LG-DP270B-dvd-sm 电路图 维修手册.pdf

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1、PORTABLE DVD SERVICE MANUAL MODEL : DP270B CAUTION BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS” IN THIS MANUAL. MODEL : DP270BSERVICE MANUAL P/NO : AFN33673353 APRIL, 2007 Av. Sor Juana lns de la Cruz No 555 Col. San Lorenzo Tlalnepantla, Estado de Mxico CP 54033 Tel. 321 19 00 Fax. 5 65

2、7549 Lada sin costo 01 800 50 481 00 RadioFans.CN 收音机爱 好者资料库 CONTENTS SECTION 1.SUMMARY SECTION 2.EXPLODED VIEWS SECTION 3.ELECTRICAL SECTION 4.REPLACEMENT PARTS LIST RadioFans.CN 收音机爱 好者资料库 1-2 SECTION 1 SUMMARY CONTENTS PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS.1-3 SERVICING PRECAUTIO

3、NS.1-4 GENERAL SERVICING PRECAUTIONS INSULATION CHECKING PRODEDURE ELECTROSTATICALLY SENSITIVE (ES) DEVICES SPECIFICATIONS.1-5 RadioFans.CN 收音机爱 好者资料库 1-3 PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS IMPORTANT SAFETYNOTICE This manual was prepared for use only by properly trained audio-vid

4、eo service technicians. When servicing this product, under no circumstances should the original design be modified or altered without permission from LG Corporation. All components should be replaced only with types identical to those in the original circuit and their physical location, wiring and l

5、ead dress must conform to original layout upon completion of repairs. Special components are also used to prevent x-radiation, shock and fire hazard. These components are indicated by the letter “x” included in their component designators and are required to maintain safe performance. No deviations

6、are allowed without prior approval by LG Corporation. Circuit diagrams may occasionally differ from the actual circuit used. This way, implementation of the latest safety and performance improvement changes into the set is not delayed until the new service literature is printed. CAUTION: Do not atte

7、mpt to modify this product in any way. Never perform customized installations without manufacturers approval. Unauthorized modifications will not only void the warranty, but may lead to property damage or user injury. Service work should be performed only after you are thoroughly familiar with these

8、 safety checks and servicing guidelines. GRAPHIC SYMBOLS The exclamation point within an equilateral triangle is intended to alert the service personnel to important safety information in the service literature. The lightning flash with arrowhead symbol within an equilateral triangle is intended to

9、alert the service personnel to the presence of noninsulated “dangerous voltage” that may be of sufficient magnitude to constitute a risk of electric shock. The pictorial representation of a fuse and its rating within an equilateral triangle is intended to convey to the service personnel the followin

10、g fuse replacement caution notice: CAUTION : FOR CONTINUED PROTECTION AGAINST RISK OF FIRE, REPLACE ALL FUSES WITH THE SAME TYPE AND RATING AS MARKED NEAR EACH FUSE. SERVICE INFORMATION While servicing, use an isolation transformer for protection from AC line shock. After the original service proble

11、m has been corrected, make a check of the following: FIRE AND SHOCK HAZARD 1. Be sure that all components are positioned to avoid a possibility of adjacent component shorts. This is especially important on items trans-ported to and from the repair shop. 2. Verify that all protective devices such as

12、insulators, barriers, covers, shields, strain reliefs, power supply cords, and other hardware have been reinstalled per the original design. Be sure that the safety purpose of the polarized line plug has not been defeated. 3. Soldering must be inspected to discover possible cold solder joints, solde

13、r splashes, or sharp solder points. Be certain to remove all loose foreign particles. 4. Check for physical evidence of damage or deterioration to parts and components, for frayed leads or damaged insulation (including the AC cord), and replace if necessary. 5. No lead or component should touch a hi

14、gh current device or a resistor rated at 1 watt or more. Lead tension around protruding metal surfaces must be avoided. 6. After reassembly of the set, always perform an AC leakage test on all exposed metallic parts of the cabinet (the channel selector knobs, antenna terminals, handle and screws) to

15、 be sure that set is safe to operate without danger of electrical shock. DO NOT USE ALINE ISOLATION TRANSFORMER DURING THIS TEST. Use an AC voltmeter having 5000 ohms per volt or more sensitivity in the following manner: Connect a 1500 ohm, 10 watt resistor, paralleled by a .15 mfd 150V AC type capa

16、citor between a known good earth ground water pipe, conduit, etc.) and the exposed metallic parts, one at a time. Measure the AC voltage across the combination of 1500 ohm resistor and .15 mfd capacitor. Reverse the AC plug by using a non-polarized adaptor and repeat AC voltage measurements for each

17、 exposed metallic part. Voltage measured must not exceed 0.75 volts RMS. This corresponds to 0.5 milliamp AC. Any value exceeding this limit constitutes a potential shock hazard and must be corrected immediately. TIPS ON PROPER INSTALLATION 1. Never install any receiver in a closed-in recess, cubbyh

18、ole, or closely fitting shelf space over, or close to, a 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, near steam radiators where steam leakage is a factor, etc. 3. Avoid placement where draperies may ob

19、struct venting. The customer should also avoid the use of decorative scarves or other coverings that might obstruct ventilation. 4. Wall- and shelf-mounted installations using a commercial mounting kit must follow the factory-approved mounting instructions. A product mounted to a shelf or platform m

20、ust 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. Perform leakage tests on customized installations. 5. Caution customers against mounting a product on a sloping

21、 shelf or in a tilted position, unless the receiver is properly secured. 6. Aproduct on a roll-about cart should be stable in its mounting to the cart. Caution the customer on the hazards of trying to roll a cart with small casters across thresholds or deep pile carpets. 7. Caution customers against

22、 using extension cords. Explain that a forest of extensions, sprouting from a single outlet, can lead to disastrous consequences to home and family. 1-4 SERVICING PRECAUTIONS CAUTION: Before servicing the PORTABLE DVD covered by this service data and its supplements and addends, read and follow the

23、SAFETYPRECAUTIONS. NOTE: if unforeseen circumstances create conflict between the following servicing precautions and any of the safety precautions in this publications, always follow the safety precautions. Remember Safety First : General Servicing Precautions 1.Always unplug the PORTABLE DVD AC pow

24、er cord from the AC power source before: (1) Removing or reinstalling any component, circuit board, module, or any other assembly. (2) Disconnecting or reconnecting any internal electrical plug or other electrical connection. (3) Connecting a test substitute in parallel with an electrolytic capacito

25、r. Caution : A wrong part substitution or incorrect polarity installation of electrolytic capacitors may result in an explosion hazard. 2.Do not spray chemicals on or near this PORTABLE DVD or any of its assemblies. 3.Unless specified otherwise in this service data, clean electrical contacts by appl

26、ying an appropriate contact cleaning 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 which instruments

27、 covered by this service manual might be equipped. 5.Do not apply AC power to this PORTABLE DVD and / or any of its electrical assemblies unless all solid state device heat sinks are correctly installed. 6.Always connect the test instrument ground lead to an appropriate ground before connecting the

28、test instrument positive lead. Always 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 resistance betw

29、een each blade of the attachment plug and accessible conductive parts (Note 1) should be more than 1Mohm. Note 1: Accessible Conductive Parts include Metal panels, Input terminals, Earphone jacks,etc. Electrostatically Sensitive (ES) Devices Some semiconductor (solid state) devices can be damaged ea

30、sily by static electricity. 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 o

31、f 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 touching a known earth ground. Alternatively, obtain and wear a commercially available discharging wrist s

32、trap 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 ES devices, place the assembly on a conductive surface such as aluminum foil, to prevent electrostatic charge buildup or exposure of

33、the assembly. 3.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 as “anti-static” can generate electrical charges sufficient to damage ES devices. 5.Do not use freon-propelled chemical

34、s. These can generate an electrical charge sufficient to damage ES devices. 6.Do not remove a replacement ES device from its protective package until immediately before you are ready to install it. (Most replacement ES devices are packaged with leads electrically shorted together by conductive foam,

35、 aluminum foil,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 ch

36、assis or circuit, 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 electricity suff

37、icient to damage an ES device.) 1-5 SPECIFICATIONS DVD PLAYER Power supplyDC 12V (AC adapter terminal), DC 7.4V (Battery) Power consumption12W with battery Weight190.4g (0.56kg)(without battery pack) External dimensions(W X D X H)(191 X 74 X 39mm) Signal systemNTSL LaserSemiconductor laser, waveleng

38、th 655nm (DVD), 790nm(CD) Frequency range (audio)DVD linear sound:48kHZ sampling 4HZ to 20kHZ 96KHZ sampling4HZ to 44kHZ Signal-to-noise ratio(audio)More than 85dB Dynamic range(audio)More than 85dB Harmonic distortion(audio)0.08% Operatingconditions(audio)Temperature: 41F to 95F, Operation status:

39、Horizontal CONNECTORS Video input/output(VIDEO IN/OUT)2.6x7.8(10/0, 10BC +28/0.10BC) *3F L=1200MM Audio input/output 2.0Vrms (1 KHZ,0 dB), 3.5m X 1 (AUDIO IN/OUT, analog audio) Earphone terminal3.5mm stereo mini jack X 1 LIQUID CRYSTAL DISPLAY Panel size7inches (16:9) Projection systemTN color trans

40、mission Driving systemTFT active matrix SUPPLIED ACCESSORIES RC Aaudio/Video cable1 AC Adapter (AD-DP40)1 Power Cord1 Battery Pack (DP-BT50)1 Remote control1 Battery for Remote control (Lithium)1 2-1 SECTION 2 EXPLODED VIEWS CONTENTS EXPLODED VIEWS.2-2 1. CABINET AND MAIN FRAME SECTION.2-2 3. PACKIN

41、G ACCESSORY SECTION.2-3 2-2 A48 A40 274 293 260 286 275 281 454 455 A00 455 A53 296 295 298 297 451 299 284 285 CABLE1 453 262 267 251 252 253 272 277 A51 261 264 277 A46A A45A FRONT BOARD LCD BOARD KEY BOARD MAIN BOARD 283 809 A42 A46 CABLE3 453 266 278 CABLE2 279 EXPLODED VIEWS 1. CABINET AND MAIN

42、 FRAME SECTION 2-3 2. PACKING ACCESSORY SECTION 808 BATTERY 802A BOX INNER 834 CABLE, CIJAR JACK 806 PLUG ASSY 833 ADAPTER 900 REMOTE CONTROL 801 OWNERS MANUAL 804 PACKING SHEET 803 PACKING 802 BOX CARTON 3-1 SECTION 3 ELECTRICAL CONTENTS LCD PART.3-2 LCD ELECTRICAL TROUBLESHOOTING GUIDE.3-3 BLOCK D

43、IAGRAM.3-5 CIRCUIT DIAGRAM.3-7 PRINTED CIRCUIT DIAGRAM.3-9 MAIN PART.3-11 MAIN ELECTRICAL TROUBLESHOOTING GUIDE.3-11 1. POWER (DC-DC CONVERTER) CIRCUIT.3-11 2. MPEG CIRCUIT .3-14 3. RF/SERVO CIRCUIT.3-15 DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING.3-19 1. SYSTEM 27MHZ CLOCK, RESET & FLASH R/W SIGNAL.3-19 2. SDRAM CLOCK.