LG-LHTK250-cdr-sch 维修电路原理图.pdf
《LG-LHTK250-cdr-sch 维修电路原理图.pdf》由会员分享,可在线阅读,更多相关《LG-LHTK250-cdr-sch 维修电路原理图.pdf(54页珍藏版)》请在收音机爱好者资料库上搜索。
1、1-1CONTENTSSECTION 1. GENERAL SERVICING PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 ESD PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 SPECIFICATIONS . . . . . .
2、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5SECTION 2. AUDIO PART AUDIO TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . .
3、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4 SCHEMATIC DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6 WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4、 . . . . 2-20 PRINTED CIRCUIT DIARGAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22SECTION 3. DVD & AMP PART ELECTRICAL TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1 DVD PART SCHEMATIC DIAGRAMS . . . . .
5、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-22SECTION 4. EXPLODED VIEWS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1SECTION 5. SPEAKER PART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1SECTION 6. REPLACEME
6、NT PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1RadioFans.CN 收音机爱 好者资料库1-2SERVICING PRECAUTIONSNOTES REGARDING HANDLING OF THE PICK-UP1. Notes for transport and storage1) The pick-up should always be left in its conductive bag until immediately prior to use.2) The pick-up s
7、hould never be subjected to external pressure or impact.2. Repair notes1) 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 andimpact. If it is s
8、ubjected to strong pressure or impact, the result may be an operational malfunction and/ordamage to the printed-circuit board.3) Each and every pick-up is already individually adjusted to a high degree of precision, and for that reasonthe adjustment point and installation screws should absolutely ne
9、ver be touched.4) Laser beams may damage the eyes!Absolutely 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 surfaceIf there is dust on the lens surface, the dust should be cleaned aw
10、ay by using an air bush (such as usedfor camera lens). The lens is held by a delicate spring. When cleaning the lens surface, therefore, a cot-ton 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 dirt
11、y, apply isopropyl alcohol to the cotton swab. (Do not use any other liquid cleaners, because they will damage the lens.) Take care not to use too muchof this alcohol on the swab, and do not allow the alcohol to get inside the pick-up.Storage in conductive bagDrop impactNEVER look directly at the la
12、ser beam, and dont let contact fingers or other exposed skin.MagnetHow to hold the pick-upConductive SheetCotton swabPressurePressureSECTION 1. GENERALRadioFans.CN 收音机爱 好者资料库1-3NOTES REGARDING COMPACT DISC PLAYER REPAIRS1. Preparations1) Compact disc players incorporate a great many ICs as well as t
13、he pick-up (laser diode). These componentsare sensitive to, and easily affected by, static electricity. If such static electricity is high voltage, componentscan be damaged, and for that reason components should be handled with care.2) The pick-up is composed of many optical components and other hig
14、h-precision components. Care must betaken, therefore, to avoid repair or storage where the temperature of humidity is high, where strong magnet-ism is present, or where there is excessive dust.2. Notes for repair1) Before replacing a component part, first disconnect the power supply lead wire from t
15、he unit2) All equipment, measuring instruments and 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 isbecause there is the possibility of damage by static
16、 electricity.)4) To prevent AC leakage, the 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 preventstatic electricity changes in the clothing to
17、escape from the armband.7) The laser beam from the pick-up should NEVER be directly facing the eyes or bare skin.Resistor(1 Mohm)ConductiveSheetResistor(1 Mohm)Armband1-4ESD PRECAUTIONSElectrostatically Sensitive Devices (ESD)Some semiconductor (solid state) devices can be damaged easily by static e
18、lectricity. Such componentscommonly are called Electrostatically Sensitive Devices (ESD). Examples of typical ESD devices are integratedcircuits and some field-effect transistors and semiconductor chip components. The following techniques shouldbe used to help reduce the incidence of component damag
19、e caused by static electricity.1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain offany electrostatic charge on your body by touching a known earth ground. Alternatively, obtain and wear acommercially available discharging wrist strap device, which
20、should be removed for potential shock reasonsprior to applying power to the unit under test.2. After removing an electrical assembly equipped with ESD devices, place the assembly on a conductive surfacesuch as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.3. Use
21、only a grounded-tip soldering iron to solder or unsolder ESD devices.4. Use only an anti-static solder removal device. Some solder removal devices not classified as anti-static cangenerate electrical charges sufficient to damage ESD devices.5. Do not use freon-propelled chemicals. These can generate
22、 electrical charges sufficient to damage ESDdevices.6. Do not remove a replacement ESD device from its protective package until immediately before you areready to install it. (Most replacement ESD devices are packaged with leads electrically shorted together byconductive foam, aluminum foil or compa
23、rable conductive materials).7. Immediately before removing the protective material from the leads of a replacement ESD device, touch theprotective 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
24、OBSERVE ALL OTHERSAFETY PRECAUTIONS.8. Minimize bodily motions when handing unpackaged replacement ESD devices. (Otherwise harmless motionsuch as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can gener-ate static electricity sufficient to damage an ES
25、D device).CAUTION. GRAPHIC SYMBOLSTHE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHIN AN EQUILATERAL TRIANGLE, ISINTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF UNINSULATED “DANGEROUS VOLTAGE” THAT MAY BE OF SUFFICIENT MAGNITUDE TO CONSTITUTE A RISK OF ELECTRIC SHOCK.THE EXCLAMATION POINT W
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- LG-LHTK250-cdr-sch 维修电路原理图 LG LHTK250 cdr sch 维修 电路 原理图