Kenwood-DMCG7R-md-sm 维修电路原理图.pdf

S: SILVER, B: BLUE Decoration plate(B07-2372-08)Knob (PLAY/PAUSE)(K27-2229-08)Knob (STOP)(K27-2231-08)Knob (REC)(K27-2227-08)Front cabinet(A02-1357-08): S(A02-1358-08): BKnob (EJECT)(K27-2232-08)Cover(F07-1624-08)Knob (EDIT MODE)(K27-2230-08)Top cover(F07-0798-08): S(F07-0799-08): BPOTABLE MD RECORDERDMC-G7RSERVICE MANUAL 1997-7/B51-5335-00 (K/K) 2740In compliance with Federal Regulations, following are reproduc-tions of labels on, or inside the product relating to laser productsafety.KENWOOD-Corp. certifies this equipment conforms to DHHSRegulations No. 21 CFR 1040. 10, Chapter 1, Subchapter J.DANGER : Laser radiation when open and interlock defeated. AVOID DIRECT EXPOSURE TO BEAM.SPECIFICATIONSSystem.MiniDisc digital audio systemRead method.Noncontact optical reading system (semiconductor laser)Rotating speed.About 400 - 900 rpmSampling frequency.44.1 kHz (32 kHz and 48 kHz are converted to 44.1 kHz and recorded)Audio compression.ATRAC (Adaptive Transform Acoustic Coding)Number of channels.Stereo : 2 ChannelsMonaural Extended mode : 1 channelRecording method.Magnetic modulation overwrite systemError correction method.AC / RC methodFrequency response.20 Hz to 20,000 Hz (3 dB)Wow & flutter .Less than unmeasurable limit (0.001 % W.PEAK)Input jack.Line/optical combined input x 1; microphone x 1(plug-in power type)Output jack .Headphone/remote control combined jackInput sensitivity : MIC H.0.25 mV/10 kMIC L.2.5 mV/10 kLINE .100 mV/20 kOutput level :phones.10 mW + 10 mW (Maximum output level/at 16)LINE .350 mV (at -12dB, standard output/50 k)Power source.DC 5 V: AC adaptor (AC 120 V, 50/60 HZ) DC 3.6 V : Lithium ion battery x 1DC 5 V: Car battery adaptor (sold separately, DC-C50)DC 4.5 V : Dry batteries case (sold separately, BC-F5)Battery life.(fully charged batteries)Dimensions (W) x (H) x (D) .109.2 mm x 29.8 mm x 81.3 mm(4-5/16 x 1-3/16 x 3-3/16)Weight (Net).Approx. 270 g (0.59 lb)Including the accessory rechargeable batteryApprox. 222g (0.49 lb)not including the accessory rechargeable battery(Continuous recording time : based on analog input and recordingmonitor volume level of 0(Continuous playback time : based on volume level of VOL 20) Time of use may vary depending on battery maker, batter type,use environment, and temperature.1. KENWOOD follows a policy of continuous advancements in development, For reason specifications may be changed without notice.2. The full performance may not be exhibited in an extremely cold location (under a water-freezing temperature).Type of batteryContinuousContinuousplayback timerecording timeRechargeable battery onlyApprox. 9.5 hoursApprox. 7 hoursAlkaline batteriesApprox. 24 hours Approx. 17 hoursRechargeable battery +Approx. 35 hours Approx. 25 hoursAlkaline batteriesNotesNotesDMC-G7R(k) COVER( 98.4.24 2:19 PM yW 2RadioFans.CN 收音机爱 好者资料库DMC-G7R2CONTENTS / ACCESSORIESAccessoriesAC adaptor(1)(W08-0668-08) : K(W08-0669-08) : M(W08-0670-08) : E(W08-0671-08) : TRechargeable battery (NB-L5) (1)(W03-5679-08)Remote control (1)(A70-1129-05) : MRemote control unit (1)(A70-1177-05) : KETCarrying case (1)(W01-0918-08)Stereo headphone(1)(W01-0920-15) : METStereo headphone(1)(W01-0941-15) : KPatch cord (1)(E30-2836-08)ContentsSPECIFICATIONS.Front coverCONTENTS / ACCESSORIES .2DISASSEMBLY FOR REPAIR.3TROUBLE SHOOTING.5PC BOARD .19SCHEMATIC DIAGRAM .23EXPLODED VIEW .27PARTS LIST.29DMC-G7R(k) COVER( 98.4.24 2:19 PM yW 3RadioFans.CN 收音机爱 好者资料库Caution on DisassemblyFollow the below-mentioned notes when disassemblingthe unit and reassembling it, to keep it safe and ensureexcellent performance:1. Take the battery and minidisc out of the unit.2. When disassembling the machine, be sure to withdrawthe power plug from the socket in advance.3. When disassemble the parts, remove the nylon band orwire holder as necessary. To assemble after repair, be sure to arrange the wires asthey were. If a screw of different length is fitted to the MD mecha-nism (the screw of the part to be fitted to the MDmechanism chassis), it may contact the optical pickup,resulting in malfunction.4. When repairing, pay due attention to electrostatic chargesof IC.1Bottom Cover1. Screw . (A1) x57-12Disc Cover1. Screw . (B1) x47-1(Note)2. Flexible PWB . (B2) x13Main PWB1. Screw . (C1) x37-22. Flexible PWB . (C2) x43. Soldering . (C3) x24Front Cabinet1. Screw . (D1) x17-22. Remove the front cabinet in the arrow direction.REMOVALPROCEDURESTEPFIGUREBottom Cover(B1) x22x2mm(B1) x22x2mm(A1) x22x2mm(A1) x22x2mm(A1) x12x2mm(B2) x1Disc CoverFigu re 7-1Figure 7-2Eject knob leverEject leverLid opening and closing springLid opening and closing springLid opening and closing leverEngage the springat the upper side.Lid opening and closing leverFigure Figure 7-3Figure 7-4Note:When removing the upper lid, at first turn the operation knobside in the arrow direction to remove.Installing the front cabinet (See Fig. 7-3.)1. Make sure that the lid opening and closing spring has beenengaged at the upper side as shown in Figure .2. Fit the MD lid right pin into the lid opening and closing leverto install it.Note: Take care since the antivibration rubber may come off. If the main PWB has been installed previously, fit the knob tothe HOLD switch shown in Figure . If the mechanism has been installed, the antivibration rubbermay come off from the center cabinet fitting part when thefront part of center cabinet is widened.(C1) x32x2.5mm(D1) x12x2.5mm(C3) x1(C2) x2(C3) x1Main PWBFront Cabinet(C2) x2Front CabinetLid opening and closing leverCenter CabinetAntivibration rubberHOLD knobMD lidMD lid right pinSWDMC-G7R3DISASSEMBLY FOR REPAIRDMC-G7R(k) COVER( 98.4.24 2:19 PM yW 6DMC-G7R4DISASSEMBLY FOR REPAIRRemove the mechanism according to the disassembling meth-ods 1 to 4. (See Page 7.)How to remove the disc motor (See Fig. 8-1.)1. Remove the solder joint (A1) x 1 of flex PWB.2. Remove the screws (A2) x 3 pcs. and remove the discmotor. Take care so that the turnrable is not damaged.Figure 8-4(A2) x 31.4 x 4.5mmFlexible PWBsolder joint(A1) x1Disc MotorMotor SpacerMechanism PWBMechanismFigure 8-1(B2) x21.4x2.2mm(B1) x2Remove the solder joint.Slide MotorFigure 8-2Figure 8-3Shaft (C2) x 1(C1) x 21.4 x 3mm(C1) x 11.4 x 2.5mm(C1) x 12 x4.5mmPickup UnitMagnetic field arm blockMagnetic headHead intervening flexible PWB(D1) x11.4x2mmUnsolder(D2) x2How to remove the slide motor (See Fig. 8-2.)1. Remove the solder joint (B1) x 1 of slide motor lead wire.2. Remove the screw (B2) x 1, and remove the slide motor.Note:Take care so that the motor gear is not damaged.(If the gear is damaged, noise is raised in search mode.)How to reinstall the optical pickup unit(See Fig. 8-3.)1. Remove the screws (C1) x 5 pcs.2. Remove the magnetic fielt arm block from the pickup, andmove the magnetic field arm block outwards.Note:Take due care so that the magnetic head is not damaged.3. Withdraw a little the slide motor side shaft (C2) x 1 pcs., andslowly raise the optical pickup.How to remove the magnetic head(See Fig. 8-4.)1. Remove the screw (D1) x 1 pc.2. Remove the unsolder (D2) x 2 pcs. which connects themagnetic head and the head hookup flex.Note:Mount carefully so as not to damage the magnetic head.DMC-G7R(k) COVER( 98.4.24 2:19 PM yW 7DMC-G7R5TROUBLE SHOOTING Abnormal displayNoYesIs waveform output from IC 401 pins 13 to 15?Check for pattern breakage of flexible PWB, check fordefects of display microcomputer (replace the display unit).Is waveform output from CNS 402 pins 1 to 3?Are the pin7 (VCC) and pin 6 (GND) normal? Playback state cannot be setIs playback state unsettable for high reflection disc and lowreflection disc?YesCheck between IC401 andCNS402.NoCheck the periphery of IC401.Proceed to Test mode check.YesOnly the low reflection disc cannot be played back.Only the high reflection disc cannot be played back.YesIs the pin 46 of IC401 in L state when the high reflection discis inserted?Is the pin 51 of IC401 and pin 23 of IC101 in L state?Check SW902, mechanism flexible PWB and CN601.NoProceed to Test mode check.YesNoYesIs the pin 46 of IC401 in L state when the high reflection discis inserted?Is the pin 51 of IC401 and pin 23 of IC101 in L state?NoProceed to Test mode check.YesCheck SW902, mechanism flexible PWB and CN601.It is advisable to use the TEST mode (refer to Error Data Display Mode, P15) indicating the causes of troubles beforestarting repair. Causes of operation errors (up to 10 errors) are recorded as error codes. This information is usefulfor repair.When does not functionWhen the CD section does not operate When the objective lens of the optical pickup is dirty,this section may not operate.Cleanthe objective lens,and check the playback operation.When this section does not operate even after the above step is taken,checkthe following items.Remove the cabinet and follow the troubleshooting instructions.Track skipping and/or no TOC(Table Of Contents) may be caused by build up of dust other foreign matter on the laser pickup lens.Before attempting any adjustment make certain that the lens is clean. If not, clean it as mentioned below.Turn the power off.Gently clean the lens with a lens cleaning tissue and a small amount of isopropyl alcohol.Do not touch the lens with the bare hand.Is the power supply turned on when the remote controlbutton or main unit button is pressed?NoPerform the check stated in item Power is not turned onwhen the PLAY button is pressed.Perform the check stated in item Abnormal display.NoYesDoes the display operate normally?Is playback state set?YesPerform the check stated in item Playback state connot beset.NoIs audio output normal?YesPerform the check stated in item Audio playback circuit.NoIs recording/playback operation normal?YesPerform the check stated in item Recording/playbackoperation.No Power is not turned on when the / buttonis pressed.NoNoYesCheck the periphery of remote controller and main unitheadphone terminal (J703) and IC401.NoIs the pin 26 of IC401 in H state?Is operation normal when the main body button is pressed?Check the position of Hold switch.Is power turned on when the remote control button ispressed?NoAre IC401 pin 50 set to L?Check the DISC IN (SW904) switch of mechanism PWB.YesYesIs clock supplied to the pins 83 and 86 of IC401?NoCheck that voltage is applied to the periphery of IC403.YesIs 2.5V applied to TP201?NoCheck whether there is solder touch of part connected tothe +2.5V line.DMC-G7R(k) COVER( 98.4.24 2:19 PM yW 10DMC-G7R6TROUBLE SHOOTINGContinued from the preceding pageIn case of high reflection disc, proceed to the item normalplayback.In case of low reflection disc, check whetheradjustment is within allowable range in the TOTAL leveladjustment step.Check whether values of pins 10, 11, 14, and 15 of IC201 andpins 30 and 32 of IC101 (TP143) change when the /button is pressed.NoDoesnt the disc motor run at high speed in the same step?Check ADIP waveform of pin 4 of IC201.NoYesIs tracking gain adjustment within allowable range in thesame step?Check whether values of pins 16 to 19 of IC201 and TP144(TEOUT) change when the / button is pressed.NoYesIs adjustment within allowable range in tracking errorbalance adjustment step?Check whether value of pin 20 of IC201 and TP144(TEOUT)changes or DC shift occurs when the / button ispressed.NoYesIs tracking servo applied in focus gain fine adjustment step?Check waveforms of pins 54 and 55 of IC201, pins 18, 19, 21,and 23 of IC601, pins 4 and 6 of CNS101.NoYesIs slide servo applied in continuous playback step?Replace IC201.NoYesYesCheck item Normal Playback. Test mode checkInsert a high reflection (low reflection) disc, and once perform automatic adjustment in AUTO mode, and then check in MANUAL mode.Simultaneously observe waveforms of EFM(TP145), FEOUT(TP143), and TEOUT(TP144).Does the optical pickup move to outer/inner periphery whenthe / button is pressed?Check the pins 56 and 57 of IC201, the pins 25, 27, 29 and 30of IC601, the pins 10 and 11 of CNS601, and the slide motorterminal.NoIs tracking error offset measurement within allowable range?YesCheck Vref values of pins 3 and 4 of IC101 and pin 22 of IC201.NoIs focus error offset measurement within allowable range?YesCheck Vref values of pins 3 and 4 of IC101 and pin 22 of IC201.NoYesIs laser power normal when laser lights?Check the pins 21 and 22 of IC101, the pins 6 and 52 of IC401,the periphery of Q101, Q102, and Q103, CNS101, and pickupflexible PWB insertion.NoYesDoes focus access occur in focus gain rough adjustmentstep?Check the pins 52 and 53 of IC201, the pins 10, 12, 14, and 15of IC601,and the pins 5 and 7 of CNS101.NoYesIs adjustment out of allowable range?Check whether values of pins 10, 11, 14, and 15 of IC201, pins30 and 32 of (IC101) (TP143) change when the / buttonis pressed.NoDoes the disc motor rotate in the same step?Check as stated in item The disc motor does not rotate.NoIs focus servo applied in tracking gain adjustment step?Check timing of pins 91 and 92 of IC401 and TP144(TEOUT).NoYesYesDoesnt the disc motor rotate at high speed in the same step?NoCheck EFM waveform of pin 23 of IC201 in case of highreflection.Check ADIP waveform of pin 4 of IC201 in case of low reflection.YesIs tracking gain adjustment within allowable range in thesame step?Check whether values of pins 16 to 19 of IC201 andTP144(TEOUT) change when the / button is pressed.NoYesIs adjustment within allowable range in tracking errorbalance adjustment step?Check whether value of pin 20 of IC201 and TP144(TEOUT)changes or DC shift occurs when the / button ispressed.NoYesIs tracking servo applied in focus gain fine adjustment step?Check waveforms of pins 54 and 55 of IC201, pins 18, 19, 21,and 23 of IC601, pins 4 and 6 of CNS101.NoYesIs slide servo applied in continuous playback step?Replace IC201.NoYesIs cluster address counted up continuously in the same step?Check waveforms of pins 53 to 56 of IC101 and pins 23 to 25 ofIC201. (In case of low reflection check also the waveform of pin4 of IC201.)NoYesYesContinued on the next page.DMC-G7R(k) COVER( 98.4.24 2:19 PM yW 117DMC-G7RTROUBLE SHOOTING Recording/playback operationInsert a low reflection disc, and ascertain audio output by normal playback, and then set TEST REC mode.YesDoes the head move down, failing to start record evenwhen the continuous record mode is set after address?Check voltage of pins 56 and 57 of IC401, pins 2, 4, 7, and 9 ofIC851, pins 12 and 13 of CNS601. Check whether disc isrecord-inhibited.NoIs RF waveform output TP145 in recording/playback mode?Does level of pins 6 and 54 of IC401 and pin 22 of IC101change depending on record and playback?Is RF pattern output from IC201 pin 60 and CNS201 pin 2?YesNoCheck for soldering failure of IC201 and CNS201.NoCheck periphery of IC401 and IC101.Check whether there is any damage in IC101, periphery ofQ101, and laser diode.YesCheck for defects of IC351 in head drive flexible PWB,Q351 to 354, head, flexible PWB.NoYesYesIs audio monitor output given in normal mode LINE INrecord?Check waveforms of pins 111, 12, 14, 15 of IC501, pin