charges sufficient to damage ES devices. 5. Do not use freon-propelled chemicals. These can g

33、enerate electrical charge sufficient to damage ES devices. 6. Do not remove a replacement ES device from its protec tive package until immediately before you are ready to install it. (Most replacement ES devices are packaged with leads electrically shorted together by conductive foam, aluminum foil,

34、 or comparable conductive material). 7. Immediately before removing the protective material from the leads of a replacement ES device, touch the protective material to the chassis or circuit assembly into which the device will be installed. Caution : Be sure no power is applied to the chassis or cir

35、cuit, and observe all other safety precautions. 8. Minimize bodily motions when handling unpackaged replacement ES devices. (Normally harmless motion such as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can generate static elec- tricity sufficient to

36、 damage an ES device.) RadioFans.CN 收音机爱 好者资料库 2-2 DISASSEMBLY CAUTION BEFORE STARTING SERVICING Electronic parts are susceptible to static electricity and may easily damaged, so do not forget to take a proper grounding treatment as required. Many screws are used inside the unit. To prevent missing,

37、 dropping, etc. of the screws, always use a magnetized screw driver in servicing. Several kinds of screws are used and some of them need special cautions. That is, take care of the tapping screws securing molded patrs and fine pitch screws used to secure metal parts. If they are used improperly, the

38、 screw holes will be easily damaged and the parts can not be fixed. (A) Top Case (A) (A) (A) (A) (A) (A) Tray Door Disc Tray Front Panel Stopper Stopper (B) (B) CABINET DISASSEMBLY 1. Top Case 1. Release 7 screws (A). (See Fig. 2-1) 2. Lift the top case with holding the back of it, and remove it in

39、the direction of the arrow Fig. 2-1 Fig. 2-2 Fig. 2-3 3. Front Panel 1. Eject the disc tray. (See Fig. 2-2) 2. Remove the tray door. (See Fig. 2-2) 3. Release 2 screws (B). 4. Pull the front panel toward you while pressing 7 stoppers to disengage, and remove the front panel. (See Fig. 2-3) 2.Tray Do

40、or 1.Eject the disc tray. 2.Lift up the tray door in the direction of the arrow. 2-3 Main Circuit Board Flexible connector Flexible connector A/V Circuit Board (C) (C) (C) (C) (C) (C) (C) (C) (C) (C) (E) (E) (E) (E) (E) (E) Digitron Circuit Board Key Circuit Board Power Code Power Circuit Board (D)

41、(D) (D) (D) Fig. 2-4 Fig. 2-5 Fig. 2-6 CIRCUIT BOARD DISASSEMBLY Note: Before removing the main circuit board, be sure to shortcircuit the laserdiode output land. After replacing the main circuit board, open the land after inserting the flexible connector. (Refer to Mechanism Disassembly) 1. Main/A/

42、V Circuit Board 1. 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 and the connector from main circuit board. 4. Then, remove the main A/V circuit board. 2. Power Circuit Board 1. Relrase 4 screws(D)

43、. (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 digitron circuit board. 2-4 EXPLODED VIEWS 1. Cabinet and Main Frame Section 463 260 452 462 250 462 462 462 462 463 463 A47 A43 A00 463 A46 PBS00 PBK00 PBT00 452 283 46

44、3 280 277 278 463 452 463 A48 463 463 300 PBJ00 455 A 5 4 3 2 1 BCD 2-5 2.Packing Accessory Section 3.Remote Control Section BATTERY808 CABLE806 PACKING SHEET804 PACKING803 811 812 813 OWNERS MANUAL801 REMOCON900 BOX CARTONX802 PACKING803 902 903 904 905 901 906 908 907 909 900 3-2 Replace Q908 and

45、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 abnormal when the IC103 oscillates intermittently. The

46、resistor value of both terminal is measured with DVM crossing each other to check the each element is normal or abnormal. (It is normal when the numerical value is different each other.) ELECTRICAL TROUBLESHOOTING GUIDE Is F901 normal? Is IC901 Pin 3 switching normally? A primary side is abnormal. C

47、heck the GND of C901 and IC901 Pin 3 with oscilloscope. When IC901 oscillating Secondary side is abnormal. In condition of DC140V. (Feedback is abnormal) After connect CON903 Pin 1 , 3 short. YES YESYES YES YES YES YES YES YES YES YES YES YES YES YES NO NONO NO NO NO (Fig. 3-1) IC901 Pin 3 Normal sw

48、itching waveform on the stand-by mode at the AC110V NO NO NO NO NO NO NO NO Is CN903 Pin 3 5.2V? Is voltage of BD901 140V? Are R907, D902, D903 and R902 normal? Are D901, R904, R905 and R906 normal? Is PC901 normal? Are CON902 Pin 5 , 6 and 9 5V? Is CON904 Pin 3 8V? Is CON902 Pin 3 12V? Are CON903 Pin 5 -24V, Pin 7 -20V and Pin 8 -16V? END END (A) To (A). START Does oscillate continuously when the CON903 is disconnected ? Front Circuit Board is abnormal Are D908, D909, D907, D910, D906 and D905 normal? Replace defective parts. Check Q904 and ZD903. Replace IC902. Repl