LG-FFH976-cs-sp 电路图 维修手册.pdf

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1、- 1-2 - SECTION 1. GENERAL SERVICING PRECAUTIONS NOTES REGARDING HANDLING OF THE PICK-UP 1. Notes for transport and storage 1) The pick-up should always be left in its conductive bag until immediately prior to use. 2) The pick-up should never be subjected to external pressure or impact. 2. Repair no

2、tes 1) The pick-up incorporates a strong magnet, and so should never be brought close to magnetic materials. 2) The pick-up should always be handled correctly and carefully, taking care to avoid external pressure and impact. If it is subjected to strong pressure or impact, the result may be an opera

3、tional malfunction and/or damage to the printed-circuit board. 3) Each and every pick-up is already individually adjusted to a high degree of precision, and for that reason the adjustment point and installation screws should absolutely never be touched. 4) Laser beams may damage the eyes! Absolutely

4、 never permit laser beams to enter the eyes! Also NEVER switch ON the power to the laser output part (lens, etc.) of the pick-up if it is damaged. 5) Cleaning the lens surface If there is dust on the lens surface, the dust should be cleaned away by using an air bush (such as used for camera lens). T

5、he lens is held by a delicate spring. When cleaning the lens surface, therefore, a cotton swab should be used, taking care not to distort this. 6) Never attempt to disassemble the pick-up. Spring by excess pressure. If the lens is extremely dirty, apply isopropyl alcohol to the cotton swab. (Do not

6、use any other liquid cleaners, because they will damage the lens.) Take care not to use too much of this alcohol on the swab, and do not allow the alcohol to get inside the pick-up. Storage in conductive bagDrop impact NEVER look directly at the laser beam, and dont let contact fingers or other expo

7、sed skin. Magnet How to hold the pick-up aPressure Pressure Cotton swab Conductive Sheet RadioFans.CN 收音机爱 好者资料库 - 1-3 - NOTES REGARDING COMPACT DISC PLAYER REPAIRS 1. Preparations 1) Compact disc players incorporate a great many ICs as well as the pick-up (laser diode). These components are sensiti

8、ve to, and easily affected by, static electricity. If such static electricity is high voltage, components can be damaged, and for that reason components should be handled with care. 2) The pick-up is composed of many optical components and other high-precision components. Care must be taken, therefo

9、re, to avoid repair or storage where the temperature of humidity is high, where strong magnetism is present, or where there is excessive dust. 2. Notes for repair 1) Before replacing a component part, first disconnect the power supply lead wire from the unit 2) All equipment, measuring instruments a

10、nd tools must be grounded. 3) The workbench should be covered with a conductive sheet and grounded. When removing the laser pick-up from its conductive bag, do not place the pick-up on the bag. (This is because there is the possibility of damage by static electricity.) 4) To prevent AC leakage, the

11、metal part of the soldering iron should be grounded. 5) Workers should be grounded by an armband (1M) 6) Care should be taken not to permit the laser pick-up to come in contact with clothing, in order to prevent static electricity changes in the clothing to escape from the armband. 7) The laser beam

12、 from the pick-up should NEVER be directly facing the eyes or bare skin. CLEARING MALFUNCTION You can reset your unit to initial status if malfunction occur(button malfunction, display, etc.). Using a pointed good conductor(such as driver), simply short the RESET jump wire on the inside of the volum

13、e knob for more than 3 seconds. If you reset your unit, you must reenter all its settings(stations, clock, timer) NOTE: 1. To operate the RESET jump wire, pull the volume rotary knob and release it. 2. If you wish to operate the RESET jump wire, it is necessary to unplug the power cord. Armband Cond

14、uctive Sheet Resistor (1 Mohm) Resistor (1 Mohm) VOLUME KNOB UP DOWN VOLUME RESET jump wire RadioFans.CN 收音机爱 好者资料库 ESD PRECAUTIONS Electrostatically Sensitive Devices (ESD) Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called Elec

15、trostatically Sensitive Devices (ESD). Examples of typical ESD 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 be

16、fore 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 strap device, which should be removed for potential shock reasons

17、prior to applying power to the unit under test. 2. After removing an electrical assembly equipped with ESD 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 sold

18、er or unsolder ESD 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 ESD devices. 5. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damag

19、e ESD devices. 6. Do not remove a replacement ESD device from its protective package until immediately before you are ready to install it. (Most replacement ESD devices are packaged with leads electrically shorted together by conductive foam, aluminum foil or comparable conductive materials). 7. Imm

20、ediately before removing the protective material from the leads of a replacement ESD device, touch the protective material to the chassis or circuit assembly into which the device will by installed. CAUTION : BE SURE NO POWER IS APPLIED TO THE CHASSIS OR CIRCUIT, AND OBSERVE ALL OTHER SAFETY PRECAUT

21、IONS. 8. Minimize bodily motions when handing unpackaged replacement ESD devices. (Otherwise 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 sufficient to damage an ESD device). - 1-4 - RadioFans.C

22、N 收音机爱 好者资料库 - 1-5 - SPECIFICATIONS 1. AMP SECTION 1) Power Output (6 , 2 channel, T.H.D. 10%) .30W+30W 120W+120W 2) T.H.D 0.2% .0.2% 1.0% 3) Frequency Response (-3dB down) .700Hz25kHz 45Hz700Hz 4) Signal-to-noise Ratio .85dB 75dB 5) Input Sensitivity AUX .40050mV 40050mV 6) Channel Difference 1kHz

23、.2dB- 2. TUNER SECTION 1) FM/OIRT 1) Frequency Range . 87.5MHz108MHz or 65.0MHz74.0MHz & 87.5MHz108MHz 2) Intermediate Frequency. 10.7MHz 3) Sensitivity (70MHz/78.6MHz/83.0MHz/86.6MHz/90MHz/98MHz). 12dB 4) Signal-to-noise Ratio 98.1MHz(Mono/Stereo). 61dB/58dB 5) Image Rejection 106.1MHz. 20dB 6) IF

24、Rejection 90.1MHz . 65dB 7) Distortion 98.1MHz(Mono/Stereo). 1.2/1.2% 8) Frequency Response (-3dB) . 60Hz10kHz 9) Stereo Separation (100Hz/1kHz/10kHz). 23dB 2) AM(MW) 1) Frequency Range . 522kHz1611kHz/530kHz1610kHz/530kHz1720kHz 2) Intermediate Frequency. 450kHz 3) Usable Sensitivity. 55dB 4) Image

25、 Rejection (1404kHz) . 25dB 5) IF Rejection (603kHz). 40dB 6) Selectivity (1008kHz). 23dB 7) Signal-to-noise Ratio (1008kHz). 35dB 8) Distortion (1008kHz) . 1.5% 9) Frequency Response (1008kHz). 100Hz1800Hz 3) SW(OPTIONAL) 1) Frequency Range. 5.8MHz18MHz 2) Intermediate Frequency. 450kHz 3) Usable S

26、ensitivity. 40dB 4) Signal To Noise Ratio. 35dB 5) Distortion . 3% 4) LW(OPTIONAL) 1) Frequency Range . 153kHz281kHz 2) Intermediate Frequency. 450kHz 3) Usable Sensitivity. 65dB 4) Signal To Noise Ratio (200kHz). 28dB 5) Distortion (200kHz) . 3% Main Super Woofer - 1-6 - 3. TAPE DECK SECTION 1) Tap

27、e Speed (MTT-111) / Normal Speed . 4.75(+2%, -1%)cm/sec 2) Wow Flutter (MTT-111) . 0.25% 3) Fast Forward and Rewind Time (C-60) . 120sec 4) Frequency Response (6dB range) . 125Hz8kHz 5) Signal-to-noise Ratio (Playback/Record). 43dB/43dB 6) Distortion (Playback/Record). 3% / 4% 7) Crosstalk (Playback

28、: 1kHz). 55dB 8) Channel Separation (Playback: 1kHz). 50dB 9) Erase Ratio. 55dB 4. COMPACT DISC PLAYER SECTION 1) Frequency Response (200Hz-18kHz) . +0.5/-3.0dB 2) Signal-to-noise Ratio (1kHz). 70dB 3) Dynamic Range (1kHz). 70dB 4) T.H.D. (1kHz). 0.2% 5) Separation (100Hz/1kHz/10kHz). 45dB/45dB/40dB

29、 6) Access Time Short / Long. 2sec/5sec 5. GENERAL 1) Power requirement. Refer to the back panel of unit 2) Power consumption . 170W 3) Dimension (W x H x D). 273 x 326 x 360 (mm) 4) Weight (net). 9.1kg NOTE : Specification are subject to change without notice in the course of product improvement. -

30、 2-1 - TAPE DECK ADJUSTMENT 1. AZIMUTH ADJUSTMENT Figure 1. Azimuth Adjustment Connection Diagram CH1 CH2 Speaker Out Playback Mode Head Test Tape MTT-114 L ch R ch GND Dual-trace synchroscope Electronic Voltmeter L out R out Unit SECTION 2. ELECTRICAL ADJUSTMENTS This set has been aligned at the fa

31、ctory and normally will not require further adjustment. As a result, it is not recommended that any attempt is made to modificate any circuit. If any parts are replaced or if anyone tampers with the adjustment, realignment may be necessary. IMPORTANT 1. Check Power-source voltage. 2. Set the functio

32、n switch to band being aligned. 3. Turn volume control to minimum unless otherwise noted. 4. Connect low side of signal source and output indicator to chassis ground unless otherwise specified. 5. Keep the signal input as low as possible to avoid AGC and AC action. Deck ModeTest TapeTest PointAdjustmentAdjust for A Deck PlaybackMTT-114Speaker Out DECK Screw Maximum Azimuth Screw B Deck PlaybackMTT-114Speaker OutAzimuth ScrewMaximum 2. MOTOR SPEED ADJUSTMENT Figure 2. Motor Speed Adjustment Connection