Zenith-LX140-cs-sm电路图 维修手册.pdf

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1、MICRO COMPONENT RadioFans.CN 收音机爱 好者资料库 - 1-1 - CONTENTS SECTION 1. GENERAL SERVICING PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 ESD PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2、. . . . . . . . . 1-4 SPECIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5 SECTION 2. ELECTRICAL ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3、 . 2-1 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 WAVEFORMS OF MAJOR CHECK POINT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11 BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . .

4、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21 SCHEMATIC DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23 WIREING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5、. . . . . . 2-31 PRINTED CIRCUIT DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32 INTERNAL BLOCK DIAGRAM OF ICs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-39 SECTION 3. EXPLODED VIEWS CABINET AND MAIN FRAME SEC

6、TION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1 SECTION 4. SPEAKER SPEAKER PART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1 SECTION 5. REPLACEMENT PARTS LIST REPLACEMENT PARTS LIST . .

7、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1 RadioFans.CN 收音机爱 好者资料库 - 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 ba

8、g until immediately prior to use. 2) The pick-up should never be subjected to external pressure or impact. 2. Repair notes 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

9、care to avoid external pressure and impact. If it is subjected to strong pressure or impact, the result may be an operational 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 adju

10、stment point and installation screws should absolutely never 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 surface If th

11、ere is dust on the lens surface, the dust should be cleaned away by using an air bush (such as used for camera lens).The 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 pi

12、ck-up. Spring by excess pressure. If the lens is extremely dirty, 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 much of this alcohol on the swab, and do not allow the alcohol to get inside the pick-up.

13、Storage in conductive bagDrop impact NEVER look directly at the laser beam, and dont let contact fingers or other exposed skin. Magnet How to hold the pick-up Conductive Sheet Cotton swab Pressure Pressure RadioFans.CN 收音机爱 好者资料库 - 1-3 - NOTES REGARDING COMPACT DISC PLAYER REPAIRS 1. Preparations 1)

14、 Compact disc players incorporate a great many ICs as well as the pick-up (laser diode).These components are sensitive 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)

15、 The pick-up is composed of many optical components and other high-precision components. Care must be taken, 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 repair 1) Before replacing

16、 a component part, first disconnect the power supply lead wire from the unit 2) 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

17、on the bag. (This is because there is the possibility of damage by static 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

18、 clothing, in order to prevent sta- tic electricity changes in the clothing to escape from the armband. 7) The laser beam 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, di

19、splay, etc.). Using a pointed good conductor(such as driver), simply short the RESET jump wire on the inside of the volume 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 kn

20、ob and release it. 2. If you wish to operate the RESET jump wire, it is necessary to unplug the power cord. Resistor (1 Mohm) Conductive Sheet Resistor (1 Mohm) Armband RESET jump wire VOLUME VOLUME KNOB DOWN UP - 1-4 - ESD PRECAUTIONS Electrostatically Sensitive Devices (ESD) Some semiconductor (so

21、lid state) devices can be damaged easily by static electricity. Such components commonly are called Electrostatically Sensitive Devices (ESD). Examples of typical ESD devices are integrated circuits and some field-effect transistors and semiconductor chip components.The following techniques should b

22、e used to help reduce the incidence of 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 comm

23、ercially available discharging wrist strap 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 ESD devices, place the assembly on a conductive sur- face such as aluminum foil, to prevent el

24、ectrostatic charge buildup or exposure of the assembly. 3. Use 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 can generate electrical charges sufficient to damage ESD de

25、vices. 5. Do not use freon-propelled chemicals.These can generate electrical charges sufficient to damage 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 ele

26、ctrically shorted together by conductive foam, aluminum foil or comparable conductive materials). 7. Immediately 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 installe

27、d. CAUTION : BE SURE NO POWER IS APPLIED TO THE CHASSIS OR CIRCUIT, AND OBSERVE ALL OTHER SAFETY PRECAUTIONS. 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

28、 carpeted floor can gen- erate static electricity sufficient to damage an ESD device). CAUTION. GRAPHIC SYMBOLS THE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHIN AN EQUILATERAL TRIANGLE, IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF UNINSULATED “DANGER- OUS VOLTAGE” THAT MAY BE OF SU

29、FFICIENT MAGNITUDE TO CONSTITUTE A RISK OF ELECTRIC SHOCK. THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIANGLE IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN SERVICE LITERATURE. - 1-5 - SPECIFICATIONS - 1-6 - MEMO - 2-1 - SECTION 2. ELECTRICAL ADJUSTME

30、NTS This set has been aligned at the factory 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 any- one tampers with the adjustment, realignment may be necessary. IMPORTANT 1. Check

31、 Power-source voltage. 2. Set the function 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 ac

32、tion. TAPE DECK ADJUSTMENT 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 1. AZIMUTH ADJUSTMENT 2.TUNER ADJUSTMENT Figure 1. Azimuth Adjustment Connection Diagram Deck Mode Test Tape Test Point Adjustment Adjust fo

33、r Palyback MTT-114 Speaker Out DECK Screw Maximum Azimuth Screw Head Playback Mode Unit Speaker Out GND L out R out Record/Playback head Test Tape MTT-111 Frequency Counter Figure 1. Azimuth Adjustment Connection Diagram Item Test Point Adjustment Adjust for DC Voltage Check point TP1, TP2DECK Screw

34、 0V 50mV - 2-2 - CD PART TROUBLESHOOTING - 2-3 - OPEN CLOSE NG - 2-4 - “ READING ” DISPLAY CHECK (= ONLY “CD “DISPLAY) - 2-5 - READING OK CHECK (= “NO DISC” DISPLAY) - 2-6 - READING OK CHECK #A (= “NO DISC” DISPLAY) - 2-7 - READING OK CHECK #B (= “NO DISC” DISPLAY) - 2-8 - READING OK CHECK #C (= “NO

35、 DISC” DISPLAY) - 2-9 - READING OK CHECK #D (= “NO DISC” DISPLAY) - 2-10 - READING OK CHECK # E (= “NO DISC” DISPLAY) - 2-11 - WAVEFORMS OF MAKOR CHECK POINT - 2-12 - #4. SPINDLE DRIVE AND MOTOR WAVEFORM (IC503 pin6, 1 2) when TOC reading #5. TRACK DRIVE AND MOTOR WAVEFORM (TP560, IC503 pin23) durin

36、g normal play #6. RF, TRACKING AND FOCUS ERROR WAVEFORM (IC502 pin8, 2 1 , 23) during normal play - 2-13 - AUDIO PART - 2-14 - - 2-15 - - 2-16 - - 2-17 - FM(TU101) Troubleshooting Check the 12V input of TU101 pin6 Check the “High” of TU101 Pin5 Check the 12V of Q102 “E” Check the Power circuit Refer

37、 to “IC103 Troubleshooting” Check the “LOW” of IC103 pin7 Replace the Q102 Replace the TU101 Check the OSC waveform of TU101 pin8 Refer to “IC102 Troubleshooting” YES YES YES YES YES NO NO NO IC102 Troubleshooting Check the power input of IC102 pin8 Check the wavefor of IC102 Pin20, 21 Refer to “Pow

38、er Troubleshooting” Check the FM(TU101), AM(L102) Replace the IC102 Check the “LOW” of IC102 Pin 13 Replace the IC103 Refer to “IC103 Troubleshooting” Check the waveform output IC102 pin 16, 17 END YES YES YES NO NO NO - 2-18 - IC103 Troubleshooting AM COIL Troubleshooting Check the Power input of I

39、C103 pin17 X104 oscillation Refer to “Power Troubleshooting” Repleace the X104 Repleace the IC103 Refer to “IC103 Troubleshooting” CE: Chip Enable DI: Data Input (from u-com) DO: Data Output (to u-com) CLK:Tuner mode clock Check the Clock of CE, DI, DO, CLK Check the operation END YES YES YES YES NO

40、 NO NO NO Check the “High” of L102 Pin2 Check the oscillation the L102 pin 13 Check the IC102 Troubleshooting Refer to “IC103 Troubleshooting” Replace the L102 YES NO - 2-19 - PLAY Check the B+ Power to LEAF Switch Checks the B+ power to Q201 “E” Check the CN901 pin8, 9 and IC903 output Check the si

41、gnal to IC202 pin4, 11 Check the SW201 and HEAD connector Check the output to speaker Check the CN202 Check the CN201 YES YES YES YES NO NO NO REC Check the signal input of IC201 pin4, 11 Check the of CN201 pin4, 5 Check the oscillation of L201 Check the signal input to PN201 pin8, 9 Check the HEAD

42、connector Check the B+ of LEAF switch Check the R218, L201, L204 YES YES YES NO NO NO - 2-20 - MEMO BLOCK DIAGRAM 2-212-22 2-232-24 SCHEMATIC DIAGRAMS FRONT/POWER SCHEMATIC DIAGRAM 2-252-26 MAIN/DECK SCHEMATIC DIAGRAM 2-272-28 TUNER SCHEMATIC DIAGRAM 2-292-30 CDP SCHEMATIC DIAGRAM 2-312-32 WIRING DI

43、AGRAM 2-332-34 PRINTED CIRCUIT DIAGRAMS FRONT P.C. BOARD 2-352-36 MAIN P.C. BOARD 2-372-38 CDP P.C. BOARD - 2-39 - INTERNAL BLOCK DIAGRAM OF ICs I IC300 LC87F73C8A 1) Pin Assignment - 2-40 - I IC601 TDA7468D 1) BLOCK DIAGRAM - 2-41 - 2) PIN CONNECTION - 2-42 - I IC301 BU1923 1) BLOCK DIAGRAM ? ? ? ?

44、 ? ? ? ? ? ? - 2-43 - I IC102LA1837 1) BLOCK DIAGRAM I IC102LA1837 2) Test Circuit Diagram - 2-44 - I IC103 LC72131D 1) Pin Assignments - 2-45 - I IC201 AN7312 1) BLOCK DIAGRAM I IC701 LA4631 1) BLOCK DIAGRAM - 2-46 - I IC504 M12L16161A 1) Synchronous DRAM PIN Definitions PINNAMEINPUT FUNCTION CLKSy

45、stem ClockActive on the positive going edge to sample all inputs. CSChip Select Disables or enables device operation by masking or enabling all inputs except CLK, CKE and L(U)DQM. CKEClock EnableMasks system clock to freeze operation from the next clock cycle. CKE should be enabled at least one cycl

46、e prior to new command. Disable input buffers for power down in standby. A0A10/APAddressRow/column addresses are multiplexed on the same pins. Row address: RA0 RA10, column address : CA0CA7 BABank Select AddressSelects bank to be activated during row address latch time. Selects bank for read/write d

47、urring column address latch time. RASRow Address Strobe Latches row addresses ont eh positive going edge of the CLK with RAS low. CASColumn Address StrobeLatches column addresses on the positive going edge of the CLK with CAS low. Enables column access. WEWrite EnableEnalbes write operation and row

48、precharge. Latches data in starting form CAS, WE active. L(U)DQMData Input/Output MaskMakes data output Hi-z, tSHZ after the clock and masks the out- put. Blocks data input when L(U) DQM active. 3-13-2 CABINET AND MAIN FRAME SECTION SECTION 3. EXPLODED VIEWS A43 450 260 261 262 A46 282 281 A43 305 2

49、80 451 451 451 A46 295 294 293 291 292 290 A00 251 254 253 250 255 256 257 258 A40 266 266 270 252 268 267 269 NOTE) Refer to “SECTION 5 REPLACEMENT PARTS LIST” in order to look for the part number of each part. Caution point A43: Front + Power Array Assembly. A46: Main + TP Deck + Tuner Array Assembly. - 4-1 - SECTION 4. SPEAKER SECTION MODEL: LXS-M140 855 854 853 852 851 861 850 850 - 4-2 - MEMO