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JVC AV-28H20, Service Manual

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JVC AV-28H20 Service Manual Download Page 26

No. 51945

AV32H20EUS

AV28H20EUS

AV28H20EUB

26

     

Item

Measuring

instrument

Test point

Ad justment part

Description

V-SHIFT
Ad justment

Signal
generator

Remote
control unit

1. V- SHIFT

[FULL mode]
1.  Receive a circle pattern signal of vertic al frequency 50Hz.
2.  Select 4.DEF from the SERVICE MENU.
3.  Select 1.V-SHIFT  with the  FUNCTION UP / DOWN (    /    )  key.
4.  Adjust V-SHIFT to make 

A = B

.

5.  Check  the adjustment value above in other zoom mode. If it is a

wrong adjustment, re-adjust  in PANORAMIC  mode and  adjust
by 1.V-SHIFT.

6.  Press the MENU key and memoriz e the s et value.

V-SIZ E
adjustment

2.V-SIZE

1.  Receive a cross-hatch signal.
2.  Select 2.V-SIZE and  set the initial s etting value.
3.  Adjust V-SIZE and make s ure that the vertic al screen size of

the picture size is in the bellow table.

4.  Press the MENU key and memoriz e the s et value.
5.  Input a NTSC VIDEO signal (60Hz) from the EXT terminal,

and make sure that the vertic al screen s iz e is in the table
below.

6.  Press  the MENU  key and  memoriz e the s et value

Screen size

Picture size 100%

Picture

size

100%

Screen

size

A

B

   

ASPECT MODE

FULL

PANORAMIC

SUBTITLE

SCREEN

TOP

92%

87%

70%

SCREEN

 BOTTOM

92%

87%

83%

                    [ SCREEN SIZE ]

Summary of Contents for AV-28H20

Page 1: ...02 AV32H20EUS AV28H20EUS AV28H20EUB CONTENTS SPECIFICATIONS 2 SAFETY PRECAUTIONS 4 FEATURES 5 MAIN DIFFERENCE LIST 5 SPECIFIC SERVICE INSTRUCTIONS 6 SERVICE ADJUSTMENTS 12 PARTS LIST 31 OPERATING INSTRUCTIONS STANDARD CIRCUIT DIAGRAM 2 1 SERVICE MANUAL COLOUR TELEVISION BASIC CHASSIS MFⅡ Ⅱ Ⅱ Ⅱ ...

Page 2: ...n 187W Max 138W Avg standby 2 6W 178W Max 125W Avg standby 2 6W Aerial Input Term 75Ωunbalanced Coaxial Picture Tube Visible size 76cm Measured diagonally Visible size 66cm Measured diagonally High Voltage 31 0kV at zero beam current Speaker 16cm 4cm oval type 2 Audio Output 7 5W 7 5W EXT 1 EXT 2 EXT 3 Input Output 21 pin Euro connector SCART socket S Video Y 1Vp p POSITIVE Negative sync Provided ...

Page 3: ...l Low impedance TV OUT LINE OUT NC 4 AUDIO GND 5 GND B 6 AUDIO L input 500mVrms Nominal High impedance 7 B input 700mVB W 75Ω NC 8 FUNCTION SW SLOW SW Low 0 3V High 8 12V High impedance 9 GND G 10 SCL3 NC NC 11 G input 700mVB W 75Ω NC 12 SDA3 NC NC 13 GND R 14 GND YS NC NC 15 R C input R 700mVB W 75Ω C 300mVP P 75Ω only R only C 16 Ys input Low 0 0 4 High 1 3V 75Ω NC NC 17 GND VIDEO output 18 GND ...

Page 4: ...acements 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 10kΩ 2W resistor to the anode button 8 When service is r...

Page 5: ...ptional source at the EXT 2 output shown in figure MAIN DIFFERENCE LIST Model Name Part Name AV32H20EUS AV28H20EUS AV28H20EUB MAIN PWB ASSY SMF 1401A U2 SMF 1402A U2 POWER DEF PWB ASSY SMF 2401A U2 SMF 2402A U2 CRT SOCKET PWB ASSY SMF 3401A U2 SMF 3402A U2 FRONT CONTROL PWB ASSY SMF 8401A U2 SMF 8402A U2 FRONT CABINET ASSY LC10376 020A U LC10662 023A U LC10662 024A U DOOR LC20265 017A U LC20265 02...

Page 6: ... the rear cover 1 Remove the 3 screws marked D as shown in the Fig 1 2 Remove the 2 claws marked E under the CHASSIS as shown in Fig 2 3 Remove the AV TERMINAL BOARD slightly in the direction of arrow F as shown in Fig 2 REMOVING THE POWER DEF PWB After removing the rear cover After removing the rear CHASSIS 1 Remove the 3 screws marked G 2 Remove the POWER DEF PWB CHECKING THE PW BOARD To check t...

Page 7: ...AW CHASSIS AV TERMINAL BOARD B POWER CORD C 2 A 13 32 model D 3 2 FRONT CONTROL PWB 2 2 AV SW PWB This exploded view describes about AV28H20EUS AV28H20EUB Although AV32H20EUS are slightly different from this figure you can use the exploded view for disassembling the AV32H20EUS in same step as AV28H20EUS AV28H20EUB 12 28 models G 3 MICOM PWB 100Hz PWB ...

Page 8: ... arrows with a box type screw driver as shown in Fig 4 Since the cabinet will drop when screws have been removed be sure to support the cabinet with hands 4 After 4 screws have been removed put the cabinet slowly on cloth At this time be carefully so as not to damage the front surface of the cabinet shown in Fig 5 The CRT should be assembled according to the opposite sequence of its dismounting st...

Page 9: ...ith tweezers and remove the chip 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 alternately melt the solder at each lead Shift and remove the chip part Note After removing the part remove remaining solder from the pattern 2 How to install Chip parts Resistors capacitors etc 1 Apply solder to the pattern as i...

Page 10: ...d the SYSTEM CONSTANT SET screen of Fig 2 will be displayed 4 Check the setting values of the SYSTEM CONSTANT SET of Table 1 If the value is different select the setting item with the FUNCTION UP DOWN key and set the correct value with the FUNCTION key 5 Press the MENU key to memorize the setting value 6 Press the INFORMATION key twice and return to the normal screen 5 Setting of receive channels ...

Page 11: ...NSTALL BASS TREBLE BALANCE LANGUAGE ENGLISH HYPER SOUND BBE OFF ON EDIT MANUAL PRESET CH only The others BLANK SERVICE MENU SETING ITEMS TABLE 3 Setting item Setting value Setting item Setting value 1 IF 1 VCO 2 ATT ON OFF 4 DEF 1 V SHIFT 2 V SIZE 3 H CENT 4 H SIZE 5 TRAPEZ 6 EW PIN 7 COR PIN 8 COR UP 9 COR LO 10 ANGLE 11 BOW 12 V S CR 13 V LIN 2 V C 1 RGB BLK 2 WDR R 3 WDR G 4 WDR B 5 BRIGHT 6 CO...

Page 12: ...fore starting adjustment 5 If the receive or input signal is not specified use the most appropriate signal for adjustment 6 Never touch parts such as variable resistors transformers and condensers not shown in the adjustment items of this service adjustment 7 Preparation for adjustment presetting Unless otherwise specified in the adjustment items preset the following functions with the REMOTE CONT...

Page 13: ...F PWB FRONT CN001 AV SEL PWB TU NER CN002 W DEG 1pin B1 TP 91 2pin NC 3pin X ray 4pin X ray 5pin TP E 5 1 X FRONT CONTROL PWB 1 2 FRONT HV TP 47B CN014 CN013 SP R PW F901POWERSW SP L MICOM 100Hz CN002 F J J CN004 CN005 CN006 TP Y FRONT CONTROL PWB 2 2 FOCUS 2 SCR EEN FOCUS 1 32 MODEL SCR EEN FOCUS 28 MODEL UP DOWN S REMOCON LED V L HP R HVT ...

Page 14: ... 120Hzi SUBTITLE 100 120Hzi COMPRESS Fixed value 100 120Hzi 5 5 VSM PRESET This mode adjusts the initial setting values of COOL NORMAL and WARM VSM Video Status Memory 3 BASIC OPERATION OF SERVICE MENU 1 How to enter SERVICE MENU Press the INFORMATION key and the MUTING key of the REMOTE CONTROL UNIT simultaneously and the SERVICE MENU screen of Fig 1 will be displayed 2 Selection of SUB MENU SCRE...

Page 15: ... 8 COR UP 9 COR L O 10 A NGLE 11 B OW 12 V S CR 13 V LIN IF SER VICE MENU 1 VCO 2 ATT ON OFF 1 2 SELECT i EXIT SERVICE MENU 1 IF 2 V C 3 AUDIO 4 DEF 5 VSM PRESET 6 STATUS 7 PIP O FF 8 9 SHIPPING OF F 0 BUS F REE 1 9 SELECT EXIT i 1 ERR L IMIT 2 A2 ID THR 3 Q PEAK AUDIO 3 AUDIO 1 ERR LIMIT 100H ERROR RATE STORE i EXIT 1 IF VCO CO OL NO RMAL W AR M 5 VSM PRESET VSM PRESET NORMAL 1 CONT STORE i EXIT ...

Page 16: ...lect one from 2 V C 3 AUDIO 4 DEF and 5 VSM PRESET FUNCTION UP DOWN Key Select setting items FUNCTION Key Set adjust the setting values of the setting items MENU Key Memorize the setting value Before storing the setting values in memory do not press the CH TV POWER ON OFF key if you do the values will not be stored in memory INFORMATION Key Return to the SERVICE MENU screen 3 Do not setting 6 STAT...

Page 17: ...C volunteer Remote control unit CRT anode Chassis GND 1 RGB BLK 1 Receive a any broadcast 2 Push the ZOOM key and select the FULL mode 3 Select 2 V C from the SERVICE MENU 4 Select 1 RGB BLK with function UP DOWN key 5 Press the function key to find the cut off screen Black screen 6 Connect a DC voltmeter to CRT ANODE and chassis GND 7 Make sure that the voltage is DC 31 0kV 8 Press the function k...

Page 18: ...urning the FOCUS1 VR and adjust the picture so that the 3rd horizontal line from the upper may become uniform at the line center and its periphery 5 Carry out adjustment by repeating the steps 3 and 4 above 6 Make sure that when the screen is darkened the lines remain in good focus SCREEN Adjustment Signal generator SCREEN VR In HVT 1 Press a whole black signal 2 Press the ZOOM key and select the ...

Page 19: ...d key to bring the set values of 1 CONT 8 WDR B to the values shown in the table 4 Press the MENU key and memorize the set value 5 Respectively select the VSM PRESET mode for NORMAL and WARM and make similar adjustment as in 3 above 6 Press the MENU key and memorize the set value Refer to OPERATING INSTRUCTIONS for the PICTURE MODE 1 CONT 2 BRIGHT 3 SHARP 4 COLOUR 5 HUE 6 WDR R 7 WDR G 8 WDR B COO...

Page 20: ...een to the optimum condition can be different from the initial setting values Setting item Adjustment item Initial setting value 2 V C PAL SECAM NTSC 1 RGB BLK 2 WDR R 0000 3 WDR G 0000 4 WDR B Do not adjust 012 5 BRIGHT 0000 6 CONTRAST 0060 7 COLOUR 0000 8 HUE 0020 9 SHARP Do not adjust 0007 10 VCO ADJ Do not adjust 11 VID AGC Do not adjust 0000 12 SYC SLI Do not adjust 0007 13 A MOVIE Do not adj...

Page 21: ...f the white balance is good SUB BRIGHT adjustment Remote control unit 5 BRIGHT 1 Receive any broadcast 2 Select 2 V C from the SERVICE MENU 3 Select 5 BRIGHT with the FUNCTION UP DOWN key 4 Set the initial setting value with the FUNCTION key 5 If the brightness is not the best with the initial setting value make fine adjustment until you get the best brightness 6 Press the MENU key and memorize th...

Page 22: ...nitial set value make fine adjustment until you get the best colour 6 Press the MENU key and memorize the set value SECAM COLOUR SECAM COLOUR 1 Receive a SECAM broadcast 2 Make fine adjustment of SECAM COLOUR in the same manner as for above NTSC 3 58 COLOUR 1 Input a NTSC 3 58MHz COMPOSITE VIDEO signal from the EXT terminal 2 Make similar fine adjustment of NTSC 3 58 COLOUR in the same manner as f...

Page 23: ...t the initial setting value of SECAM COLOUR with the FUNCTION key 3 Adjust SECAM COLOUR and bring the value of A in the illustration to the values as shown given billow Voltage difference between white W and blue B 4 Press the MENU key and memorize the setting value NTSC 3 58 COLOUR 1 Input a NTSC 3 58MHz COMPOSITE VIDEO signal full field colour bar with 75 white from the EXT terminal 2 Set the in...

Page 24: ...set NTSC 4 43 will be automaticallyset at the respective values 8 HUE Method of adjustment using measuring instrument NTSC 3 58 HUE NTSC 3 58 HUE 1 Input a NTSC 3 58MHz COMPOSITE VIDEO signal full field colour bar with 75 white from the EXT terminal 2 Select 2 V C from the SERVICE MENU 3 Select 8 HUE with the FUNCTION UP DOW N key 4 Set the initial setting value of NTSC 3 58 HUE with the FUNCTION ...

Page 25: ...00 0000 0000 0000 9 COR LO Corner Pin correction Low side 0000 0000 0000 0000 0000 0000 0000 0000 10 ANGLE Angle correction 0000 0000 0000 0000 0000 0000 0000 0000 11 BOW Bow shaped distortion correction 0000 0000 0000 0000 0000 0000 0000 0000 12 V S CR Do not adjust Vertical height correction 0000 0000 0000 0000 012 0000 0000 0000 13 V LIN Do not adjust Vertical Linearity 007 0000 0000 0000 017 0...

Page 26: ...MIC mode and adjust by 1 V SHIFT 6 Press the MENU key and memorize the set value V SIZE adjustment 2 V SIZE 1 Receive a cross hatch signal 2 Select 2 V SIZE and set the initial setting value 3 Adjust V SIZE and make sure that the vertical screen size of the picture size is in the bellow table 4 Press the MENU key and memorize the set value 5 Input a NTSC VIDEO signal 60Hz from the EXT terminal and...

Page 27: ...l screen size of the picture size is in the bellow table 4 Press the MENU key and memorize the set value 5 Input a NTSC VIDEO signal 60Hz from the EXT terminal and make sure that the horizontal screen size of the each ASPECT mode is in the below table 6 Press the MENU key and memorize the set value EW PIN adjustment 6 EW PIN 1 Select 6 EW PIN and set the initial setting value 2 Adjust EW PIN and m...

Page 28: ...WN key 2 Set the initial setting value of COR UP with the FUNCTION or key 3 Adjust COR UP and bring the straight line at the upper corner 4 Select 9 COR LO with the FUNCTION UP DOWN key 5 Set the initial setting value of COR LO with the FUNCTION or key 6 Adjust COR LO and bring the straight line at the low corner 7 Press the MENU key and memorize the set value 8 If the extreame upper lower corners...

Page 29: ... value of 13 V LIN with the FUNCTION key 4 Select 12 V S COR with the FUNCTION UP DOWN key 5 Set the initial setting value of 12 V S COR with the FUNCTION key 6 Adjust 13 V LIN and 12 V S COR so that the spaces of each line on TOP CENTER and BOTTOM become uniform NOTE Do not adjust PANORAMIC SUBTITLE mode At first the adjustment in 100Hz FULL mode should be done then the data for the other aspect ...

Page 30: ...AUDIOadjustment of the SERVICE MENU as it requires no adjustment If values had changed for the some reason set the initial values in the following table 3 AUDIO Do not adjust Setting item Variable range fixed value 1 ERR LIMIT 000H FF0H 100H 2 A2 ID THR 00H FFH 19H 3 Q PEAK 0000H 7FFFH ...

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