JVC-THA25-ddcs-sm维修电路原理图.pdf

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1、SERVICE MANUAL COPYRIGHT 2003 VICTOR COMPANY OF JAPAN, LIMITED No.MB143 2003/12 DVD DIGITAL CINEMA SYSTEM MB143200312 TH-A25 TABLE OF CONTENTS 1PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2、1-3 2SPECIFIC SERVICE INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5 3DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3、 1-6 4ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12 5TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4、 . . . . . 1-13 Area suffix US - Singapore UB - Hong Kong UW - Brazil,Mexico,Peru UX - Saudi Arabia UG - Turkey,South Africa,Egypt SOUND VOLUME SOURCE STANDBY STANDBY/ON DVD DIGIT AL CINEMA SYSTEM TH-A25 RadioFans.CN 收音机爱 好者资料库 1-2 (No.MB143) SPECIFICATION Designs pin #17,46,72,90 of UIC1 Check for

5、power-sense(5V)at FRONT PCB ;pin #77 of UIC1 When power on for FRONT PCB Check for High Voltage(5V) atMcom ;pin#74 of UIC1 Check low Voltage(0V) at EXPAND IC (M66010) ;pin#32 of UIC500 Check for connector from DSP PCB to FRONT PCB ;VCW7 Check normal Voltage at POWER PCB AZD1 (5.1V, 1/2W) Check patte

6、rn from VCW7 to pin#77 of UIC1 Replace Micom(UIC1) If High Voltage (5V), check for Circuit protection Check connector wire Assy of power P/T - MAIN PCB(7P,ACW3) MAIN PCB (8P,PW3) Replace AZD1 Check resistant from GND to pin #77 of MICOM(UIC1) if the short(0 ohm),to replace Micom(UIC1) Check for Inpu

7、t voltage at POWER PCB ;AIC1(7805) Replace AIC1 Check for circuit at Sub Trans ;PBD2, PT1, AFS3(Fuse) NO NO NO NO NO YES YES YES YES YES YES NO 1-14 (No.MB143) 5.1.2OUTPUT YES YES YES NO NO NO NO Check voltage at Main PCB ; VM, VL Check Voltage for CW7 ; 12V Check Connector PW1 Check ABD2,4 Check Au

8、dio channel at CW5 for input:5.1 channel Audio signal Check signal for FR/FL/C/W/RL/RR at MAIN PCB Check voltage for CW7(SPK Relay) ;High(5V) Check Q4,Q5 Check circuit for AMP channel ;Out ports of FIC6, IC7, RIC5 Reference to NEXT page ; A position Check circuit for Speak Relay (No.MB143)1-15 5.1.3

9、Protection(When High Voltage at Protectiion port) 5.1.3.1In this case LOW for, Base port of Q12(R2003 TR) at MAIN PCB NO NO NO NO NO YES YES YES YES YES A Check Voltage for Main AMP of Main PCB VM, VL Check voltage for IC4 -12V Check circuit for voltage(-12V) Check ABD2,4 Check circuit for DC Voltag

10、e Replace P/T, Q15 Check circuit for Diode behind position Check normal condition for Q15(C945) ;temperature-sense S/W be operated in the Power Trans is Turn on Check DC Voltage for Speaker port Check the parts is normal? ;ZD6,ZD5(3.9V) Check electric potention for PBD1, ABD1, PD3 at DVD Power PCB ;

11、R33,R36(27K) R34,R37 (150 Ohm) 1-16 (No.MB143) 5.1.3.2In this case LOW for Base of Q13(A733) at Main PCB 5.1.3.3Check the Connector Wire Assy Connectin of each PCB Check the Turn on for channel of Q35(C945) Check circuit for channel(Turn on) according feedback Aposition of previous page ;DVD MECHA -

12、 Main PCB (8P,PW3) ;POWER TRANS - Main PCB (ACW3) (No.MB143)1-17 5.2DVD Servo parts 5.2.1Initial operation after power ON (DVD Dual)(DVD single) Y Y 4 3 Y N N N Disc present or not Disc present POWER ON CD or DVD judgement DVD single or Dual layer judgement CD or CDRW judgement DVD single initial se

13、tting DVD Dual initial setting To Each disc playback CD initial setting CDRW initial setting DVD Single Dual CD CDCDRW Is Tray closed? Tray close operation. about 3sec. Is Tray closed? Stop Close operation. Wait Open Command from MPEG Laser Off Monitor Display=NO DISC Pick up headinitial position. 1

14、-18 (No.MB143) 5.2.2Play operation Play Disc Motor forced accelleration Repeat seveal times Change Disc Type Focus Seach Track servo ON CLV servo ON Read TOC Automatic Adjustment Automatic Adjustment is done once when the disc is replaced Is focus servo on? Search Picture appears 6 7 8 5 (No.MB143)1

15、-19 5.2.3PickUp Head Initial Position PickUp Head Initial Position (1) 1. Move Pick Up Head to inner direction until pin5 of MJ4=L (2) 2. If pin5 of MJ4=L, then move Pick Up Head to outer direction for a short time. (3) 3. Turn On the Laser of Pick Up Head to judge that disc is present or not. Does

16、Pick Up Move to inner direction? Does Pick Up Move to out direction again? Does Laser Turn On? Check voltage at pin8 of RCN1 is about 2.5V? Check BUS line between RIC1 and SIC1,SIC1 and MIC1 Is pulse of 2.5 +-2.5V developed at pin3,4 of MJ4? Is pulse of 2.5 +-2.5V developed at pin13 of SIC1 Is pin5

17、of MJ4 = L appeared? Replace Pick Up Head Check line between SIC1 and MJ4 Check connection between PCB and MECHA Check connection between PCB and MECHA Check peripheral circuit of SIC1 and DRIC1 Check BUS line between SIC1 and MIC1 N N N N N N N Y Y Y Y Y Y 3 OK 1-20 (No.MB143) 5.2.4Disc Presence/Ab

18、sense Judgment Disc Presence Judgment Turn On Laser Does lens move with UP/DOWN full stroke in focus direction? Is focus search voltage developed at pin 11 of SIC1 Check PI (pin36 of RU1) signal and FE (pin42 of RIC1)signal Y N N N No DiscOK Check connection between RIC1 and RCN1. Check BUS line RIC

19、1and SIC1. Check RIC1 Check peripheral circuit of DRIC1 Check BUS line between SIC1 and MIC1 Y YNo signal Normal Disc is presence 4 (No.MB143)1-21 5.2.5Disc Motor Does Not Rotate 5.2.6Focus Servo does not Work Disc Motor Does Not Rotate Is Voltage of 0V developed at pin15 of SIC1 Check peripheral ci

20、rcuit of SIC1. Check SIC1 Check peripheral circuit of DRIC1 Y N 5 (CD-RW) (DVD Dual)(DVD Single)(CD) Focus Servo does not Work Check peripheral circuit of SIC1 and RIC1 Check peripheral circuit of SIC1 and RIC1 Check Connection between PCB and MECHA Check peripheral circuit of DRIC1 Are FE(pin42 of

21、RIC1) and PI(pin36 of RIC1) normal? N Y 6 1-22 (No.MB143) 5.2.7Tracking Servo Does Not Work (CD) (DVD Single)(DVD Dual) (CD-RW) Tracking Servo Does not Work Check Voltage of PI(pin36 of RIC1) is normal Is TE(pin41 of RIC1) normal? Check peripheral circuit or RCN1 and DRIC1 Check connection between P

22、CB and MECHA Disc Judgment Error Check peripheral circuit or RIC1 Change PickUp or RIC1 Change SIC1 Y Y N N 7 (No.MB143)1-23 5.2.8CLV Servo Does Not Work CLV Servo Does not Work Is XSRFIN(pin2 of SIC1) normal? Is RF(pin21 of RCN1) normal? Check connection between PCB and MECHA Check peripheral circu

23、it of SIC1 Check peripheral circuit of DRIC1 Check peripheral circuit of RIC1 8 N N Y Y 1-24 (No.MB143) 5.3DVD MPEG Parts 5.3.1Initial operation after NO N N Y Y Y Y Y N N N N WAIT 2 3 POWER ON Check Reset Voltage at 24pin of U13 Check Servo parts and MPEG ATAPI Line Check Servo spindle motor parts

24、Check Pick up Lens and Pick up Flat Cable LOGO ON NO DISC DISPLAY (in time of absence) Loading Play OK Audio out/ in normal (in time of presence) (No.MB143)1-25 5.3.2Logo operation 5.3.3Audio operation N Y Y Y 2 Check 27MHZ crystal FIg.1 Check 114MHZ(pin 102 of U13) Video OK Check Video signal of VQ

25、1,VQ3,VQ4,VQ5,VQ6 Fig.1 OK Check Voltage of REG2 2.85V REG3 3.50V N N Y Y 3 Check NEW DSP Parts Check Main AMP parts Check Audio Digital signal at pin 33,36,37 of U13 Audio out OK (No.MB143) AV & MULTIMEDIA COMPANY AUDIO/VIDEO SYSTEMS CATEGORY 10-1,1chome,Ohwatari-machi,Maebashi-city,371-8543,Japan VICTOR COMPANY OF JAPAN, LIMITED WPC Printed in Japan