JVC XVN55SL/UJ/UC/EB/E
Service Manual

XV-N50BK,XV-N55SL

3.12Check points for each error 3.12.1 Spindle start error (1) Defective spindle motor � Are there several ohms resistance between each pin of CN101 "5-6","6-7","5-7"? (The power supply is turned off and measured.) � Is the sign wave of about 100mVp-p in the voltage had from each terminal? [ CN101"9"(H1+),"10"(H1-),"11"(H2+),"12"(H2-),"13"(H3+),"14"(H3-) ] (2) Defective spindle motor driver (IC251) � Has motor drive voltage of a sine wave or a rectangular wave gone out to each terminal(SM1~3) of CN101"5,6,7" and IC251"2,4,7"? � Is FG pulse output from the terminal of IC251"24"(FG) according to the rotation of the motor? � Is it "L(about 0.9V)" while terminal of IC251"15"(VH) is rotating the motor? (3) Has the control signal come from servo IC or the microcomputer? � Is it "L" while the terminal of IC251"18"(SBRK) is operating? Is it "H" while the terminal of IC251"23"(/SPMUTE) is operating? � Is the control signal input to the terminal of IC251"22"(EC)? (changes from VHALF voltage while the motor is working.) � Is the VHALF voltage input to the terminal of IC251"21"(ECR)? (4) Is the FG signal input to the servo IC? � Is FG pulse input to the terminal of IC301"69"(FG) according to the rotation of the motor? 3.12.2 Disc Detection, Distinction error (no disc, no RFENV) � Laser is defective. � Front End Processor is defective (IC101). � APC circuit is defective. --- Q101,Q102. � Pattern is defective. --- Lines for CN101 - All patterns which relate to pick-up and patterns between IC101 � IC101 --- For signal from IC101 to IC301, is signal output from IC101 "21" (ASOUT) and IC101 "36"(RFENV) and IC101 "20" (FEOUT)? 3.12.3 Traverse movement NG (1) Defective traverse driver � Has the voltage come between terminal of CN101 "49" and "50" ? (2) Defective BTL driver (IC201) � Has the motor drive voltage gone out to IC201"17" or "18"? (3) Has the control signal come from servo IC or the microcomputer? � Is it "H" while the terminal of IC201"9"(STBY1) ? � TRSDRV Is the signal input? (IC301 "67") (4) TRVSW is the signal input from microcomputer? (IC301 "56") 3.12.4 Focus ON NG � Is FE output ? --- Pattern, IC101 � Is FODRV signal sent ? (R209) --- Pattern, IC301 "115" � Is driving voltage sent ? � IC201 "13", "14" --- If NG, pattern, driver, mechanical unit . � Mechanical unit is defective. 3.12.5 Tracking ON NG � When the tracking loop cannot be drawn in, TE shape of waves does not settle. � Mechanical unit is defective. Because the self adjustment cannot be normally adjusted, the thing which cannot be normally drawn in is thought. � Periphery of driver (IC201) Constant or IC it self is defective. � Servo IC (IC301) When improperly adjusted due to defective IC. (No.A0041)1-23