LG-LHCX245-crs-sm 电路图 维修手册.pdf

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1、DVD/VCR COMBI RECEIVER Combi Receiver System SERVICE MANUAL MODELS : LH-CX245(LH-CX245X)/LH-CX246(LH-CX246X) LH-CX247(LH-CX247X)/LH-CX640(LH-CX640X) CAUTION BEFORE SERVICING THE UNIT, READ THE “SAFETYPRECAUTIONS” IN THIS MANUAL. LH-CX640(LH-CX640X)LH-CX245(LH-CX245X) LH-CX247(LH-CX247X) LH-CX246(LH-

2、CX246X) MODELS : LH-CX245(LH-CX245X)/LH-CX246(LH-CX246X)/LH-CX247(LH-CX247X)/LH-CX640(LH-CX640X)SERVICE MANUAL P/NO : 3829RGP015NDECEMBER, 2004 PROG./ PRESET PROG. RadioFans.CN 收音机爱 好者资料库 CONTENTS SECTION 1 . . . . SUMMARY SECTION 2 . . . . CABINET 23.39 mm/s (SP), 16.69 mm/s (LP) NTSC (Playback onl

3、y); 35.35 mm/s (SP), 16.67 mm/s (LP), 11.12 mm/s (EP) Maximum recording timeSP: 4 h (E-240 tape), LP: 8 h (E-240 tape) Rewind timeAbout 180 min (E-180 tape) Input levelVIDEO:1.0 V(p-p), 75 ohms, unbalanced AUDIO: -6.0 dBm, more than 10 kohms (SCART) -6.0 dBm, more than 47 kohms (RCA) Output levelVID

4、EO:1.0 V(p-p), 75 ohms, unbalanced Signal-to-noise ratioVIDEO: More than 43 dB AUDIO: More than 72 dB (Hi-Fi) More than 42 dB (Mono) Dynamic rangeAUDIO: More than 85 dB Tuner Section Tuning rangeFM: 87.5 - 108.0 MHz AM: 522 - 1611 kHz Intermediate frequencyFM: 10.7 MHz AM: 450 kHz Amplifier(LH-CX245

5、/LH-CX247) Stereo mode 25W + 25W (6 ohm at 1 kHz, THD 10%) Surround mode Front: 25W + 25W (THD 10%) Centre: 25W Surround: 25W + 25W (6 ohm at 1 kHz, THD 10%) Subwoofer: 60W (8 ohm at 30 Hz, THD 10%) Speaker Section(LH-CX245/LH-CX247) Satellite Speaker (LHS-CX245T/LHS-CX247T)Passive Speaker (LHS-CX24

6、5W/LHS-CX247W) Type 1 Way 1 Speaker1 Way 1 Speaker Impedance 8 8 Frequency Response 130 - 20,000 Hz50 - 1,500 Hz Sound Pressure Level 85 dB/W (1m)82 dB/W (1m) Rated Input Power 25W60W Max Input Power 50W120W Net Dimensions (W x H x D) 90 x 138.5 x 100 mm160 x 350 x 345 mm Net Weight 0.9 kg4.5 kg 1-8

7、 Amplifier(LH-CX246) Stereo mode 25W + 25W (6 ohm at 1 kHz, THD 10%) Surround mode Front: 25W + 25W (THD 10%) Centre: 25W Surround: 25W + 25W (6 ohm at 1 kHz, THD 10%) Subwoofer: 60W (8 ohm at 30 Hz, THD 10%) Speaker Section(LH-CX246) Satellite Speaker (LHS-CX246T)Passive Speaker (LHS-CX246W) Type 1

8、 Way 1 Speaker1 Way 1 Speaker Impedance 8 8 Frequency Response 130 - 20,000 Hz50 - 1,500 Hz Sound Pressure Level 85 dB/W (1m)82 dB/W (1m) Rated Input Power 25W60W Max Input Power 50W120W Net Dimensions (W x H x D) 89 x 130 x 114 mm160 x 350 x 333 mm Net Weight 0.54 kg4.5 kg Amplifier(LH-CX640) Stere

9、o mode 90W + 90W (6 ohm at 1 kHz, THD 10%) Surround mode Front: 90W + 90W (THD 10%) Centre: 90W Surround: 90W + 90W (6 ohm at 1 kHz, THD 10%) Subwoofer: 150W (4 ohm at 30 Hz, THD 10%) Speaker Section(LH-CX640) Satellite SpeakerCentre speakerPassive Subwoofer (LHS-CX640T)(LHS-CX640C)(LHS-CX640W) Type

10、2 Way 2 Speaker2 Way 2 Speaker1 Way 1 Speaker Impedance6 6 4 Frequency Response120 - 20,000 Hz120 - 20,000 Hz40 - 1,500 Hz Sound Pressure Level82 dB/W (1m)82 dB/W (1m)83 dB/W (1m) Rated Input Power90W90W150W Max Input Power180W180W300W Net Dimensions (W x H x D)104 x 233 x 120 mm220 x 114 x 110 mm19

11、5 x 380 x 419 mm Net Weight1.0 kg1.0 kg6.6 kg Design and specifications are subject to change without notice. Manufactured under license from Dolby Laboratories. “Dolby” and the double-D symbol are trademarks of Dolby Laboratories. Confidential unpublished works. Copyright 1992-1997 Dolby Laboratori

12、es. All rights reserved. “DTS” and “DTS Digital Surround” are trademarks of Digital Theater Systems, Inc. 2-1 SECTION 2 CABINET SW 30Hz PAL:SW 25Hz Head switching output point RF Envelope output point Play the standard test tape. 6. X-distance Adjustment Left X-distance Adjusting Hole Tilt Adjusting

13、 Screw (C) Fixing Screw Height Adjusting Screw (B) Right Grove of Base A/C Purpose of adjustment : To maintain compatibility with other VCR (VCP). RF ENVELOPE OUTPUT POINT HEAD RF SWITCHING OUTPUT POINT OSCILLOSCOPE Connection Diagram CH-2CH-1 Azimuth Adjustment Screw(A) Checking/Adjustment Procedur

14、e 1) Play the blank tape (empty tape) and check whether the guide roller crumbles or wrinkles the tape and adjust it if necessary. 2) Check that the RF envelope output waveform is flat, and adjust the height of the guide roller while playing the standard test tape. 3) Adjust the switching point. 4)

15、Check the RF envelope output is the maximum when the tracking control locates at the center. If not maxi- mum, set up to ensure that RF envelope output becomes the maximum by turning the (+) type driver ( 3 4) on the base A/C groove. 4-18 DECK MECHANISM ADJUSTMENT 8-2. Check of Tape Curl and Jam Sta

16、tus Fixtures and tools usedConnection positionVCR (VCP) statusAdjustment position Oscilloscope Standard test tape (only for SP) Post Height Adjusting Driver Driver (+) Type 5 CH-1: PB RF Envelope CH-2: NTSC : SW 30Hz PAL:SW 25Hz Head switching output point RF Envelope output point Play the blank tap

17、e. Play the standard test tape. Fine adjustment of guide roller Switching Point Tracking Preset X-distance 7. Adjustment after Drum Assembly (Video Heads) Purpose of adjustment : To adjust and stabilize the height change, X-distance change, etc depending on the guide roller after assembling the drum

18、. RF ENVELOPE OUTPUT POINT V2V1V1 V1/V MAX = 0.7 V1/V MAX = 0.8 RF ENVELOPE OUTPUT HEAD RF SWITCHING OUTPUT POINT OSCILLOSCOPE Connection Diagram Waveform CH-2CH-1 Checking Procedure 1) Check that locking time of the RF and Audio waveform is fallen within the measuring standard in conversion of the

19、play mode from the CUE or the REV mode. 2) Readjust the paragraph 5 and 6 if it deviates from the standard. Fixtures and tools usedMeasuring standardConnection positionVCR (VCP) status Oscilloscope 6H 3KHz Color Bar Standard Test tape Stop Watch RF Locking Time: Within 5 seconds Audio Locking Time :

20、 Within 10 seconds CH-1: PB RF Envelope CH-2: Audio output RF Envelope output point Audio output jack Play the 6H 3KHz Color Bar Standard Test tape. 8. Check of Traveling Device after Deck Assembly 8-1. Audio, RF Normalization Time (Locking Time) Check in Play after CUE or REV Checking Procedure 1)

21、Check there is no abnormality of every traveling post status. 2) There must be no abnormal operation of the counter in occurrence of folding of the bottom tape. There must be not abnormality of audio signal in damage of the top tape. 3) If there is abnormality, readjust the adjustment para- graph 4

22、and 5. Fixtures and tools usedFixtures and tools usedFixtures and tools used T-160 Tape T-120 Tape There must be no jam or curl at the first, middle and end position of tape. Travel the tape at the position of its first and end. PROTECTION, MAINTENANCE AND CHECK OF VIDEO FUNCTION 4-19 (3) F/E Head (

23、5) Drum Assembly (Video Head) (4) Base Assembly P2 (2) Tension Post (1) Supply Reel (6) Base Assembly P3 Phenomena Replace- ment Checking Points and Cause Color beatPollution of Full-Erase Heado S/N, Color FadedPollution of Video Heado Horizontal, Vertical Jitteo CAUTIONS If operation of the positio

24、n with (O) mark is abnormal even after removing cause, replace it with substitute product since it shows damage or wearing. (7) A/C Head (8) P4 Post (10) Pinch Roller (11) Take-up Guide Post (9) Capstan Shaft (12) Take-up Reel * No. (1) (12) shows sequence that the tape moves from the supply reel to

25、 the take-up reel.) Fig. C-9-1 TOP VIEW Fig. C-9-2 BOTTOM VIEW F/E Head Video Head A/C Head Pinch Roller Belt Capston Clutch Assembly A37 Fig. C-9-3 Tape Transport System Pollution of Video Head or Tape Transport System Poor Sound, Low Soundo Pollution of Audio/Control Head o Pollution of Pinch Roll

26、er or Belt Capstan Belt No tape wound or tape wound loosely. FF or REW impossible, or slow turning Deterioration of Clutch Assembly D37 Torque Pollution of Drum and Traveling Device Tape loosely wound in REV or Unloading o Fig. C-9-3 1. Checking Points prior to Repair Following abnormal phenomena ma

27、y be repaired by removal of foreign materials and oil supply. Check oiling is required at the checking set or cleaning status is complete. Determine that necessity of checking and repair the set exists after checking the using period of the set together with the user. In this case, followings must b

28、e checked: PROTECTION, MAINTENANCE AND CHECK OF VIDEO FUNCTION 4-20 2. Essential Check and Repair Recording density of the video is far higher than the audio. Therefore video parts are very precise so as to allow only error of 1/1000mm or so in order to maintain compatibility with other videos. If o

29、ne of these parts is polluted or old, same phenomena will appear as they are damaged. To maintain clear screen, regular check, replacement of old and damaged parts and oil supply, etc are essential. 3. Regular Check and Repair Check and repair schedule is not constant since they vary depending on me

30、thod that the consumer uses video and environment where the video is installed at. However, for the video used by common household, good screen will be maintained if regular check and repair per 1,000 hour is performed. The following chart shows relation- ship between using time and checking time: 4

31、. Tools for Check and Repair (1) Grease: Floil G-3114 (KANTO) or equivalent grease (Green) (2) Grease: Kanto G-754, PL-433 (Yellow) (3) Alcohol (Isopropyl Alcohol) (4) Cleaning Patch (cloth) 5. Maintenance Process 5-1) Removal of Foreign Material (1) Removal of foreign material from video head (Fig.

32、 C-9-4) Firstly try to use a cleaning tape. (1) Use a cleaning patch if foreign materials are not removed with the cleaning tape due to severe dirty of the head. Soak the cleaning patch in alcohol and put it to the head tip. Smoothly turn the drum (turning cylinder) to the right or left (In this cas

33、e, the cleaning patch must not be moved vertically). (1) After completely drying the head, test the traveling status of the tape. (1) If alcohol (Isopropyl Alcohol) remains at the video head, the tape may be damaged when this solution touches with the head surface. Never use a cloth bar (commercial

34、sale) (2) Wipe the tape transport system and the drive system with the cleaning patch soaked in alcohol (Isopropyl Alcohol) when removing foreign materials from them. 1) The part touched with the traveling tape is called as tape transport system. The drive system consists of parts to travel the tape

35、. (2) 2) Care must be exercised so that unreasonable force to change the pattern will be applied to the tape trans- port system during removal of foreign materials. About 1 year One hour Table 1 Two hours Three hours Time Requiring Checking Average hours used per day About 18 months About 3 years Fi

36、g. C-9-4 Drum (Turning Cylinder) Head Tip Soak alcohol (Isopropyl Alcohol). Cleaning Patch (Cloth) Smoothly turn the drum (turning cylinder) touching the soft surface to the head tip surface. PROTECTION, MAINTENANCE AND CHECK OF VIDEO FUNCTION 4-21 5-2) Grease Applications (1) Grease Application Met

37、hod Apply grease by using a cloth swab or brush. Care must be exercised so that excess quantity should not be used. If the excessive quantity is applied, wipe it with the gauze soaked in alcohol (Isopropyl Alcohol). NOTE: POSITION OF GREASE APPLICATION (2) Regular Grease Application Apply grease to

38、the designated application position every 500 hour. 5 4 2 1 3 (1) Inner Side Surface and Top Surface of Loading Path (2) Stable Adhesion Part of Base P2, P3 (3) Arm Pinch Shaft (4) Gear Wheel Shaft (5) Reel S. T. Shaft (1) (2) (3) (4): KG-684G (Green) (5): PL-433 (Yellow) Cam Part (PL-433.Yellow) Ge

39、ar Part (PL-433.Yellow) Boss Part Side Wall (PL-433.Yellow) Gear Part Side Application (PL-433.Yellow) Cam Part Side Application (KG-684G.Green) Gear SectorGear Cam Base LoadingGear Drive Inner Surface of Guide Rail (KG-684G.Green) Chassis (L)Chassis (R) Gear Part 1 2 3 4 6 5 7 (1) Inner Side Surfac

40、e and Top Surface of Loading Path (2) Stable Adhesion Part of Base P2, P3 Coil (3) Gear Cam Shaft (4) Gear Drive Shaft (5) Clutch Shaft Groove (6) Guide Part on the Plate Slider Side Wall (Left) (7) Guide Part on the Plate Slider Side Wall (Right) (1) (2) (3) (4) (5) (6) (7): KG- 684G (Green) Chassi

41、s (TOP) Chassis (Bottom) Cam Part (KG-684G , GREEN) Cam Part (KG-684G , GREEN) Gear Rack F/L Lever, Brake Driving Cam Part Side Wall Guide Part Lever F/R Driving Part Side Wall Guide Part Lever, Spring Driving Part Lever Tension Driving Cam Part Gear Sector Driving Part Plate Slider PROTECTION, MAIN

42、TENANCE AND CHECK OF VIDEO FUNCTION 4-22 Lever, F/R, Base, TensionGEAR AY, P2 & P3 LEVER, F/R Clutch Contact Part (PL-433, Yellow) Tension Arm Party Hinge Part (PL-433, Yellow) BASE, TENSION PL-433 MECHANISM TROUBLESHOOTING GUIDE 4-23 No Auto Rewind operates. Is output of the end sensor “H”? “H”: 3.

43、5V or less “L”: 0.7V 1V or less Is voltage at both ends of the IR LED 0.8V-1.5? Replace the LED. Is the end sensor Vcc applied at 5V? Check the Syscon power supply. Replace the end sensor. Is the Syscon checked? NO YES YES YES YES NO NO 1.Deck Mechanism A. NO NO NO No F/R operates. Is the current mo

44、de an F/R mode? Check the assembly position of the Mode S/W. Is normal voltage applied at the Vcc1 and the Vcc2 of the Capstan motor? Is the Vctl terminal voltage of the Capstan Motor applied at more than 4V? Check the Servo, Power circuit. Replace the Capstan motor. Does the Capstan motor rotate? D

45、oes the T/up and the supply reel Operate? Check the Syscon circuit. YES YES YES YES YES YES B. 4-24 MECHANISM TROUBLESHOOTING GUIDE Auto Stop operates. (PLAY/CUE/REV) Does the T/UP or the supply reel pulse occur? Does the pinch roller attached to the Capstan shaft turn in opera- tion of the Play/Cue

46、/Rev. Replace the reel sensor. Is output of the DFG, DPG normal? Check the assembly mode. Check the spring pinch. Replace the drum motor. Check the Servo, Syscon. Check the Syscon, -com. No cassette loading is done. Insert the cassette. Check the holder assembly CST. Does output of the CST IN S/W ch

47、ange? (In insertion of the REC tape: “L”_“H”_ “L”) (In insertion of the REC preven- tion tape: “L”_ “H”_ “L”_ “H”) Is the CST IN S/W normal? Is operation of the lever assembly S/W normal? Check the Syscon circuit. Check the Syscon circuit. Replace the CST IN S/W. YES YES YES YES YES YES NO NO NO NO

48、NONO NO YES C. D. 4-25 MECHANISM TROUBLESHOOTING GUIDE No tape winding is done in play. Is the pinch roller attached to the Capstan shaft in operation of play? Check the assembly mode? Does the T/up reel operate? Hang the Capstan belt. Is the Capstan belt hung? Does the drum motor turn? Is the DPG,

49、DFG normal? Are the T/up and the reel sensor normal? Check the Syscon circuit. Check the Syscon circuit. Check the Syscon circuit. Does the Capstan motor turn? Is the Vctl terminal voltage of the drum motor at more than 2.3V? Replace the drum motor. Is the Vcc voltage of the drum motor normal? Check the clutch and the idler assembly. YES YES YES YES YES YES YES YES NO NO NO NO NO Is the Vctl terminal voltage of the Capstan motor applied at more than 4V? Replace the Capstan motor. Is normal voltage applied to the capstan motor V