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JVC AV-21L31/ME Service Manual

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SERVICE MANUAL
DISPLAY
CHANNEL
CLOSED
CAPTION
TV/VIDEO
PICTURE MODE
CHANNEL SCAN
ECO SENSOR
RM-C248-2C
CONTENTS
SPECIFICATIONS ....................................................................................................................................2
a
OPERATING INSTRUCTIONS (APPENDIX)
SAFETY PRECAUTIONS .........................................................................................................................3
FEATURES ..............................................................................................................................................4
FUNCTIONS .............................................................................................................................................5
SPECIFIC SERVICE INSTRUCTIONS ....................................................................................................6
SERVICE ADJUSTMENTS ....................................................................................................................14
STANDARD CIRCUIT DIAGRAM (APPENDIX) .................................................................................. 2-1
PARTS LIST ...........................................................................................................................................35
COPYRIGHT © 2002 VICTOR COMPANY OF JAPAN, LTD.
COLOR TELEVISION
AV-21L31
AV-25L31
POWER
MENU
VOLUME
MUTING
1
2
3
4
5
6
7
8
9
RETURN
0
100
OFF TIMER
RM-C248 REMOTE CONTROL UNIT
/ME
/ME
AV-21L31
AV-25L31
BASIC CHASSIS
CH
No. 51908
Mar. 2002

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Summary of Contents for JVC AV-21L31/ME

  • Page 1: Table Of Contents

    AV-21L31 AV-25L31 SERVICE MANUAL COLOR TELEVISION BASIC CHASSIS AV-21L31 AV-25L31 POWER DISPLAY MENU CHANNEL VOLUME CLOSED CAPTION MUTING TV/VIDEO PICTURE MODE CHANNEL SCAN RETURN ECO SENSOR OFF TIMER RM-C248 REMOTE CONTROL UNIT RM-C248-2C CONTENTS SPECIFICATIONS ............................2 OPERATING INSTRUCTIONS (APPENDIX) SAFETY PRECAUTIONS .........................3 FEATURES ..............................4 FUNCTIONS .............................5 SPECIFIC SERVICE INSTRUCTIONS ....................6...

  • Page 2: Specifications

    AV-21L31 AV-25L31 SPECIFICATIONS Contents Items AV-21L31 AV-25L31 Dimensions (W × H × D) 59.8cm × 46.8cm × 47.2cm 68.2cm × 53.84cm × 47.8cm Mass 22kg 30kg TV RF System CCIR(M) Color System TV Mode NTSC3.58, PAL-M, PAL-N VIDEO Mode NTSC3.58, PAL-M, PAL-N Stereo System BTSC (Multi channel Sound) Receiving Frequency...

  • Page 3: Safety Precautions

    AV-21L31 AV-25L31 SAFETY PRECAUTIONS 1. The design of this product contains special hardware, many circuits 8. When service is required, observe the original lead dress. Extra and components specially for safety purposes. For continued pro- precaution should be given to assure correct lead dress in the high tection, no changes should be made to the original design unless voltage circuit area.

  • Page 4: Features

    AV-21L31 AV-25L31 FEATURES s New chassis design enables use of an interactive on-screen control. s Built-in DIGITAL ECO MODE (ECONOMY, ECOLOGY). s Pure flat CRT produces fine textured picture in every detail. In accordance with the brightness in a room, the brightness and/or s Wide range voltage (110V ~ 220V) for AC power input.

  • Page 5: Functions

    AV-21L31 AV-25L31 FUNCTIONS FRONT PANEL REAR PANEL COMPONENT VIDEO-1 ( VIDEO-2 ) OUTPUT INPUT INPUT MONO MONO REMOTE CONTROL UNIT RM-C248-2C POWER DISPLAY MENU CHANNEL VOLUME CLOSED CAPTION MUTING TV/VIDEO PICTURE MODE CHANNEL SCAN RETURN ECO SENSOR OFF TIMER RM-C248 REMOTE CONTROL UNIT No.

  • Page 6: Specific Service Instructions

    AV-21L31 AV-25L31 SPECIFIC SERVICE INSTRUCTIONS DISASSEMBLY PROCEDURE REMOVING THE REAR COVER 1. Unplug the power supply cord. Å ı 2. Remove the 7 screws marked and 4 screws maked as shown in Fig.1. 3. Withdraw the Rear cover toward you. [CAUTION] •...
  • Page 7 AV-21L31 AV-25L31 PICTURE TUBE FRONT CABINET (×2) (×2) SPEAKER MAIN PWB (CRT SOCKET PWB) MAIN PWB (×2) (×2) SPEAKER PB STOPPER REAR COVER (×7) (×4) Fig.1 No. 51908...
  • Page 8 AV-21L31 AV-25L31 REMOVING THE CRT CRT CHANGE TABLE * Replacement of the CRT should be performed by 2 or more persons. • After removing the rear cover, chassis etc., 1. Putting the CRT change table on soft cloth, the CRT change table should also be covered with such soft cloth (shown in Fig.
  • Page 9 AV-21L31 AV-25L31 REPLACEMENT OF MEMORY IC 1. MEMORY IC (6) User setting This TV uses the following memory IC. Check the user setting values in Table 2, and if setting value is Memory IC: IC1702 on MAIN PW Board different, set the correct value. The memory IC memorizes data for correctly operating the video For setting, refer to the OPERATING INSTRUCTIONS.
  • Page 10 AV-21L31 AV-25L31 SETTING OF SYSTEM CONSTANT SET Setting value Setting item Setting content AV-21L31 AV-25L31 NTSC TRIPLE COLOR SYSTEM NTSC COMB TILT SUPER BASS B/B SOUND TUNER COLOR AUTO LOCK LONG WAIT SHORT WAIT Table 1 No. 51908...
  • Page 11 AV-21L31 AV-25L31 USER SETTING VALUES Setting item Setting value SUB POWER CHANNEL POSITION CH-02, AIR CHANNEL PRESET REFER TO OPERATING INSTRUCTIONS VOLUME 15 ± 2 TV/VIDEO COMPRESS (16:9) AUTO SHUTOFF CHILD LOCK BLUE BACK VIDEO-2 SET VIDEO LANGUAGE MONO SURROUND AI VOLUME ON SCREEN DISPLAY POSITION INDICATION...
  • Page 12 AV-21L31 AV-25L31 SERVICE MENU SETTING ITEMS Service menu Setting item Service menu Setting item 1. IF 1. VCO 5. PRESET 1. CB 2. DELAY POINT 2. ACL Do not adjust 3. MUS 4. MAT 2. VC 1. CUTOFF(R/G) 5. FCO 2.
  • Page 13 AV-21L31 AV-25L31 REPLACEMENT OF CHIP COMPONENT CAUTIONS 1. Avoid heating for more than 3 seconds. 2. Do not rub the electrodes and the resist parts of the pattern. 3. When removing a chip part, melt the solder adequately. 4. Do not reuse a chip part after removing it. SOLDERING IRON 1.

  • Page 14: Service Adjustments

    AV-21L31 AV-25L31 SERVICE ADJUSTMENTS ADJUSTMENT PREPARATION 1. You can make the necessary adjustments for this unit with either the remote control unit or with the adjustment equipment and parts as given below. 2. Adjustment with the remote control unit is made on the basis of the initial setting values, however, the new setting values which set the screen to its optimum condition may differ from the initial settings.
  • Page 15 AV-21L31 AV-25L31 ADJUSTMENT LOCATIONS MAIN PWB ASS'Y S783 S781 J773 J772 J771 J770 S784 S782 S780 FRONT S780 : MENU POWER SW S781 : CH– S782 : CH+ S783 : VOL– S901 CN001 S784 : VOL+ IC702 IC701 J801 J802 J803 J804 TU001 UPPER : FOCUS (F1)
  • Page 16 AV-21L31 AV-25L31 BASIC OPERATION IN SERVICE MENU 1. TOOL OF SERVICE MENU OPERATION Operate the SERVICE MENU with the remote control unit. 2. SERVICE MENU ITEMS With the SERVICE MENU,various settings (adjustments)can be made,and they are broadly classified in the following items of settings: •...
  • Page 17 AV-21L31 AV-25L31 SERVICE MENU SUB MENU 1. IF SERVICE MENU 1. IF 2. VC VCO (CW) ***** 3. DEF 4. VSM PRESET TOO HIGH 5. PRESET 6. AUDIO 1. VCO ABOVE REFERENCE 7. PLUG & PLAY (OFF) BELOW REFERENCE 2. DELAY POINT TOO LOW 1-7 : SELECT DISPLAY : EXIT...
  • Page 18 AV-21L31 AV-25L31 ADJUSTMENTS B1 POWER SUPPLY Measuring Item Test point Adjustment part Description instrument Check of Signal B1 (pin 1) 1. Receive a black and white signal. Generator GND (pin 5) 2. Connect a DC voltmeter between B1 and GND B1 POWER SUPPLY [CN00S...
  • Page 19 AV-21L31 AV-25L31 VC (VIDEO/CHROMA) CIRCUIT ADJUSTMENTS The setting (adjustment) using the remote control unit is made on the basis of the initial setting values. The setting values which adjust the screen to the optimum condition can be different from the initial setting values. •...
  • Page 20 AV-21L31 AV-25L31 Measuring Item Test point Adjustment part Description instrument Signal 2. DRIVE (R) Notes: Adjustment of WHITE generator DRIVE (G) • Proceed to the following adjustment after having completed the ad- BALANCE DRIVE (B) justment of LOW LIGHT WHITE BALANCE. Remote •...
  • Page 21 AV-21L31 AV-25L31 Measuring Item Test point Adjustment part Description instrument Remote 5. COLOR [Method of adjustment without measuring instrument] Adjustment control unit Notes: • Proceed to the following adjustment after having completed the ad- COLOR-I justment of SUB PICTURE. • Set PICTURE MODE (VSM) to “BRIGHT”. 1.
  • Page 22 AV-21L31 AV-25L31 Measuring Item Test point Adjustment part Description instrument Adjustment Signal 6. TINT [Method of adjustment without measuring instrument] generator Notes: SUB TINT-I • Proceed to the following adjustment after having completed the ad- Remote justment of SUB PICTURE. control unit •...
  • Page 23 AV-21L31 AV-25L31 DEFLECTION CIRCUIT ADJUSTMENTS The setting (adjustment) using the remote control unit is made on the basis of the initial setting values. The setting values which adjust the screen to the optimum condition can be different from the initial setting values. Note: Proceed to the following adjustment after having completed the adjustments of SUB BRIGHT and SUB PICTURE.
  • Page 24 AV-21L31 AV-25L31 Measuring Item Test point Adjustment part Description instrument Adjustment 3. VER. HEIGHT 9. Receive a NTSC cross-hatch signal. Signal 10. Select 3. VER. HEIGHT with the MENU &/^ key. 13. V. ZOOM generator V. HEIGHT 11. Set the initial setting value of 3. VER. HEIGHT with the MENU –/+ key.
  • Page 25 AV-21L31 AV-25L31 Measuring Item Test point Adjustment part Description instrument 23. Select 7. EW-PIN with the MENU &/^ key. Adjustment 7. EW-PIN Signal 24. Set the initial setting value of 7. EW-PIN with the MENU –/+ key. generator SIDE PIN 25.
  • Page 26 AV-21L31 AV-25L31 Measuring Item Test point Adjustment part Description instrument 32. Select 9. UP CORNER with the MENU &/^ key. Adjustment 9. UP CORNER Signal 10. DW CORNER 33. Set the initial setting value of 9. UP CORNER with the MENU –/+ generator CORNER key.
  • Page 27 AV-21L31 AV-25L31 [COMPRESS (16 : 9): ON ] Measuring Item Test point Adjustment part Description instrument Adjustment Signal 13. V. ZOOM 1. Receive a NTSC cross-hatch signal. generator 2. VER. HEIGHT 2. Select COMPRESS from the MENU and set COMPRESS to ON. V.
  • Page 28 AV-21L31 AV-25L31 [VIDEO-2 SET: COMPONENT] Measuring Item Test point Adjustment part Description instrument Adjustment 5. HOR. POSITION 1. Receive a NTSC circle pattern signal to VIDEO-2 terminal. Signal 2. Select VIDEO-2 SET from the MENU and set VIDEO-2 SET to generator H.
  • Page 29 AV-21L31 AV-25L31 PRESET SETTING • Do not adjust 5. PRESET in the SERVICE MENU as it requires no adjustment. [SUB MENU 5. PRESET] Initial setting value Setting item Variable range AV-21L31 AV-25L31 IFLH AFCW 00/10/01 50 – 95 READ STATUS —...
  • Page 30 AV-21L31 AV-25L31 PURITY ADJUSTMENT Note: The final adjustment of CONVERGENCE must be done after the FOCUS adjustment. (CONVERGENCE is changed by FOCUS adjustment.) When makes difference by FOCUS adjustment, should be WEDGE DEFLECTION reconfirming PURITY adjustment. YOKE 1. Demagnetize CRT with the demagnetizer. 2.
  • Page 31 AV-21L31 AV-25L31 CONVERGENCE ADJUSTMENTS [AV-21L31 STATIC CONVERGENCE ADJUSTMENT 1. Input a crosshatch signal. 2. Using 4-pole convergence magnets, overlap the red and blue lines in the centre of the screen (Fig. 4) and turn them to magenta (red/blue). 3. Using 6-pole convergence magnets, overlap the magenta(red/blue) (FRONT VIEW) and green lines in the center of the screen and turn them to white.
  • Page 32 AV-21L31 AV-25L31 CONVERGENCE ADJUSTMENTS [AV-25L31 STATIC CONVERGENCE ADJUSTMENT 1. Input a crosshatch signal. (FRONT VIEW) 2. Using 4-pole convergence magnets, overlap the red and blue lines in the centre of the screen (Fig. 7) and turn them to magenta (red/blue). 3.
  • Page 33 AV-21L31 AV-25L31 SELF-CHECK FUNCTIONS 1. Outline This model has self-check functions given below.When an abnormality has been detected,the SUB POWER is turned off and both ECO and ON TIMER LEDs flash to inform of the failure.An abnormality is detected by the signal input state of the control line connected to the microcomputer. 2.
  • Page 34 AV-21L31 AV-25L31 SERVICE NOTE : No. 51908...

  • Page 35: Parts List

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

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Av-25l31/me