LG-LGXBR342-cdrec-sm 电路图 维修手册.pdf

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1、VCR+DVD RECODER SERVICE MANUAL MODEL : LGXBR342 CAUTION BEFORE SERVICING THE UNIT, READ THE “SAFETYPRECAUTIONS” IN THIS MANUAL. MODEL : LGXBR342SERVICE MANUAL P/NO : 3829RGN002W Printed in Korea JANUARY, 2004 CD-R/RW RadioFans.CN 收音机爱 好者资料库 1-1 SECTION 1 SUMMARY CONTENTS PRODUCT SAFETY SERVICING GUI

2、DELINES FOR VIDEO PRODUCTS. 1-2 SERVICING PRECAUTIONS. 1-3 SPECIFICATIONS. 1-4 RadioFans.CN 收音机爱 好者资料库 1-2 IMPORTANT SAFETY NOTICE This manual was prepared for use only by properly trained audio-video service technicians. When servicing this product, under no circumstances should the original design

3、 be modified or altered without permission from Zenith Electronics Corporation. All components should be replaced only with types identical to those in the original circuit and their physical location, wiring and lead dress must conform to original layout upon completion of repairs. Special componen

4、ts are also used to prevent x-radiation, shock and fire haz- ard. These components are indicated by the letter “x” included in their compo- nent designators and are required to maintain safe performance. No deviations are allowed without prior approval by Zenith Electronics Corporation. Circuit diag

5、rams 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 attempt to modify this product in any way. Never perform customized in

6、stallations without manufacturers approval. Unauthorized modi- fications 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 safety checks and servicing guidelines. GRAPHIC SYMBOLS The exc

7、lamation 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 tri- angle is intended to alert the service personnel to the presence of noninsulated “d

8、angerous voltage” that may be of sufficient magni- tude to constitute a risk of electric shock. The pictorial representation of a fuse and its rating within an equi- lateral triangle is intended to convey to the service personnel the following fuse replacement caution notice: CAUTION: FOR CONTINUED

9、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 problem has been corrected, make a check of the fol- lowing: FIRE

10、 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 insulators, barriers, covers, shields, strain reliefs, po

11、wer 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, solder splashes, or sharp solder points. Be certain to remove

12、all loose foreign par- ticles. 4. Check for physical evidence of damage or deterioration to parts and compo- nents, for frayed leads or damaged insulation (including the AC cord), and replace if necessary. 5. No lead or component should touch a high current device or a resistor rated at 1 watt or mo

13、re. 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 be sure that set is safe to operate without danger o

14、f electrical shock. DO NOT USE A LINE ISOLATION TRANS- FORMER 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 capacitor between a known good earth ground water pipe

15、, conduit, etc.) and the exposed metal- lic 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 exposed metallic part. Voltage measured must no

16、t exceed 0.75 volts RMS. This corresponds to 0.5 milliamp AC. Any value exceeding this limit consti- tutes a potential shock hazard and must be corrected immediately. TIPS ON PROPER INSTALLATION 1. Never install any receiver in a closed-in recess, cubbyhole, or closely fitting shelf space over, or c

17、lose 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 obstruct venting. The customer should also avoid

18、 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 must retain its original feet (or the equivalen

19、t 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 shelf or in a tilt- ed position, unless the r

20、eceiver is properly secured. 6. A product 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 cast- ers across thresholds or deep pile carpets. 7. Caution customers against using extension cords. Explain that a fo

21、rest of extensions, sprouting from a single outlet, can lead to disastrous conse- quences to home and family. A.C. Voltmeter 1500 OHM 10 WATT Place this probe on each exposed metal part. Good Earth Ground such as the Water Pipe, Conduit, etc. 0.15uF PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PROD

22、UCTS RadioFans.CN 收音机爱 好者资料库 1-3 SERVICING PRECAUTIONS CAUTION: Before servicing the VCR + DVD RECODER cov- ered by this service data and its supplements and addends, read and follow the SAFETY PRECAUTIONS. NOTE: if unforeseen circumstances create conflict between the fol- lowing servicing precautio

23、ns and any of the safety precau- tions in this publications, always follow the safety precau- tions. Remember Safety First: General Servicing Precautions 1. Always unplug the VCR + DVD RECODER AC power cord from the AC power source before: (1)Removing or reinstalling any component, circuit board, mo

24、dule, 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 elec- trolytic capacitor. Caution: A wrong part substitution or incorrect polarity installation of electrolytic capacitors ma

25、y result in an explosion hazard. 2. Do not spray chemicals on or near this VCR + DVD RECODER or any of its assemblies. 3. Unless specified otherwise in this service data, clean electrical contacts by applying an appropriate contact cleaning solution to the contacts with a pipe cleaner, cotton-tipped

26、 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 manual might be equipped. 5. Do not apply AC power to this VCR + DVD

27、RECODER 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 test instrument positive lead. Always remove the test instrument ground lead last. Ins

28、ulation 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 plug and acces- sible conductive parts (Note 1) sho

29、uld be more than 1M- ohm. 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 easily by static electricity. Such components commonly are called Electrostaticall

30、y 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 caused by static electricity. 1. Immediately before handling

31、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, which should be removed for potential shock reasons prior to a

32、pplying 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 soldering iron to solder or unsol

33、der 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 chemicals. These can generate an electrical charge sufficient to damage ES devi

34、ces. 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,or comparable conductive material). 7. Immediately be

35、fore 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 circuit, and observe all other safety precautions. 8. Mini

36、mize 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 damage an ES device.) 1-4 SPECIFICATIONS General Power

37、 requirementsAC 120V, 50/60 Hz Power consumption35W Dimensions (approx.)430 X 83.5 X 360 mm Mass (approx.)6.8 kg Operating temperature 5 C 40 C Standard Condition -20 C -60 C Signal system NTSC VDR PART Read Disc FormatDVD Disc : DVD Video Specification Book. CD-DA Disc : RED Book. Write Disc Format

38、 DVD-R/DVD-R/W Disc : DVD-RW Recorder Specification Book Video SystemNTSC Data MultiplexingMPEG-2(ISO/IEC 13818-1) Data Decoding StandardsMPEG-1, MPEG-2 Audio CompressionRead : AC-3 : ATSC Standard for ATV MPEG-1, MPEG-2 Write : MPEG-1, Layer-2 VCR PART Video Head SystemDouble azimuth 4head helical

39、scanning Tape FormatTape width 12.7mm(0.5 inch) Timer24hours display type OUTOUT VIDEO OUTPUTS 1.0 V (p-p), 75 negative sync,RCA jack x 1 S-VIDEO OUTPUT(Y)1.0 V (p-p), 75 negative sync, Mini DIN 4-pin x 1 (C)0.3 V (p-p), 75 COMPONENT VIDEO OUTPUT(Y)1.0 V (p-p),75 negative sync, RCA jack x 1 (Pb)/(Pr

40、)0.7 V (p-p), 75 Audio output (analog output)(-)6dBm, less than 1k RCA jack x 2 Audio output (digital output)0.5 V (p-p), 75 , RCA jack x 1 Audio output (optical output)5 V (p-p), 75 , Optical connector x 1 2-1 SECTION 2 CABINET & MAIN CHASSIS CONTENTS EXPLODED VIEWS.2-2 1. Cabinet and Main Frame Se

41、ction.2-2 2. Packing Accessory Section.2-3 2-2 EXPLODED VIEWS 1. Cabinet and Main Frame Section 284 261 452 452 320 265 467 468 263 264 250 300 463 463 463 261A 261A 261A 283 280? A43 457 276 260 457 463 457 469 469 A50 A47 A48 A46 A00 457 TU701 323 A52 270 A26 A60 466 463 466 256 463 255 469 257 A4

42、7A A44 452 A 5 4 3 2 1 BCD 2-3 2. Packing Accessory Section BATTERY808 BAG804 PACKING803 806 INSTRUCTION ASSEMBLY CABLE(COAXIAL) 810 CABLE ASSY RF 801 REMOCON900 BOX CARTON802 PACKING803 811 812 PLUG ASSY 1WAY PLUG ASSY 2WAY OPTIONAL PARTS 3-13-1 SECTION 3 ELECTRICAL CONTENTS OVERALL WIRING DIAGRAM.

43、3-2 VCR PART ELECTRICAL ADJUSTMENT PROCEDURES.3-3 VCR ELECTRICAL TROUBLESHOOTING GUIDE.3-4 1. POWER(SMPS) CIRCUIT.3-4 2. SYSTEM/KEY CIRCUIT .3-7 3. SERVO CIRCUIT .3-8 4. OSD CIRCUIT .3-10 5. Y/C CIRCUIT.3-11 6. TUNER/IF CIRCUIT.3-15 7. Hi-Fi CIRCUIT.3-17 BLOCK DIAGRAMS.3-20 1. POWER(SMPS) BLOCK DIAG

44、RAM.3-20 2. TUNER/MTZ BLOCK DIAGRAM.3-22 3. Y/C BLOCK DIAGRAM.3-24 4. NORMAL AUDIO BLOCK DIAGRAM.3-26 5. JACK BLOCK DIAGRAM .3-28 6. Hi-Fi BLOCK DIAGRAM.3-30 7. SYSTEM BLOCK DIAGRAM.3-32 CIRCUIT DIAGRAMS.3-34 1. POWER(SMPS) CIRCUIT DIAGRAM.3-34 2. TU/IF CIRCUIT DIAGRAM .3-36 3. A/V CIRCUIT DIAGRAM.3-38 4. JACK CIRCUIT DIAGRAM.3-40 5. Hi-Fi CIRCUIT DIAGRAM.3-42 6. SYSTEM CIRCUIT DIAGRAM.3-44 7. TIMER CIRCUIT DIAGRAM .3-46 WAVEFORMS .3-48 CIRCUIT VOL