JVC AV-21L31/ME, Service Manual

Page 1: ...NEL VOLUME OFF TIMER TV VIDEO PICTURE MODE CHANNEL SCAN ECO SENSOR MUTING RETURN 1 2 3 4 5 6 7 8 0 9 CLOSED CAPTION 100 AV 21L31 ME AV 25L31 ME RM C248 2C CONTENTS a SPECIFICATIONS 2 a OPERATING INSTRUCTIONS APPENDIX a SAFETY PRECAUTIONS 3 a FEATURES 4 a FUNCTIONS 5 a SPECIFIC SERVICE INSTRUCTIONS 6 a SERVICE ADJUSTMENTS 14 a STANDARD CIRCUIT DIAGRAM APPENDIX 2 1 a PARTS LIST 35 ...

Page 2: ... 3 57MHz PAL N 3 58MHz Aerial Input Terminal 75Ø Unbalanced Power Input AC110 220V 50 60Hz Power Consumption 115W Max 75W Avg 150W Max 90W Avg Picture Tube Visible size 51cm measured diagonally Visible side 61cm measured diagonally High Voltage 29kV 1 5kV at cut off in service mode 31kV 1 5kV at cut off in service mode Speaker 5 12cm Oval type 2 Audio Output 5W 2 Video Audio Input 1 2 3 Video 1 3 ...

Page 3: ...s or alternatives approved by the manufacturer of the complete product 7 Do not check high voltage by drawing an arc Use a high voltage meter or a high voltage probe with a VTVM Discharge the picture tube before attempting meter connection by connecting a clip lead to the ground frame and connecting the other end of the lead through a 10kØ 2W resistor to the anode button 8 When service is required...

Page 4: ...n also be rearranged auto matically s Built in DIGITAL ECO MODE ECONOMY ECOLOGY In accordance with the brightness in a room the brightness and or contrast of the picture can be adjusted automatically to make the optimum picture which is easy on the eye s Built in OFF TIMER RETURN MAIN DIFFERENCE LIST MODEL No AV 21L31 ME AV 25L31 ME Part Name MAIN PWB ASS Y SCH 1501A M2 SCH 1502A M2 PICTURE TUBE A...

Page 5: ... CONTROL UNIT RM C248 2C RM C248 REMOTE CONTROL UNIT DISPLAY MENU POWER CHANNEL VOLUME OFF TIMER TV VIDEO PICTURE MODE CHANNEL SCAN ECO SENSOR MUTING RETURN 1 2 3 4 5 6 7 8 0 9 CLOSED CAPTION 100 VIDEO 1 INPUT OUTPUT COMPONENT VIDEO 2 INPUT V MONO L V Y V L MONO L CB R R R CR ...

Page 6: ...EMOVING THE SPEAKER After removing the rear cover 1 Remove the 2 screws marked Î and 2 screws maked as shown in Fig 1 2 Follow the same steps when removing the other hand speaker CHECKING THE MAIN PW BOARD 1 To check the back side of the Main PWB 1 Pull out the Main PWB Refer to REMOVING THE MAIN PW BOARD 2 Erect the Main PWB vertically so that you can easily check its back side CAUTION Before tur...

Page 7: ...No 51908 7 AV 21L31 AV 25L31 Fig 1 MAIN PWB CRT SOCKET PWB MAIN PWB PB STOPPER 4 B 2 2 E 2 E D 2 D C REAR COVER SPEAKER A SPEAKER FRONT CABINET PICTURE TUBE 7 ...

Page 8: ...eps The CRT change table should preferably be smaller that the CRT sur face and its height be about 35cm COATING OF SILICON GREASE FOR ELECTRICAL IN SULATION ON THE CRT ANODE CAP SECTION Subsequent to replacement of the CRT and HV transformer or repair of the anode cap etc by dismounting them be sure to coat silicon grease for electrical insulation as shown in Fig 5 1 Wipe around the anode button ...

Page 9: ...g values of the SYSTEM CONSTANT SET are the same as those indicated in Table1 If the value is different select the setting item with the MENU key and set the correct value with the MENU key 4 Press the DISPLAY key twice to return to the normal screen 5 Receive channel setting Refer to the OPERATING INSTRUCTIONS and set the receive channels channels preset 6 User setting Check the user setting valu...

Page 10: ...alue YES NO NTSC TRIPLE YES NO YES NO YES NO YES NO MU MA YES NO 000 255 000 255 AV 25L31 ME AV 21L31 ME COLOR SYSTEM COMB TILT SUPER BASS MSP B B SOUND TUNER COLOR AUTO LOCK LONG WAIT SHORT WAIT YES NO NO NO NTSC NO MU NO 001 001 SETTING OF SYSTEM CONSTANT SET Table 1 ...

Page 11: ...TIONS VOLUME 15 2 TV VIDEO TV VNR OFF COMPRESS 16 9 OFF AUTO SHUTOFF OFF CHILD LOCK OFF BLUE BACK ON VIDEO 2 SET VIDEO LANGUAGE ENG MONO SURROUND OFF AI VOLUME ON ON SCREEN DISPLAY POSITION INDICATION COLOR SYSTEM NTSC SOUND SYSTEM M PICTURE MODE VSM BRIGHT OFF TIMER 00 ECO SENSOR OFF CLOSED CAPTION OFF CC1 T1 USER SETTING VALUES Table 2 ...

Page 12: ...11 HOR PARALL 12 HOR BOW 13 V ZOOM 4 VSM PRESET 1 TINT BRIGHT STD SOFT 2 COLOR 3 BRIGHT 4 PICTURE 5 DETAIL Service menu Setting item SERVICE MENU SETTING ITEMS Service menu Setting item 5 PRESET 1 CB 2 ACL 3 MUS 4 MAT 5 FCO 6 BPS 7 IFLH 8 VID 9 STM 10 AFCW 11 VSW 12 FFI 13 AGC 14 CL 15 AKB 16 HBL 17 BKS 18 READ STATUS 19 VNR 6 AUDIO 1 STATUS 2 STANDARD SELECTION 3 FM PRESCALE 7 PLUG PLAY OFF Do no...

Page 13: ...part Transistors diodes variable resistors etc 1 Apply extra solder to each lead 2 As shown in the figure push the part with tweezers and alter nately melt the solder at each lead Shift and remove the chip part Note After removing the part remove remaining solder from the pattern REPLACEMENT OF CHIP COMPONENT 2 How to install Chip parts Resistors capacitors etc 1 Apply solder to the pattern as ind...

Page 14: ...ing value PICTURE MODE VSM BRIGHT VNR OFF BASS TREBLE BALANCE CENTER TINT COLOR BRIGHT PICTURE DETAIL CENTER MEASURING INSTRUMENT 1 DC voltmeter or Digital voltmeter 2 Oscilloscope 3 Signal generator Pattern generator NTSC 4 Remote control unit ADJUSTMENT ITEMS B1 POWER SUPPLY FOCUS ADJUSTMENT IF CIRCUIT ADJUSTMENTS Adjustment of VCO CW Adjustment of DELAY POINT AGC TAKE OVER VC VIDEO CHROMA CIRCU...

Page 15: ... TP 47G HV 4 1 GND B1 UPPER FOCUS F1 IC702 MAIN PWB ASS Y CRT SOCKET T 6 1 4 1 FRONT AV IN OUT HVT MAIN PWB ASS Y 1 6 1 1 6 5 S U LOWER SCREEN TU001 J770 S901 J773 S784 S782 S780 S783 S781 J772 J771 J804 J801 J802 J803 IC701 CN001 T PW DEG TP E S780 MENU S781 CH S782 CH S783 VOL S784 VOL POWER SW ...

Page 16: ...he keys 1 to 7 on the remote control unit and select the SUB MENU SCREEN from the SERVICE MENU See Fig 1 on the next page SERVICE MENU SUB MENU 1 IF 2 VC 3 DEF 4 VSM PRESET 5 PRESET 6 AUDIO 7 PLUG PLAY OFF 3 Method of Setting Once the setting values are set they are memorized automatically It must not adjust without inputting a signal 1 1 IF 1 VCO a 1 Key Select 1 IF b 1 Key Select 1 VCO c DISPLAY...

Page 17: ...W TRAPEZ 9 UP CORNER 10 DW CORNER 11 HOR PARALL 12 HOR BOW 13 V ZOOM SUB MENU 6 AUDIO 1 STATUS 2 STANDARD SELECTION 3 FM PRESCALE STEREO SAP MONO MENU 89 SELECT MENU OPERATE DISPLAY EXIT SUB MENU 3 DEF 60Hz NTSC3 58 1 CUTOFF R G V C NTSC3 58 1 VER SLOPE DEF MHz AUDIO 4 3 MENU 89 SELECT MENU OPERATE DISPLAY EXIT MENU 89 SELECT MENU OPERATE DISPLAY EXIT SUB MENU 5 PRESET NTSC3 58 1 CB PRESET 60Hz ME...

Page 18: ...ven when the screen gets darkened Adjustment of VCO CW VCO CW Item Measuring instrument Test point Adjustment part Description IF CIRCUIT ADJUSTMENTS Remote control unit Note Under normal conditions no adjustment is required 1 Select 1 IF from the SERVICE MENU 2 Select 1 VCO by pressing the 1 key on the remote control unit 3 Receive a broadcast signal 4 Check the characters color of the BELOW REFE...

Page 19: ...d 8 keys on the remote control unit 4 Press the 1 key on the remote control unit to produce a single hori zontal line 5 Turn the SCREENVR fully counterclockwise then slowly turn it clock wise to where a red blue or green color is faintly visible 6 Use the keys 4 and 7 or 5 and 8 on the remote control unit and adjust the other 2 colors to where the single horizontal line appears white 7 Turn the SC...

Page 20: ...with the MENU key 4 Set the initial setting value with the MENU key 5 If the contrast is not best with the initial setting value make fine adjustment until you get the best contrast 6 Press the DISPLAY key twice to return to the normal screen 4 PICTURE Adjustment of WHITE BALANCE High light Signal generator Remote control unit 2 DRIVE R DRIVE G DRIVE B Notes Proceed to the following adjustment aft...

Page 21: ... color 6 Press the DISPLAY key twice to return to the normal screen 5 COLOR Adjustment of SUB COLOR II Signal generator Oscilloscope Remote control unit 5 COLOR Method of adjustment using measuring instrument Notes Proceed to the following adjustment after having completed the ad justment of SUB PICTURE Set PICTURE MODE VSM to BRIGHT 1 Receive a NTSC color bar signal full field color bar 75 white ...

Page 22: ...the best tint 6 Press the DISPLAY key twice to return to the normal screen Mg B 0V R Cy Y W B G Adjustment of SUB TINT II Signal generator Oscilloscope Remote control unit 6 TINT Method of adjustment using measuring instrument Notes Proceed to the following adjustment after having completed the ad justment of SUB PICTURE Set PICTURE MODE VSM to BRIGHT 1 Receive a NTSC color bar signal full field c...

Page 23: ...he MENU key 4 Set the initial setting value of 1 VER SLOPE with the MENU key 5 Adjust 1 VER SLOPE to make A B with the MENU key B A Blanking line Adjustment of V POSITION Signal generator Remote control unit 2 VER POSITION 6 Select 2 VER POSITION with the MENU key 7 Set the initial setting value of 2 VER POSITION with the MENU key 8 Adjust 2 VER POSITION to make A B with the MENU key to be continu...

Page 24: ...Remote control unit Adjustment of H POSITION 5 HOR POSITION 15 Receive a NTSC circle pattern signal 16 Select 5 HOR POSITION with the MENU key 17 Set the initial setting value of 5 HOR POSITION with the MENU key 18 Adjust 5 HOR POSITION to make C D with the MENU key Signal generator Remote control unit Screen size 91 Picture size 100 C D Adjustment of H WIDTH 6 HOR WIDTH 19 Receive a NTSC cross ha...

Page 25: ...UM 8 EW TRAPEZ 26 Select 8 EW TRAPEZ with the MENU key 27 Set the initial setting value of 8 EW TRAPEZ with the MENU key 28 Adjust 8 EW TRAPEZ so that the vertical lines at the left and right edges on the screen are in parallel Signal generator Remote control unit Adjustment of V S CURVE 4 VER SCURVE 29 Select 4 VER SCURVE with the MENU key 30 Set the initial setting value of 4 VER SCURVE with the...

Page 26: ...corners on the screen are straight Signal generator Remote control unit Adjustment of H PARALLEL 11 HOR PARALL 37 Select 11 HOR PARALL with the MENU key 38 Set the initial setting value of 11 HOR PARALL with the MENU key 39 Adjust 11 HOR PARALL to optimize the parallelogram distortion Signal generator Remote control unit Adjustment of H BOW 12 HOR BOW 40 Select 12 HOR BOW with the MENU key 41 Set ...

Page 27: ...W PIN with the MENU key 10 Adjust 7 EW PIN so that the first vertical lines at the left and right edges on the screen are straight 7 EW PIN Adjustment of CORNER Signal generator Remote control unit 11 Select 9 UP CORNER with the MENU key 12 Set the initial setting value of 9 UP CORNER with the MENU key 13 Select 10 DW CORNER with the MENU key 14 Set the initial setting value of 10 DW CORNER with t...

Page 28: ...mote control unit C D VIDEO 2 SET COMPONENT Setting of VSM PRESET 1 TINT 2 COLOR 3 BRIGHT 4 PICTURE 5 DETAIL Remote control unit 1 Select 4 VSM PRESET from the SERVICE MENU 2 Select BRIGHT with the PICTURE MODE key 3 Adjust the MENU key and MENU key to reset the set val ues of 1 TINT 5 DETAIL to the values shown in the table 4 Respectively select the VSM PRESET mode for SOFT and STAND ARD and make...

Page 29: ...KB 0 1 0 0 16 HBL 0 1 0 0 17 BKS 0 1 1 1 18 READ STATUS 19 VNR 00 63 25 25 Setting item Variable range Initial setting value fixed 1 STATUS Do not adjust Do not adjust Do not adjust 2 STANDARD SELECTION 3 FM PRESCALE STEREO SAP MONO 34H 00H FFH 00H FFH 00H FFH 34H 34H AUDIO ADJUSTMENT Do not adjust 6 AUDIO 1 STATUS 2 STANDARD SELECTION 3 FM PRESCALE in the SERVICE MENU as it requires no adjustment...

Page 30: ...em horizontally Fig 2 7 Adjust the gap between two lugs so that the GREEN RASTER will come into the center of the screen Fig 3 8 Move the deflection yoke forward and fix the position of the deflec tion yoke so that the whole screen will become green 9 Insert the wedge to the top side of the deflection yoke so that it will not move 10 Input a crosshatch signal 11 Verify that the screen is horizonta...

Page 31: ...gence DYNAMIC CONVERGENCE ADJUSTMENT 1 Move the deflection yoke up and down and overlap the lines in the periphery Fig 5 2 Move the deflection yoke left to right and overlap the lines in the periphery Fig 6 3 Repeat 1 and 2 above and make best convergence After adjustment fix the wedge at the original position Fasten the retainer screw of the deflection yoke Fix the P C magnets with glue RED RED R...

Page 32: ...9 3 Using the VR on the deflection yoke match theYH CROSS Fig 10 and 12 4 Repeat the steps 1 and 3 and obtain an optimum convergence 5 Differential coil ADJUSTMENT In case where the horizontal lines of red and blue around the centre of both sides of the picture as shown in Fig 11 adjust the XV differ ence by using the differential coil on the top of the deflection yoke Fig 12 so as to minimize the...

Page 33: ...on An over current on the low B line is detected Operation of CRT NECK protec tion circuit The main microcomputer detects the possible abnormality at 30 msec intervals and judges the results in every 16 time Of the 16 times if NG is detected more than 9 times it is judged that there is an abnormality DITTO When an abnormality has been detected the SUB POWER is turned off While the SUB POWER is bei...

Page 34: ...34 No 51908 AV 21L31 AV 25L31 SERVICE NOTE ...

Page 35: ...Printed in Japan VP0203 SW AV 21L31 MEM 4 AV 25L31 MEM 4 VICTOR COMPANY OF JAPAN LIMITED HOME AV NETWORK BUSINESS UNIT 12 3 chome Moriya cho kanagawa ku Yokohama kanagawa prefecture 221 8528 Japan ...