JVC MX-K50 Service Manual

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Instruction manual (32 pages)

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Instructions manual (64 pages)

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Page 1: Table Of Contents
MX-K50 SERVICE MANUAL COMPACT COMPONENT SYSTEM MX-K50 Area suffix UW --- Brazil,Mexico,Peru U --------------- Other Areas DISC CHANGE STAND BY STANDBY/ON CD-R/RW P LAYBACK MX -K50 SOUND M ODE CLOCK STANDBY/ ON /TIMER DISPLAY ACTIVE BASS SLEEP EX. LEVEL ACTIVE BASS EXT ENSION...
Page 2 MX-K50 1. 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 design 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.
Page 3: Preventing Static Electricity
MX-K50 Preventing static electricity 1. Grounding to prevent damage by static electricity Electrostatic discharge (ESD), which occurs when static electricity stored in the body, fabric, etc. is discharged, can destroy the laser diode in the traverse unit (optical pickup). Take care to prevent this when performing repairs.
Page 4: Important For Laser Products
MX-K50 Important for laser products 5.CAUTION : If safety switches malfunction, the laser is able 1.CLASS 1 LASER PRODUCT to function. 2.DANGER : Invisible laser radiation when open and inter 6.CAUTION : Use of controls, adjustments or performance of lock failed or defeated. Avoid direct exposure to beam.
Page 5: Disassembly Method
MX-K50 Metal cover Disassembly method Removing the metal cover (See Fig.1) Remove the three screws A attaching the metal cover on the back of the body. Remove the six screws B attaching the metal cover on both sides of the body.
Page 6 MX-K50 CW105 CD board Rear panel CD changer unit RCW6 Fig.6 Front panel assembly CD changer unit Main board Fig.5 (both sides) Rear panel Fig.7 Removing the front panel assembly FCW3 Front panel Main board JCW2 (See Fig.8 to 10)
Page 7 MX-K50 Joint2 (Bottom side) Removing the heat sink & amp. board (See Fig.8, 11 and 12) Prior to performing the following procedure, remove the metal cover and CD changer unit. Fig.10 Disconnect the card wire from the connector ACW1 Rear panel and the harness from the connector ACW2 on the amp.
Page 8 MX-K50 Removing the main board (See Fig. 14) FCW3 JCW2 Prior to performing the following procedure, remove JCW1 ECW1 the metal cover, CD changer unit and rear panel. Main board HCW3 Voice board Disconnect the card wire from the connector FCW3...
Page 9 MX-K50 Front panel assembly (inner side) <Front panel assembly> CD switch board Prior to performing the following procedure, remove the front panel assembly. UCW1 Removing the CD switch board (See Fig.1) Disconnect the card wire from the connector UCW1 on the CD switch board.
Page 10 MX-K50 CD changer uint (reverse side) <CD changer unit> Prior to performing the following procedure, remove CD tray the CD changer unit. Removing the CD tray (See Fig.1 and 2) CD board Loading pulley Turn the black loading pulley gear on the under side...
Page 11 MX-K50 Removing the sensor board (See Fig.5) CD tray (reverse side) Prior to performing the following procedure, remove the CD tray. Remove the screw A attaching the sensor board on the CD tray. Remove the sensor board releasing the two tabs a.
Page 12 MX-K50 Removing the belt, the CD board and the switch board (See Fig.8 and 9) Belt Prior to performing the following procedure, remove the CD tray. Detach the belt from the pulley on the upper side of the CD changer unit (Do not stain the belt with grease).
Page 13 MX-K50 Removing the CD mechanism holder assembly (mechanism included) Motor connecter (See Fig.10 to 13) Disconnect the harness from connector on the CD mechanism board in the CD mechanism assembly on the under side of the CD changer unit. Disconnect the card wire from the pickup unit connector.
Page 14 MX-K50 <CD mechanism section> Shutter Shaft Pickup unit Removing the CD mechanism holder from the CD • chager unit. (Refer to "Removing the CD mechanism holder assembly" ) Removing the pickup unit See Fig.1) 1. Removing the cut washer on the feed gear sleeve and pull out the feed gear.
Page 15: Cassette Mechanism Section
MX-K50 R/P Head <Cassette mechanism section> Removing the record/playback mechanism. Removing the R/P head. 1. Remove the screw A on the right side of the R/P head.(Fig.1, Fig.2) 2. Remove the screw B on the left side of the R/P head.(Fig.1, Fig.2) Remove the erase head.
Page 16 MX-K50 Motor Mecha. terminal board Removing the motor. 1. Remove the two screws D fixing the motor. Be careful to grease's splash when the drive belt comes off.(Fig.5, Fig.6) 2. Unsolder the motor terminal.(Fig.5) Removing the mechanism board. Unsolder the four parts a on the solenoid...
Page 17 MX-K50 < Speaker section > It is exchange in a unit. Please do not decompose as much as possible. Removing the front panel (See Fig. 1 and 2) The tool with Remove the four bosses and duct, and remove the a flat tip front panel.
Page 18: Wiring Connection
MX-K50 Wiring connection Color codes are shown below. Brown Orange Yellow Green Blue Violet Gray White Black CW302 CW301 1-18...
Page 19: Adjustment Method
MX-K50 Adjustment method 1. Tuner * Adjustment Location of Tuner PCB ITEAM AM(MW) OSC Adjustment AM(MW) RF Adjustment 9kHz step : 531~1602kHz 594 KHz Received FREQ. 10kHz step : 530~1710kHz 600 KHz Adjustment point Output 1~7.0V 0.5V Maximum Output(Fig.1) MAIN TESTER Fig.1 OSC Voltage...
Page 20: Mx-K50
MX-K50 FM THD Adjustment SSG FREQ. 98 MHz Adjustment Output Antenna point FM DETECTOR COIL Terminal (FM DET) Oscilloscope FM S.S.G Input 60 dB Output Speaker Minumum Distortion (0.4% below) Terminal Input output (Fig.2) Distortion Meter Fig.2 IF CENTER and THD Adjustment FM Search Level Adjustment SSG FREQ.
Page 21 MX-K50 2. Cassette Deck To adjust tape speed Notes Cassette Deck Frequency Counter 1) Measuring tape: i) VT-712/MTT-111(or equivalent) (Tapes recorded with 3kHz) SPK OUT ii) AC-225/MTT-5512(or equivalent) output Fig.1 2) Connect the cassette deck to the frequency counter as in fig.1.
Page 22 MX-K50 2. Adjust Deck 2 Play Level/REC BIAS Pre-Setup Step Item Pre-Setup To Adjust Standard Remark Condition After putting VT-703 AZIMUTH SPK OUT Turn the control Max output After into Deck 2 (VTVM is screw to as and same phase...
Page 23: Flow Of Functional Operation Until Toc Read
MX-K50 Flow of functional operation until TOC read Check Point Play Key Power ON RESET a CD LSI Confirm that the voltage at the pin17 of KB9226(IC101) is "L" "H". Confirm that the voltage at the pin33 LIMIT SW ON of KB9226(IC101) is "H"...
Page 24: Maintenance Of Laser Pickup
MX-K50 Maintenance of laser pickup (1) Cleaning the pick up lens (2) Life of the laser diode Before you replace the pick up, please try to When the life of the laser diode has expired, clean the lens with a alcohol soaked cotton the following symptoms will appear.
Page 25: Troubleshooting
MX-K50 Troubleshooting 1. Amplifier Power malfunction No output ,5,6,7 5,6,7 1-25...
Page 26 MX-K50 2.Tuner malfunction (FM/AM) 3.Tape HA12235F 3,4,27,28 HA12235F JIC1(HA12235F) PIN5,26 JC63L,JC63R,JR65L,JR65R 1-26...
Page 27 MX-K50 4.CD 1-27...
Page 28: Description Of Major Ics
MX-K50 Description of major ICs 5L9290 (IC201) : Digital signal processor for CDP 1. Pin layout VSSA_PLL BCKO VCO1LF LRCKO VSSD_PLL SADTO VDDD_PLL DATX VDDD1_5V C2PO S5L9290X JITB DSP+DAC XOUT SBCK 48-LQFP-0707 VSSD1_5V VDDD3-5V EFMI VSSD2-3V LOCK VDDD2-3V SMEF MUTE...
Page 29 MX-K50 3. Pin function Symbol Function VSSA_PLL Analog Ground for DPLL VCO1LF Pump out for VCO1 VSSD_PLL Digital Ground Separated Bulk Bias for DPLL VDDD_PLL Digital Power Separated Bulk Bias for DPLL (3V Power) VDDD1-5V Digital Power (5V Power, I/O PAD) X'tal oscillator input (16.9344MHz)
Page 30 MX-K50 KB9226 (IC101) : RF amp. & servo signal processor 1. Pin layout PDAC PDBD LOCK WDCK S1L9226X CLVI RESET DCCI DCCO MDATA VREF ISTAT 2. Block diagram Center Tracking Error RF & Focus RF AGC & EQ Voltage (RW)
Page 31 MX-K50 3. Pin function Pin No. Symbol Function RF summing amp. inverting input RF summing amp. output RFO DC eliminating input(use by MIRROR, FOK ,AGC & EQ terminal) RF equalizer output EFMI EFM slice input. (input impedance 47K) Main power supply...
Page 32 MX-K50 LC72131(IC02) : PLL frequency synthesizer for electron alignment 1. Pin layout 2. Block diagram XOUT Phase Reference Detector Driver AOUT Charge Pump Swallow Counter FMIN 1/16,1/17 4bits Unlock AMIN Detector IFIN 12bits Programmable Divider Universal Data Shift Register & Latch...
Page 33 MX-K50 3.Pin function (2/2) Symbol Pin No. Type Functions Circut confguration Used as the synchronization clock when serial data is input Clock to the LC72131 (DI ), or when serial data is output (DO). Inputs serial data sent from the controller to the LC72131M.
Page 34: Block Diagram
MX-K50 LC86P6548 (UIC1) : Microcontroller 1.Pin layout S48/PG0 S19/PC3 S18/PC2 S49/PG1 S17/PC1 S50/PG2 S51/PG3 S16/PC0 VDD3 S15/T15 S14/T14 S13/T13 S12/T12 VSS2 S11/T11 VDD2 S10/T10 S9/T9 S8/T8 S7/T7 P10/SO0 S6/T6 S5/T5 P11/SI0/SB0 S4/T4 P12/SCK0 S3/T3 P13/SO1 P14/SI1/SB1 S2/T2 S1/T1 P15/SCK1 2.Block diagram...
Page 35 MX-K50 3. Pin function Pin No. Symbol Function P16/BUZ Buzzer output P17/PWM0 Timer 1 output (PWM0 output) 8bit input/output port Input/output in bit unit 15V withstand at N-channel open drain output P70/INT0 INT0 input /HOLD release/N-channel Tr. ouptput forwatchdog timer...
Page 36 MX-K50 HA12237 (JIC1) : Audio signal processor 1. Block diagram REC OUT(L) REC OUT(R) ALC(L) ALC(R) REC IN(L) REC IN(R) PB OUT(L) PB OUT(R) TAI(L) TAI(R) EQOUT(L) EQOUT(R) PB-EQ(L) PB-EQ(R) PB-NF2(L) PB-NF2(R) 2. Pin function Pin No. Symbol Function Pin No.
Page 37 MX-K50 M66010 (UIC2) : I/O control 1.Pin layout 2.Block diagram Shift register 1 SERIAL DATA OUTPUT D24 D23 D22 D3 D2 D1 CLOCK INPUT SET INPUT CHIP SELECT Q24 Q23 Q22 Q3 Q2 Q1 PARALLEL INPUT Parallel output latch DATA I/O...
Page 38 MX-K50 TDA7442D (FIC1) : Audio processor 1.Pin layout R_IN3 R_IN4 R_IN2 LOUT R_IN1 ROUT L_IN1 AGND L_IN2 L_IN3 CREF L_IN4 MUXOUTL IN(L) DIG-GND MUXOUT(R) TREBLE(R) IN(R) TREBLE(L) BIN(R) BOUT(R) BIN(L) BOUT(L) 2.Block diagram 5.6K 5.6nF 100nF 100nF 100nF 2.2 F...
Page 39 MX-K50 L4959 (RIC1) : Voltage regulator 1.Pin layout OUT 12V(a) OUT 8.6V EN 8.6V EN 12V(a) EN 12V(b) N.C. OUT 5.6V OUT 12V(b) TAB CONNECTED TO PIN 6 D97AU716A 2.Block diagram 2/10 5.6V, 250mA OUT 5.6V REGULATOR 8.6V, 600mA OUT 8.6V...
Page 40 MX-K50 KA9258D (IC301 ) : 4-ch Motor driver (on the CD board) 1.Block diagram 28 27 26 25 24 23 22 21 20 19 18 17 16 15 REGULATOR T • S • D MUTE 10 11 12 13 14 LA1837 (IC01) : FM IF/DET AM RF/IF/DET 1.Block diagram...
Page 41 MX-K50 M65855FP (EIC1) : Sound processor 2. Pin function 1. Pin layout Pin No. Symbol Function CLOCK Echo level control with external DC voltage ECHOVOL ECHOVOL ECHOMUTE To connect 1/2 Vcc output and filter capacitor V CC OP2 IN Uses external C to from an D/A conversion...
Page 42 MX-K50 BA3837 (IC301 ) : MIC mixer (on the voice board) 1.Block diagram ROUT LOGIC LOUT BIAS 2.Pin function Symbol Function Pin No. Power supply Microphone mixing input MIC IN Channel L output LOUT Non connect Non connect Channel L input...
Page 43 MX-K50 KA3082 (IC401, IC402) : DC motor driver 1.Pin layout DRIVER OUT PRE DRIVER LOGIC SWITCH 2.Pin function Pin No. Function Symbol Ground Output 1 Phase compensation VCTL Motor speed control Input 1 VIN1 Input 2 VIN2 SVCC Supply voltage (Signal)
Page 44 MX-K50 VICTOR COMPANY OF JAPAN, LIMITED AUDIO & COMMUNICATION BUSINESS DIVISION PERSONAL & MOBILE NETWORK BUSINESS UNIT. 10-1,1chome,Ohwatari-machi,Maebashi-city,371-8543,Japan Printed in Japan (No.21121) 200211...

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JVC MX-K50 Service Manual

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