Vieta-VMD55USB-cs-sm 电路图 维修手册.pdf

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1、Service manual?VMD55USB? contents 1? Debug element scheme -1 2? Triode integrated circuit outside drawing -2 3? Malfunction follow check list -3-4 4? ltems lf safety attention -5-7 5?PCB layout-8-11 6?Elements layout -12-13 7?-14 8?Wiring diagram-15 9?Exploded view-16-17 10?Electronic specification-

2、18-22 11?Part list-23-38 This service manual is just for your reference(it just contains a little service contents and items of safety attention,And the use of technical service is up to the service level of repairman himself),If any changes we wont inform. RadioFans.CN 收音机爱 好者资料库 FM receiver freque

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4、n t e g r a t e d c i r c u i t o u t s i d e d r a w i n g FOLLOW-UP FAULT RECORD CHART Check if the sound source (speaker) is good or not? Confirm to change the speaker or output wire no yes Make sure to change the transformer of power supply and the power commutate circuit. No sound is heard for

5、radio reception Check if the DVD output is good or not? Check if the radio reception circuit IC 1823 and the component around it is regular or not? yes no Check the public circuit and power circuit. no Check the radio reception controled circuit yes Check if the power supply circuit of radio recepti

6、on is regular or not? no yes yes no yes Check if the output public circuit?amplified circuit is good or mt for the whole unit no yes Check if the power supply circuit is good or not? no ? ? yes Check the amplified integrate circuit 7265 and change it. Make sure to change the IC 1823 and the componen

7、t around it Make sure to change the concerned component of radio reception controled circuit. no no yes Make sure to change the concerned component of power supply circuit ? No sound is heard for DVD Check if the output of radio reception is good or not? Check the public circuit?power circuit and ch

8、ange the concerned component Check if the DVD controled circuit is good or not? Make sure to change the concerned component of DVD controled circuit Check the concemed components?row wire ?sockets of DVD signal channel? Make sure to change the concerned components?row wire?sockets of DVD . Change th

9、e decode board. No sound is heard for the whole unit. 3 M a l f u n c t i o n f o l l o w c h e c k l i s t no no no no no no no ye No search for DVD Check if power supply of decode board +3v?+5v is regular or not? Check the stable voltage. Check if the light head component can give out light regula

10、r or not? The decode board is broken. Check if the light head component row wire is loose or not? Check and change the betler light head row wire. The lithting head component is broken. No picture for DVD Check if the audio video socket?video line is regular or not? The decode board is broken. Make

11、sure to change the video line and socket. 4 M a l f u n c t i o n f o l l o w c h e c k l i s t SAFETY ATTENTION Common Controlling During maintenance, please take common controlling to protect component system and electronic parts and prevent damages to the circuit due to improper operation . led o

12、ut wire should be kept away from high-pressure or high-temperature parts. MAINENANCE ATTENTION Attention: please read ?SAFETY ATTENTION? carefully. If there are unexpected conflicts between safety attention and maintenance attention, please abide to safety attention: Safety first. Common Maintenance

13、 Attention 1. Before using, please unplug the power cord of the component system. a. Disassemble any parts the parts of circuit board and other parts. b. Cut-off and re-connecting component machine plug and other inserting parts. c. Abreast electrolysis capacitance and checking parts, Note: anti-pol

14、arity and changed wrong will cause explosion. 2. dont spray chemical dose on the component system, surroundings and any parts. 3. Except other specification of this manual, clean the appliance with a cotton swab of dedicated detergent. Notes: a. It is a kind of inflammable mixing. b.Except other spe

15、cifications of the manual, soldering point doesnt use lubricant. ES Some semi-conductor parts are easily damaged by static charges, these parts are called: ES are mainly the cores of transistor lead identification. The following technical ways can be used to reduce the damages by static charges. 1.

16、Before connecting semi-conductor or the parts. Let off the static charges of the body by connecting the earth. In the other hand, To prevent potential shock hazard, please use industrial static handle before connecting power to the checking equipment. 2. After discharging the ES parts, put it on con

17、necting appearance, for example. Aluminium surface preventing accumulating static charges to damage the parts. 3. Only use anti-static charges grounded soldering irons to discharge the parts and connecting ES parts and connecting ES parts. 4. Some soldering pads called “Anti-static charges” can also

18、 generate charges to damage ES parts. 5. Dont use poisonous and caustic agent these chemicals can generate static charges to damage the ES parts. 6. KEEP ES components in conductive packages until they are used ( mostly replacing ES components with conductive electronic-plating. metal box or similar

19、 conductive materials). 7. After taking repaired ES components from Anti-static charges cone, please Insert the ES components to the parts of circuit light now. 8. During handling sealed ES components, trying to reduce the movement of the body ( clothes rubbing and moving on the rag can generate sta

20、tic charges to damage the ES parts). Common Soldering rules 1. Use only grounded low-voltage soldering irons, and proper size and shape, these will maintain the soldering iron temperature of 230?280?. 2. USE RMA specified resin flux, include 60% Tin 40% lead. 3. To maintain soldering iron and includ

21、ing tin very well. 4. Cl ean the soldering surface, use metal brush to do it, not use poisonous and caustic agent to clean. 5. Adopt the melting ways: a.Make soldering iron head to reach normal temperature from 230?280?. b. Heat lead wire of the parts, until soldering pads melt. c.Quickly melt solde

22、ring tin by anti-static charges. Notes: Quickly operation, prevent heating the electronic-plating copper. 6. Adopt the following soldering technology. a.Make soldering iron head to reach normal temperature from 230?280?. b. Firstly hold the soldering iron and the soldering iron to the led wire of th

23、e part, until soldering pads melt. c.Quickly make soldering iron head move forwards led pins of the parts and 5 It e m s o f s a f e t y a t t e n t i o n electro-plating copper. Notes: Quickly operating, avoid heating electronic-plating copper of printed circuit board. d. Check the soldering zone s

24、trictly, use iron brush to clean more sprayed soldering tin. ICs discharging changing IC pins inserting chute some printed circuit board. Through chute to insert IC pins will be bolded and flat along electrons-plating copper when the hole is slot you can discharge and change IC. Discharging 1.Flat t

25、he discharging IC pins, point the soldering iron head to the pins, make the soldering tin melt. 2.Before discharging IC, suck off the loaded solder pads by tin with Anti static charges. Changing 1. Replaced IC is inserted in circuit board carefully. 2. Bold each IC pin point the circuit board and so

26、lder. 3. Clean soldering zone by a small hard brush ( lover protective layer) What items do you need attention on charging IC and chip? Because IC and chip are slim and damaged easily by static charges. Pay attend to the following items when changed. 1. Prevent damages for chip parts by heat. dont e

27、xposed soldering iron. 2. Pre heating soldering iron at about 100? when some parts are easily damages suddenly. 3. To prevent some parts heated hurried, soldering iron head temperature from 240?280?. 4. Because small parts cant hold too much solder tin, so use small soldering tin 0.3mm soldering. Ac

28、cording to the situation, adding soldering. 5. Be careful of charging parts, soldering speed should be quick to prevent damages for circuit board. 6. To re-connecting well, clean the basic board. 7. Prevent tin spray on the board to make printed circuit board short circuit. 8. Point the first end to

29、 make solder easily. 9. To prevent damages for parts and circuit board, please confirm damaged parts. 10.During soldering , check the soldering connecting specially for many pins small parts. 11.Checking is very important after changing use enlarger soldering leakage ,false soldering, short circuit

30、upper of printed circuit board, breaking. Not touching very well because of soldering. “Small Type” detachable transistor discharge and charging 1. Heat the round pins and clean tin of transistor . 2. Discharge heat-radiator. Screw it. 3. Discharge the heat-radiator from printed circuit board. 4. In

31、sert new transistor to the circuit board. 5. Solder each transistor pins and cut/more led wire. 6. Re- install the heat-radiator. diode discharge /charging 1. Chip the pins of led, better to chip the led, discharging the wrong led. 2. Bold two pins. Which are vertical to circuit board. 3. Check the

32、polarity of the led, then place led pins into the soldering plate. 4. Press the connecting point and solder them. 5. Check two soldering points. If not smooth, and more soldering, re-soldering. Electro-plating copper repairs When soldering time is too long , the more heat will upper electronic-plati

33、ng copper please abide to the following rules and programs. IC connecting electronic-plating copper repairs. Use led wire to solder electronic-plating copper repairing IC connecting electronic-plating copper (only for IC). 1. Use sharp knife to scrape the damaged (electronic-plating copper). 2. Stri

34、p the remind tin soldering agent from reminder. 3. Bold the skip wire to be a small “U”, soldering with IC pins. 4. Along breaking electronic-plating copper to good electronic-plating copper after soldering, cut the more skip wires. Repairing other electronic-plating copper. Using the following tech

35、nology to repair other wrong electronic-plating copper including installing 6 It e m s o f s a f e t y a t t e n t i o n skip wires on circuit board. 1. Use sharp knife to scrape wrong skip wire of electronic-plating copper at least 1/4 inchs copper to ensure once skip wire working. 2. From both sid

36、es of broken electro-plating copper soldering led wire with the nearest parts along the electronic-plating copper wire. 3. Use insulating wire soldering the near two parts (20# wire). Notes: Ensure insulating wires insulation, not happened (to parts or sharp edge). Checking progress of DVD part When

37、 the DVD is playing if music continuous unstable or without sound, that means the DVD part is out of order, and it should be checked and repaired. Notes: DVD part checking progress. Discharging laser head need to pay attention In order to prevent the laser head being destroyed by the static charges

38、that came from human body or clothes when it read the laser light led from units, the following measures should be taken when it is discharge: 1. To lay a electric blanket on the working desk and pack the exchange parts with black color packing material. 2. Put the conducting electric blanket on the

39、 conductor base, make the conducting electric blanket in a good earth connecting state. 3. Put a head on the conducting electric blanket, make it the same electric potential as the earth. 4. Then discharge the laser led and check the unit parts. 5. Complete the requirement on the conducting electric

40、 blanket. Be careful dont let clothes or other static charges resource touch the laser head parts. 6. The conducting electric ring which is on the wrist should be connected with the conducting electric blanket. 7. The conducting electric blanket and the working desk that made of copper or other cond

41、uctor should be properly connected to earth when being used. 8. When charging laser head components, printed boards and ends. 9. After finishing changed laser head components, should cut off the short circuit s ends. 7 It e m s o f s a f e t y a t t e n t i o n 8 PCB t o p p a n e l d i a g r a m 9

42、PCB b o t t o m p a n e l d i a g r a m 10 PCB t o p p a n e l d i a g r a m 11 PCB b o t t o m p a n e l d i a g r a m 1234 A B C D 4321 D C B A 3317-Jun-200515:48:18 F:My design1302dab.ddb - MCD700PCBT-003.sch SIZE:MODEL: DATE: FILE: REV: SheetofTIME: A4 drawh by:xiaojieheng Approved by: ? checked

43、 by: 123456789101112 131415161718192021222324 AM RF REG AM OSC VCC1 FM IF OUT GND1 IF BUFF ST AMIF OUT FMIF IN AMIF IN AGCDET ST/MO FM/AM L OUT R OUT MPXIN DET OUT FM OSC VCC2 RF OUT GND2 RF IN 1.2 1.2 4.5 4.5 2.2 0 4.5 4.5 4.5 1.2 1.2 0.13.7 4.5 4.5 1.2 1.2 1.2 0.1 3.7 4.4 4.4 0 0.9 IC3LA1823 X-IN

44、BO5 CE DI CL DO BO1 BO2 BO3 BO4 IO1 IF INIO2 AM IN FM IN VDD AOUT1 AIN1 PD1 PD2 AIN2 AOUT2 VSS X-OUT 123456789101112 131415161718192021222324 IC4 LC72130 1 2 34 5 6 T205B BLACK C1 47P C2 30P C4 10uF C5 3.3uF 1 2 34 5 T5118 1 2 34 5 T303B 1 2 34 5 T403B D1 SCV220 D2 SCV220 D3I384 CF1 10.7M CF3 450J C

45、F2 10.7M X1 4.5M C8 0.22uF C9 0.33uF C6 3.3uF C10 3.3uF C11 4.7uF C12 0.47uF C13 100uF C14 100uF C17 100P C22 223 C26 223 C23 223 C18 100P C27 203 C32 102 C28 103 C24 223 C33 103 C19 102 C25203 C35 222 C29 103 C363P C37 7P C38 36P C39 5P C20102 C40 36P C30 103 C41 102 C31 103 C42 501 C34 102 C43 18P

46、 C2118P C44 15P C3 47P R1 47K R7 100k R9 3.3K R10 100 R12 1K R13 1K R19 10K R14 1K R2010K R22 180 R21 10K R15 1K R2 47K R3 47K R23 2.2K R24 330 R16 1K R25 1.5K R27 220 R26 1.5K R28 220 R4 47K R11 100 R8 100K R17 1K R29 10 R5 47K R30 10 R6 47K R18 1K Q1 9014 Q2 9014 ANT1 ? L1 10uH L2 5T5L3 6T5 L4 6T5 DZ2 5V1 DZ1 5V1 C7 3.3uF 1 2 3 4 J1 CON4 1 2 3 4 5 J2 CON5 C15 100uF C16 100uF AM ANT DO CL DI CE GND 9V R OUT GND L OUT C48 203 C47 223 C45 470P