Jvc-XMPX-70-WT-Service-Manual电路原理图.pdf

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1、SERVICE MANUALPORTABLE MINIDISC PLAYERNo.20897Jan. 2001COPYRIGHT 2001 VICTOR COMPANY OF JAPAN, LTD.XM-PX70WT/BU/PNXM-PX70WT/BU/PNArea Suffix UB Hong KongContentsSafety PrecautionsAttention whenMD pick up is exchangedDisassembly methodAdjustment methodMaintenance of laser pickupReplacement of laser p

2、ickupDescription of major ICsAttention when partsare exchanged1-21-31-41-91-101-101-111-24XM-PX70WT/BU/PN1-21. This design of this product contains special hardware and many circuits and components specially for safety purposes. For continued protection, no changes should be made to the original des

3、ign unless authorized in writing by the manufacturer. Replacement parts must be identical to those used in the original circuits. Services should be performed by qualified personnel only.2. Alterations of the design or circuitry of the product should not be made. Any design alterations of the produc

4、t should not be made. Any design alterations or additions will void the manufacturers warranty and will further relieve the manufacture of responsibility for personal injury or property damage resulting therefrom.3. Many electrical and mechanical parts in the products have special safety-related cha

5、racteristics. These characteristics are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in

6、 the Parts List of Service Manual. Electrical components having such features are identified by shading on the schematics and by ( ) on the Parts List in the Service Manual. The use of a substitute replacement which does not have the same safety characteristics as the recommended replacement parts s

7、hown in the Parts List of Service Manual may create shock, fire, or other hazards.4. The leads in the products are routed and dressed with ties, clamps, tubings, barriers and the like to be separated from live parts, high temperature parts, moving parts and/or sharp edges for the prevention of elect

8、ric shock and fire hazard. When service is required, the original lead routing and dress should be observed, and it should be confirmed that they have been returned to normal, after re-assembling.5. Leakage currnet check (Electrical shock hazard testing)After re-assembling the product, always perfor

9、m an isolation check on the exposed metal parts of the product (antenna terminals, knobs, metal cabinet, screw heads, headphone jack, control shafts, etc.) to be sure the product is safe to operate without danger of electrical shock.Do not use a line isolation transformer during this check.Plug the

10、AC line cord directly into the AC outlet. Using a “Leakage Current Tester“, measure the leakage current from each exposed metal parts of the cabinet , particularly any exposed metal part having a return path to the chassis, to a known good earth ground. Any leakage current must not exceed 0.5mA AC (

11、r.m.s.)Alternate check methodPlug the AC line cord directly into the AC outlet. Use an AC voltmeter having, 1,000 ohms per volt or more sensitivity in the following manner. Connect a 1,500 10W resistor paralleled by a 0.15 F AC-type capacitor between an exposed metal part and a known good earth grou

12、nd.Measure the AC voltage across the resistor with the AC voltmeter. Move the resistor connection to eachexposed metal part, particularly any exposed metal part having a return path to the chassis, and meausre the AC voltage across the resistor. Now, reverse the plug in the AC outlet and repeat each

13、 measurement. voltage measured Any must not exceed 0.75 V AC (r.m.s.). This corresponds to 0.5 mA AC (r.m.s.). 1. This equipment has been designed and manufactured to meet international safety standards.2. It is the legal responsibility of the repairer to ensure that these safety standards are maint

14、ained.3. Repairs must be made in accordance with the relevant safety standards.4. It is essential that safety critical components are replaced by approved parts.5. If mains voltage selector is provided, check setting for local voltage.Good earth groundPlace this probe on each exposedmetal part.AC VO

15、LTMETER(Having 1000 ohms/volts,or more sensitivity)1500 10W0.15 F AC TYPE!Burrs formed during molding may be left over on some parts of the chassis. Therefore, pay attention to such burrs in the case of preforming repair of this system.XM-PX70WT/BU/PN1-3The laser diode in the traverse unit (optical

16、pick up) is easy to be destroyed by clothes and the human body to the electrified static electricity.Please note the explosion by static electricity when repairing.In the equipment which uses an optical pick up (laser diode), an optical pick up is destroyed by the static electricity of the work envi

17、ronment. Please do the earth processing and work.2. About the earth processing for the electrostatic destruction prevention1) Earth of work standPlease pull the conductive material (conductive sheet) or the iron plate to the depository place of the traverse unit (optical pick up), and take the earth

18、 to ground.2) Human body earthPlease use the anti-static wrist strap to exhaust the electrified static electricity to the human body.3. Handling the optical pick up1) Please return according to a correct procedure based on short processing after exchangingparts. 2) Do not use a tester to check the c

19、ondition of the laser diode in the optical pick up .The tester s internalpower source can easily destroy the laser diode. 4. Attention when unit is disassembledPlease refer to “Disassembling method“ for how to detach .Conductive material (conductive sheet) or the iron plateanti-static wrist strapAtt

20、ention when MD pickup is exchanged1. About the static electricity protection measuresSolder short1) Please be sure to solder before a flexible wire is removed from connector on a main printed circuit board as shown. if you removes without soldering.the MD picking up assembly might destroy2) When ins

21、talling , solder in the part of short round should be removed after a flexible wire is connected with connector.XM-PX70WT/BU/PN1-4Shift the door lever to open the door.Remove the four screws A and detach the MD door assembly from the main body.1.2.Disassembly methodRemoving the MD door assembly (See

22、 Fig.1 and 2)Prior to performing the following procedure, remove the MD door assembly.Turn the holder assembly as shown in Fig.3.Pull the side arm (L) marked a and remove outward. Open the holder assembly as shown in Fig.4. Move the marked b in the direction of the arrow and release it from the shaf

23、t.Move the part c inward and pull out the holder assembly from the shaft.1.2.3.4.Removing the holder assembly (See Fig.3 and 4)When reassembling, first reattach the part c to the shaft of the chassis assembly. And next, fit the “U-shaped” notch to the shaft.ATTENTION: MD door assemblyMD door assembl

24、yDoor leverDoor leverAAFig.1Fig.2Fig.3Fig.4Holder assemblyPart aPart b“U-shaped” notchPart c shaftSide arm (L)Holder assemblyHolder assemblyHolder assemblyPart cXM-PX70WT/BU/PN1-5Prior to performing the following procedure, remove the MD door assembly and the holder assembly.Open the battery lid. Re

25、lease the tab d and pull out the battery lid.Remove the screw B and pull out the side arm (R) upward.Remove the two screws C and pull out the eject unit.Remove the screw D, E, F, G and H attaching the chassis assembly respectively.Disengage the three joints e of the bottom case and the battery holde

26、r. Remove the chassis assembly and the jack cover at once.1.2.3.4.5.Removing the chassis assembly (See Fig.5 to 7)Fig.5Fig.6Fig.7Chassis assemblySide arm (R)Battery lidTab dJoint eJoint eDBBattery lidChassis assemblyCEject unitCChassis assemblyJoint eJoint eHEGFBottom caseBattery holderXM-PX70WT/BU/

27、PN1-6Solder the short circuit round of the flexible wire on the main board.Disconnect the flexible wires from connector CN301 and CN401 on the main board.Remove the one screw I attaching the main board. Remove the main board with the battery holder .Unsolder the four soldered parts f retaining the m

28、ain board and the battery holder.1.2.3.4.Removing the main board and the battery holder (See Fig.8 and 9)Prior to performing the following procedures, remove the MD door assembly, the holder assembly and the chassis assembly.Prior to performing the following procedures, remove the MD door assembly,

29、the holder assembly, chassis assembly and the main board.Disconnect the flexible wire extending from the headphone jack from connector CN601 on the main board.1.When reassembling, connect the flexible wire extending from the pickup to the connector on the main board and unsolder the short circuit ro

30、und.ATTENTION: Before disconnecting the flexible wire extending from the pickup, make sure to solder the short circuit round to prevent damage to the pickup.ATTENTION: Removing the headphone jack assembly (See Fig.10)Fig.8Fig.9Fig.10Soldering fSoldering fBattery holderICN401CN301Short circuit roundH

31、eadphone jack assemblyMain boardShort circuit roundCN401CN301Battery holderHeadphone jack assembly Main boardCN601XM-PX70WT/BU/PN1-7Unsolder the part g on the flexible wire extending from the underside of the chassis assembly to the spindle motor.1.Remove the three screws J attaching the spindle mot

32、or.2.Removing the spindle motor (See Fig.11)Remove the slit washer and the worm gear from the underside of the chassis assembly.Remove the screw K attaching the shaft holder and draw out the shaft (lead screw).Pull out the pickup unit and the lead screw while disengaging the part h and i.1.2.3.Remov

33、ing the pickup unit (See Fig.11)Prior to performing the following procedures, remove the MD door assembly, the holder assembly, the chassis assembly and the main board.Do not spill flux on the gear and others.ATTENTION: When handling the pickup unit, touch the parts marked in Fig.13 only.ATTENTION:

34、Remove the screw L and the lead spring.Pull out the shaft from the pickup.1.2.Removing the pickup (See Fig.12 and 13)When handling the pickup unit, touch the parts marked in Fig.13 only.ATTENTION: Worm gearSlit washerKJShaft holderSpindle motorPart gPickup unitPart hLead screwPart iFig.11Chassis ass

35、emblyFig.12Fig.13Lead screwLLead springPickupTouch these parts only.XM-PX70WT/BU/PN1-8Peel off the adhesive tape j on the flexible wire on the underside of the feed motor.Unsolder soldering k connecting the flexible wire to the feed motor.Remove the two screws M attaching the feed motor.1.2.3.Removi

36、ng the feed motor (See Fig.14)When reassembling, reattach the flexible wire with an adhesive tape andsolder.ATTENTION: Chassis assemblyFeed motorjSoldering kMFig.14Pickup unitMXM-PX70WT/BU/PN1-9Adjustment methodThis model is auto adjustment by Remote Controller.Please adjust the attached remote cont

37、roller.LCD indication5. M o T GTest mode setting OK. Indicate at 2sec.When LCD indicate NG at another item,Return back this item by press (STOP) keyResume initializeLCD Indication change :* Initializing*ResumeInitializingServoServo initializeLCD Indication change : FEEDExecutes by LCD Indication cha

38、nge :FwdBwd:Pickup is go to outsidePress LCD Indication change :OK :Pickup is go to insideMO TG Insert the Recordable disc. Executes by LCD Indication change : MO DISC ADJUSTExecutes by LCD Indication change : Press LCD Indication change : OK*MO DISC ADJUSTPre TG Insert the Pre master disc.Executes

39、by LCD Indication change : Pre DISC ADJUSTExecutes by LCD Indication change : XXYYZZ Press RESETExecutes by LCD Indication : Left out the test mode ,power off ,and END.Press and key together more than 3sec. at power off condition.next item .before item.PLAY LASER Insert the laser power meter. Execut

40、es by LCD Indication change :XX:YYUp by .Down by LCD Indication change :VW.YYSetting by LCD Indication change : OK PLAY LASER7.*Adjusting*Adjusting*Adjusting*AdjustingFEED*0. TMD-V2Adjust power-supply voltage 1.5v 20mv before the laser power is adjusted and stops. Laser power adjust 560 adjustEquipm

41、ents- 1. Remote controller 2. DC power supply3. Laser power meter 4. MO disc (AU-1) 5. Pre master disc (TGYS 1)XM-PX70WT/BU/PN1-10Turn off the power switch and,disconnect thepower cord from the ac outlet.Replace the pickup with a normal one.(Refer to “Pickup Removal“ on the previous page)Plug the po

42、wer cord in,and turn the power on.At this time,check that the laser emits for about 3seconds and the objective lens moves up and down.Note: Do not observe the laser beam directly.Play a disc.Check the eye-pattern at TP1.Finish.Maintenance of laser pickup(1) Cleaning the pick up lensBefore you replac

43、e the pick up, please try to clean the lens with a alcohol soaked cotton swab. (2) Life of the laser diode When the life of the laser diode has expired,the following symptoms will appear.1. The level of RF output (EFM output:ampli tude of eye pattern) will below.Is the level ofRFOUT under0.35Vp-p?Re

44、place it.NOYESO.K(3) Semi-fixed resistor on the APC PC board The semi-fixed resistor on the APC printed circuit board which isattached to the pickup is used to adjust the laser power.Since this adjustment should be performed to match the characteristics of the whole optical block, do not touch the s

45、emi-fixed resistor.If the laser power is lower than the specified value,the laser diode is almost worn out, and the laser pickup shouldbe replaced.If the semi-fixed resistor is adjusted while the pickup is functioning normally,the laser pickup may be damageddue to excessive current.Replacement of laser pickup