JVC AV-20N3 User's Manual
Contents
1. OPERATE DISP EXIT Variable range DELAY POINT AGC TAKE OVER AV 20N3 AV 20NMG3 AV 20NMG3B Description Input a black and white signal colour off Enter the SERVICE MENU Select 1 IF from the SERVICE MENU Select 2 DELAY POINT by pressing the 2 key on the remote control unit Set the setting values of the setting items as shown bellow table Then adjust the MENU or key until video noise disappears Turn to other channels and make sure that there are no imegularities Initial setting value No 52025 21 AV 20N3 AV 20NMG3 AV 20NMG3B VIDEO CHROMA CIRCUIT ADJUSTMENT The setting adjustment usingthe 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 Do not change the initial setting values of the setting items not listed in ADJUSTMENT Measuring instrument Test point Signal 1 generator Adjustment of WHITE BALANCE Low light CUT OFF R CUT OFF G Remote CUT OFF B control unit SCREENVR IN HV T 50Hz WI SELECT 1 OPERATE KEY ASSIGNMENT OF REMOTE CONTROL UNIT CUTOFF OFF HUNE OFF GCUTOFF B CUTOFF A B DRVE A B CUTOFR v B DRVE v GCUTOFF y Signal generator Adjustment of WHITE BALANCE High light 2 DRIVE R DRIVE B Remote con2. Note Afterremoving the part remove remaining solder from the pattern No 52025 31 AV 20N3 AV 20NMG3 AV 20NMG3B 32 No 52025
3. Alternate Check Method Plug the AC line cord directly into the AC outlet do not use a line isolation transformer during this check Use an AC voltmeter having 1000 ohms per volt or more sensitivity in the following manner Connect a 15000 10W resistor paralleled by a 0 1 5pF AC type capacitor between an exposed metal part and a known good earth ground water pipe etc Measure the AC voltage across the resistor with the AC voltmeter Move the resistor connection to each exposed metal part particularly any exposed metal part having a retum path to the chassis and measure the AC voltage across the resistor Now reverse the plug in the AC outlet and repeat each measurement Any voltage measured must not exceed 0 75V AC r m s This to 0 5mA AC r m s However in tropical area this must not exceed 0 3V AC r m s This corresponds to 0 2mA AC r m s ACVOLTMETER HAVING 1000 OR MORE SENSITIVITY PLACE THIS PROBE ON EACH EXPOSED 1500 Q 10W METAL PART GOODEARTH GROUND AV 20N3 AV 20NMG3 AV 20NMG3B FEATURES New chassis design enables use of an interactive on screen control Wide range voltage 110V 240V AC power input With AUDIO VIDEO INPUT amp OUTPUT terminal MUTING button can reduce the audio level to zero instantly Functional remote control to operate T V set for channel select volume control power ON OFF etc from a distance bus control utilizes sin
4. 52025 AV 20N3 AV 20NMG3 AV 20NMG3B Measuring MER instrument Testpoint Adjustment part Description Adjustment Remote 3 BRIGHT Receive any broadcast of Enter the SERVICE MENU SUB BRIGHT Select 2 from SERVICE MENU Select 3 BRIGHT with the MENU W Akey Set the initial setting value with the MENU key If the brightness is not the best with the initial set value make fine adjustment until you get the best brightness Adjustment Remote 4 CONT Receive any broadcast of Enter the SERVICE MENU SUB CONT Select 2 from SERVICE MENU Select 4 CONT with the MENU W Akey Set the initial setting value with the MENU key If the contrast is not the best with the initial set value make fine adjustment until you get the best contrast Adjustment Remote 5 COLOUR Method of adjustment without measuring instrument of control unit SUB COLOUR I PAL COLOUR 1 Receive a PAL broadcast 2 Enter the SERVICE MENU 3 Select 2 from the SERVICE MENU 4 Select 5 COLOUR with the MENU V A key 5 Set the initial setting value for PAL COLOUR with the MENU 1 key 6 If the colour is not the best with the initial set value make fine adjustment until you get the best colour SECAM COLOUR 1 Receive a SECAM broadcast 2 Make fine adjustment of SECAM COLOUR as previously NTSC 3 58 COLOUR 1 Receive a NTSC 3 58MHz broadcast 2 Make similar
5. key 10 As shown in Fig 1 adjust VER HEIGHT and make the vertical screen size 92 of the picture size with the MENU keys of remote control unit 11 Input a circle pattern signal 12 Select 2 HOR POSITION with the MENU V A key 13 Set the initial setting value of 2 POSITION with the MENU key 14 Adjust 2 HOR POSITION to make HzH as shown in Fig 2 with the MENU key No 52025 27 AV 20N3 AV 20NMG3 AV 20NMG3B Measuring 2 instrument Test point Adjustment Signal of VER LIN generator amp VER Remote SCURVE control unit VSM PRESET SETTING Measuring Test point instrument Setting of Remote VSM control unit PRESET BRIGHT TNT COLOUR BRIGHT CONT SHARP V A SELECT OPERATE EXIT 28 Adjustment part 4 VER LIN 5 VER SCURVE Adjustment part TINT COLOUR BRIGHT CONT SHARP Description When the vertical linearity has been deteriorated remarkably perform the following steps 15 Input across hatch signal 16 Select 4 VER LIN with the MENU V A key 17 Setthe initial setting value of 4 VER LIN with the MENU key 18 Select 5 VER SCURVE with the MENU V A key 19 Setthe initial setting value of 5 VER SCURVE with the MENU key 20 Adjust 4 VER LIN and 5 VER SCURVE so that the spaces of each line as shown in Fig 3 on TOP CENTER and BOTTOM become uniform Make sure that the adjustment is properly don
6. Move the deflection yoke forward and fix the position of the deflection yoke so that the whole screen will become green Ins ert the wedge to the top side of the deflection yoke so that it will not move PURITY MAGNETS Input across hatch signal NGET Verify that the screen is horizontal Shortlug Input red and blue raster signals make sure that purity is properly adjusted Bring the long lug over the short lug and position them horizontally Fig 2 FRONT VIEW GREEN RASTER CENTER Fig 3 No 52025 29 AV 20N3 AV 20NMG3 AV 20NMG3B STATIC CONVERGENCE ADJUSTMENT 1 Input a cross hatch signal Using 4 pole convergence magnets overlap the red and blue lines in the center of the screen Fig 1 and tum them to magenta red blue FRONT VIEW Using 6 pole convergence magnets overlap the magenta red blue and green lines in the center of the screen and turn them to white Repeat 2 and 3 above and make best convergence FRONT VIEW DYNAMIC CONVERGENCE ADJUSTMENT RED GREEN BLUE 1 Move the deflection yoke up and down and overlap the lines the periphery Fig 2 2 Move the deflection yoke left to right and overlap the lines in the periphery Fig 3 3 Repeat 1 and 2 above and make best convergence After adjustment fix the wedge at the original position FRONT VIEW Fasten the retainer screw of the deflection yoke Fix the 6 magnets with glue 30 No 5202
7. 16 No 52025 AV 20N3 AV 20NMG3 AV 20NMG3B Method of setting 1 VCO 1 Key Boe LSR O Select 1 IF 2 1 Silos dus EE E V E S BS CIT Select 1 VCO 8 The VCO CW screen will be displayed a allow mark when the AFC voltage is at a certain level DISPLAY As you press this key twice you will return to SERVICE MENU 2 DELAY POINT Select 1 IF Select 2 DELAY POINT MENU Key t n Set adjust the setting values of the setting items 4 DISP LAY Key KI EEATT When this is pressed twice you will returnto the SERVICE MENU 2 VIC 3 DEF and 4 VSM PRESET Select one from 2 V C 3 DEF and 4 VSM PRESET Select setting items Adjust the values ofthe items When this is pressed return to the SERVICE MENU 6 SE TUP TOUR Bypressing the 6 key you can change the ON or OFF should be OFF Should be OFF If it is ON then you tum the TV power off when you are turn the TV power on again The JVC s logo will be shown about 15 seconds automatically Qo MENU Key Select Language MENU t 6 Auto Search No 52025 17 AV 20N3 AV 20NMG3 AV 20NMG3B SERVICE MENU FLOW CHART SERVICE MENU SERVICE MENU 1 IF 2 3 DEF 4 VSM PRESET 5 PRESET 6 SETUP TOUR OFF 1 6 SELECT DISP EXIT kkk 6 SETUP TOUR By pressing 6 k
8. For setting refer to the SERVICE ADJUSTMENTS KEY ASSIGNMENT OF REMOTE CONTROL UNIT SYSTEM CONSTANT III PICTURE MODE key SYSTEMCONSTANT SET gt AMP TUNER VNR TEXT TABLE VOLUM PAM WA SELECT 1 OPERATE DISP EXT DISPLAY 6 Fig 2 Except for difference in body colour the Remote Control Unit RM C364G Y and RM C364 have exactly the same Functions 10 No 52025 AV 20N3 AV 20NMG3 AV 20NMG3B SETTING OF SYSTEM CONSTANT SET Setting value Setting item Setting contents AV 20N3 AV 20N3 D AV 20NMG3 AV 20NMG3B AV 20NMG3 A gt gt YES NO NO TUNER MUT MA MU Al ECO SENSOR LANGUAGE E R A P E R 3 E C MI gt B B SOUND Sn YES 10 204 gt 230 LOCK 250 240 COLOUR AUTO YES 055 INT MQSS YES NO TEXT RATE 10 4 920 gt 404 80 YES ARA CYL erm EA __ POS NEG vei oe ipse i e eee Table 1 AMP TUNER il USER SETTING VALUES Setting item Setting value settingitem _ Setting value SUB POWER LANGUAGE ENGLISH CHANNEL POSITION 1 POSITION CHANNEL PRESET Refer to OPERATING INSTRUCTION VOLUME About 10 Al ECO SENSOR EIE ON SCREEN DISPLAY POSITION INDICATION AUTO SHUTOFF picturemope vsm erer P Table 2 No 52025 11 AV 20N3 AV 20NMG3 AV 20NMG3B INITIAL SETTING VALUE OF SERVICE MENU 1 Adjustment of the SERVICE MENU is ma
9. RETURNtKy 7 8 DISPLAY key 9 CHANNEL key 10 POWER key 17 PICTURE MODE key CHANNEL AN VOLUME Number CH key 9 65 L C REMOTE CONTROL G4 MUTING key 45 MENU key MENU A key MENU key a9 VOLUME key 200 2000 nf pe Qo RM C364 GY Except for difference in body colour the Remote Control Unit RM C364GY and RM C364 have exactly the same Functions 6 No 52025 AV 20N3 AV 20NMG3 AV 20NMG3B MAIN DIFFERENCE LIST Intermediate am ee CER ee Model Name SIF Carter 32 5MHz 5 5MHz AV 20N3 B G 1 DIK PAL SECAM 31 5MHz 6 5MHz E R 32 0MHz 6 0MHz 32 5MHz 5 5MHz AV 20NMG3 B G D K M NET NTSC3 58 NTSC4 43 31 5MHz 6 5MHz 32 0MHz 6 0MHz No 52025 7 AV 20N3 AV 20NMG3 AV 20NMG3B SPECIFIC SERVICE INSTRUCTIONS DISASSEMBLY PROCEDURE REMOVING THE REAR COVER 1 Unplug power plug 2 As shown in figure remove the 6 screws marked screw marked 3 Withdrawthe rear cover toward you REMOVING THE MAIN PW BOARD After removing the rear cover 1 Slightly raise the both sides ofthe MAIN PW BOARD by hand 2 Withdrawthe MAIN PW BOARD backward If necessary take off the wire clamp connectors etc REMOVING THE SPEAKER After removing the rear cover 1 Asshownin figure remove the 2 screws marked 2 Foll
10. While watching the screen adjust the FOCUS VR to make the vertical and horizontal lines as fine and sharp as possible 3 Make sure that when the screen is darkened the lines remain in good focus IF CIRCUIT ADJUSTMENT Measuring HN instrument Test point Adjustment part Description Adjustment Signal ofVCO CW generator Q Please use signal generator which is correct proof about the sending frequency Remote control unit Input the PAL full colour bar 210 25MHz signal Enter the SERVICE MENU Select 1 IF fromthe SERVICE MENU VCO CW sex MHz Press 1 key andselect 1 VCO TOOHIGH Select VCO ADJUST with MENU A Y key ABOVE REFERENCE Press MENU key until the colour of the characters TOO A ORBE HIGH changes blue to yellow Then gradually press the MENU TOOLOW key until the TOO LOW changes yellow At this time confirm py AFTADJUST seo Qe that the value of VCO ADJUST is near 00 VCO ADJUST Do amp otadiust Select AFT ADJUST with MENU key Press MENU key until the characters JUST REFERENCE changes blue to yellow Press the DISPLAY key three times to return to normal screen JUSTREFERENCE BELOW REFERENCE TOO LOW ADJUST MENT ATTHS POINTISUSE ADJUST MENT POINT 20 No 52025 Measuring instrument Testpoint Adjustment part Adjustment Signal DELAY POINT of DELAY generator AGC TAKE OVER POINT Remote AGC control unit DELAY POINT UHF
11. fine adjustment of NTSC 3 58 COLOUR as previously NTSC 4 43 COLOUR When NTSC 3 58 adjustment completed NTSC 4 43 will be automatically set atthe respective values No 52025 23 AV 20N3 AV 20NMG3 AV 20NMG3B Measuring Test point Adjustment part instrument Adjustment Signal TP 47G R 5 COLOUR of SUB generator COLOUR I Oscillo TP E 4 PAL COLOUR scope ent gogKET Remote control unit SECAM COLOUR NTSC 3 58 COLOUR NTSC 4 43 COLOUR Description Method of adjustment using measuring instrument 1 Inputa PAL full field colour bar signal 75 white 2 Enter the SERVICE MENU 3 Select 2 VIC from SERVICE MENU 4 Select 5 COLOUR withthe MENU V A key 5 Set the initial setting value of PAL COLOUR with the MENU key Connect the oscilloscope between TP 47G and TP E Adjust PAL COLOUR to bring the value of A in the illustration to the voltage as shown given billow Voltage difference between W and G AV 20N3 14 AV 20N3 D AV 20NMG3 AV 20NMG 3B AV 20NMG J A 1 Input a SECAM full field colour bar signal 75 white Set the initial setting value of SECAM COLOUR with the MENU or key Adjust SECAM COLOUR to bring the value of A in the illustration to the voltage as shown given billow Voltage difference between W and G AV 20N3 8V AV 20N3 D AV 20NMG3 AV 20NMGB AV 20NMG J A Input a NTSC 3 58 full field colour bar signal 75 white Set the initi
12. set SY STEM CONSTANT SET It must notadjust without adjustment signals Fig 1 1 Press the DISPLAY key and the PICTURE MODE key of the REMOTE CONTROL UNIT simultaneously 6 SETUP TOUR OFF 1 6 SELECT DISP EXIT 2 SERVICE MENU screen of Fig 1 will be displayed 3 While the SERVICE MENU is displayed again press the DISPLAY key and SYSTEM CONSTANT I PICTURE MODE key simultaneously and the SYSTEM CONSTANT SET screen of Fig 2 wil be displayed 4 Check the setting values of the SYSTEM CONSTANT SET of Table 1 If the SYSTEM CONSTANT SET value is different select the setting item with the MENU W Akey and set 3 COLOUR uhi BILINGUAL NO the correct value with the MENU key TUNER MU 5 Press the DISPLAY key twice and retum to the normal screen ECO SENSOR YES LANGUAGE 1 5 Receive channel of setting Refer to the OPERATING INSTRUCTIONS and set the receive channels V A SELECT channels preset as described IT OPERATES DEP Ar 6 User Setting Check the user setting value of Table 2 and if setting value is different set SYSTEM CONSTANT the correct value For setting refer to the OPERATING INSTRUCTIONS SYSTEM CONSTANT SET 7 Setting of SERVICE MENU CF SOUND Verify the setting items of the SERVICE MENU and reset where necessary LOCK 180 COLOURAUTO ek ass MINT ALC NO TEXT RATE 20 V A SELECT 1 OPERATE DISP EXIT
13. wil be broken If any repair has been made to the chassis it is recommended that the B1 setting should be checked or adjusted See ADJUSTMENT OF B1POWER SUPPLY The high voltage applied to the picture tube must conform with that specified in Service manual Excessive high voltage can cause an increase in X Ray emission arcing and possible component damage therefore operation under excessive high voltage conditions should be kept to a minimum or should be prevented If severe arcing occurs remove the AC power immediately and determine the cause by visual inspection incorrect installation cracked or melted high voltage harness poor soldering etc To maintain the proper minimum level of soft X Ray emission components in the high voltage circuitry including the picture tube must be the exact replacements or altematives approved by the manufacturer of the complete product 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 10kO 2W resistor to the anode button When service is required observe the original lead dress Extra precaution should be given to assure correct lead dress in the high voltage circuit area Where a short circuit has occurred those components that indicate evidence of overheating should be replaced
14. will further relieve the manufacturer of responsibility for personal injury or property damage resulting therefrom Many electrical and mechanical parts in the products have special safety related characteristics These characteristics are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by using replacement components rated for higher voltage wattage etc Replacement parts which have these special safety characteristics are identified in the parts list of Service manual Electrical components having such features are identified by shading on the schematics and on the parts list in Service manual The use of a substitute replacement which does not have the same safety characteristics as the recommended replacement part shown in the parts list of Service manual may cause shock fire or other hazards Don t short between the LIVE side ground and ISOLATED NEUTRAL side ground or EARTH side ground when repairing Some model s power circuit is partly different in the GND The difference of the GND is shown by the LIVE L side GND the ISOLATED NEUTRAL side GND and EARTH side GND Dont short between the LIVE side GND and ISOLATED NEUTRAL side GND or EARTH side GND and never measure with a measuring apparatus oscilloscope etc the LIVE side GND and ISOLATED NEUTRAL side GND or EARTH side GND at same time If above note will not be kept afuse or any parts
15. 5 AV 20N3 AV 20NMG3 AV 20NMG3B REPLACEMENT OF CHIP COMPONENT CAUTIONS 1 Avoid heating for more than 3 seconds 2 Donot rubthe electrodes andthe resist parts of the pattern 3 When removing achip part melt the solder adequately 4 Donot reuse achip part after removing it B SOLDERING IRON 1 Use ahighinsulation soldering iron with athin pointed end of it 2 AS30wsoldering iron is recommended for easily removing parts B REPLACEMENT STEPS 1 How to remove Chip parts 2 How to install Chip parts Resistors capacitors etc capacitors etc Apply solder to the pattern as indicated in the figure af 2 Grasp the chip part with tweezers and place it on the solder Then heat and melt the solder at both ends of the chip part P Transistors diodes variable resistors etc 1 Apply solder to the pattern as indicated in the figure 2 Grasp the chip part with tweezers and place it on the solder 3 First solderlead as indicated in the figure 4 Then solder leads B and 1 As shown the figure push the part with tweezers altemately melt the solder at each end 2 Shift with tweezers and remove the chip part Transistors diodes variable resistors etc 1 Apply extra solder to eachlead SOLDER SOLDER 2 As shown in the figure push the part with tweezers and altemately melt the solder at each lead Shift and remove the chip part
16. AV 20N3 AV 20NMG3 AV 20NMG3B JVC SERVICE MANUAL COLOUR TELEVISION AV 20N3 AV 20N3 AV 20NMG3 AV 20NMG3B IAN 20NMG3 RM C364GY RM C364 CONTENTS B SPECIFICATIONS 444 B SAFETY PRECAUTIONS settee hh eee hh nn anan anan B FEATURES B FUNCTIONS OE B MAIN DIFFERENCE LIST n I I anan anan anan SPECIFIC SERVICE INSTRUCTIONS occ nm I I hh mehr B SERVICE ADJUSTMENTS B PARTS LIST m OPERATING INSTRUCTIONS Xx STANDARD CIRCUIT DIAGRAM 3s 5x rac ale 4 HOaaon N 1 COPYRIGHT 2002 VICTOR COMPANY OF JAPAN LTD No 52025 Jun 2002 AV 20N3 AV 20NMG3 AV 20NMG3B SPECIFICATIONS CONT ENTS ITEM AV 20N3 AV 20NMG3 AV 20 N3 D AV 20NMG3B Dimensions W X D 619mm X 458mm X 488mm 19kg TV RF System B G DK B G D K M RF Mode PAL SECAM PAL SECAM NTSC3 58 NTSCA 43 Colour System VIDEO Mode PAL SECAM NTSC3 58 NTSCA 43 Picture Tube Visible size 48cm measured diagonally High Voltage 26 5kV 1 5kV at zero beam current Receiving Frequency VHF VL 46 25MHz 168 25MHz VHF VH 175 25MHz 463 2 5MHz UHF 471 25MHz 863 2 5MHz Cable TVs of Mid X Z 51 510 CATV Super 511 520 amp Hyper 521 541 bands receivable VIF Carr
17. Adjustment of the IF circuits 2M IG den nob non Adjustment of the VIDEO CHRO MA circuit SIDER ree eerte eben aaa Adjustment of the DEFLECTION circuit 4 VSM PRESET Adjustment of the initial setting values of VSM condition as STANDARD SOFT and BRIGHT VSM Video Status Memory 5S PRESET teres yrs Adjustment of the RF circuit Do not adjust 6 SETUP TOUR OFF It should be able to select mode LANGUAGE and AUTO CH PRESET Should be OFF 9 Key operation of the SERVICE MENU SERVICE MENU Enter to SERVICE MENU Press the DISPLAY key and the PICTURE MODE key of the REMOTE CONTROL UNIT simultaneously Then enter the SERVICE MENU mode as shown in Fig 1 SEGUIRE 2 3 DEF 4 VSM PRESET Exit from SERVICE MENU 5 PRESET When complete the adjustment work press the DISPLAY key to return to the 6 SETUP TOUR OFF SERVICE MENU 1 6 SELECT DISP EXIT And then press the DISPLAY key again return to the normal screen Select SERVICE MENU In SERVICE MENU press the number 1 6 key of the remote control unit to select any of the adjustment items The colours which selected item characters are changed KEY ASSIGNMENT OF REMOTE CONTROL UNIT Fig 1 PICTURE MODE key DISPLAY key Except for difference in body colour the Remote Control Unit RM C364GY and RM C364 have exactly the same Functions
18. Always use the manufacturer s replacement components No 52025 9 Isolation Check Safety for Electrical Shock Hazard After re assembling the product always perform an isolation check on the exposed metal parts of the cabinet antenna terminals video audio input and output terminals Control knobs metal cabinet screwheads earphone jack control shafts etc to be sure the product is safe to operate without danger of electrical shock 1 Dielectric Strength Test The isolation between the AC primary circuit and all metal parts exposed to the user particularly any expos ed metal part having a retum path to the chassis should withstand a voltage of 3000V AC r m s for a period of one second Withstand a voltage of 1100V AC r m s to an appliance rated up to 120V and 3000V AC r m s to an appliance rated 200V or more for a period of one second This method of test requires a test equipment not generally found inthe service trade 2 Leakage Current Check Plug the AC line cord directly into the AC outlet do not use a line isolation transformer during this check Using a Leakage Current Tester measure the leakage current from each exposed metal part of the cabinet particularly any exposed metal part having a return path to the chassis to a known good earth ground water pipe etc Any leakage current must not exceed 0 5mA AC r m s However in tropical area this must not exceed 0 2mA AC
19. al setting value of NTSC 3 58 COLOUR with the MENU key Adjust NTSC 3 58 COLOUR to bring the value of A in the illustration to the voltage as shown given billow Voltage difference between W and G AV 20N3 MV AV 20N3 D AV 20NMG3 AV 20NMG 3B AV 20NMG 3 A When NTSC 3 58 is set NTSC 4 43 willbe automatically set at the respective values 24 No 52025 Adjustment of TINT I Adjustment of TINT I Measuring instrument Signal generator Remote control unit Signal generator Oscillo scope Remote control unit Test point Adjustment part 6 TINT NTSC 3 58 TINT NTSC 4 43 TINT TP 47G R TP E CRT SOCKET PWB 6 TINT NTSC 3 58 TINT NTSC 4 43 TINT AV 20N3 AV 20NMG3 AV 20NMG3B Description Method of adjustment without measuring instrument 1 Input a NTSC 3 58 full field colour bar signal 75 white 2 Enter the SERVICE MENU 3 Select 2 from SERVICE MENU 4 Select 6 TINT withthe MENU V A key 5 Set the initial setting value of NTSC 3 58 with the MENU key 6 If you cannot get the best tint with the initial setting value make fine adjustment until you get the best tint When NTSC 3 58 is set NTSC 4 43 willbe automatically set at the respective values Method of adjustment using measuring instrument 1 Input a NTSC 3 58 full field colour bar signal 75 white 2 Enter the SERVICE MENU 3 Select 2 from SERVICE MENU 4 S
20. cro computer So write the data in the micro computer in accordance with the following procedures before starting adjustment PROCEDURES 1 Turnthe POWEROFF 2 Replace the IC301 with anew one 3 While pressing MENU button and VOL button ON the FRONT CABINET simultaneously turn the POWER ON When the POWER is turned ON the datais written inthe micro computer immediately LOCATIONS OF FRONT PANEL BUTTONS AND LAMPS Jvc 00000 c MENU buttons CHANNEL buttons MENU buttons VOLUME buttons MENU buttons Al ECO sensor REMOTE CONTROL sens or ON TIMER lamp NANA MENU HANNEI ov vERPo ER POWER lamp MAIN POW ER button amp jeiejiee e SO 14 No 52025 AV 20N3 AV 20NMG3 AV 20NMG3B SERVICE ADJUSTMENTS BEFORE STARTING SERVICE ADJUSTMENT 1 There are 2 way of adjusting this TV One is with the REMOTE CONTROL UNIT and the other is the conventional method using adjustment parts and components The adjustment with the REMOTE CONTROL UNIT is made on the basis of the initial setting values The setting values which adjust the screen to its optimum condition may differ from the initial setting values Make sure that connection is correctly made to AC power Source Turn on the power of the set and equipment before use and start the adjustment procedures after waiting at least 30 minutes Unless otherwise specified prepare the most suitable rece
21. de on the basis of the initial setting values however the new setting values which set the screen in its optimum condition may differ from the initial setting 2 Do notchange the initial Setting Values of the Setting Adjustment items not listed In ADJUSTMENT 2 VIC Initial setting value Variable range PAL NTSC 3 58 NTSC 4 43 BLUE BLUE AV 20N3 46 AV 20N3 D 6 TINT 63 63 AV 20NMG3 AV 20NMG3B 8 AV 20NMG3 A 8 Fixed 8 Not Adj 32 31 VIDEO 15 Fixed 3 DEFLECTION Initial setting value Setting item Variable range fv 50Hz MODE fv 60Hz MODE E HOR 0 4 VSM PRESET VSM preset mode BRIGHT STANDARD SOFT 12 No 52025 p suene Lo sve ANNA WENN CUM NE um Nee ME WP prose 4 ae AV 20N3 AV 20NMG3 AV 20NMG3B 5 PRESET The items in the following table it is no requirement for adjustment If values had changed by the miss operation setthe initial setting values in the following table Colour System Do Not Adjust Initial setting value Fixed value Setting item SECAM NTSC 3 58 NTSC 4 43 a 7 C BPF 9 VIF DET LEVEL 11 IF AGC MIN 12 VIF AGC 13 VIF PMOD 19 VNR 20 RGB LIM 21 RGB LIMIT LEVEL 23 TEXT H POSITION Sound System Do Not Adjust No 52025 13 AV 20N3 AV 20NMG3 AV 20NMG3B REPLACEMENT OF 1C301 IF DECODER For IC301 IF DECODER of this model all data are written the mi
22. e on the screen of 60Hz mode NOTE Adjust to make both 50Hz amp 60Hz are the same v size and fine straight line When adjust again adjust 50Hz mode first When adjust in 60Hz mode only 60Hz mode 15 adjust Description Enter the SERVICE MENU Select 4 VSM PRESET fromthe SERVICE MENU Select BRIGHT with the PICTURE MODE key Adjust the MENU V A and MENU key to bring the set values of TINT SHARP to the values shown in the below table Respectively select the VSM PRESET mode for SOFT and STANDARD and make similar adjustment as in 3 above e VSMPRESET VSM BRIGHT STANDARD SOFT Setting Item om _ 09 ew 5 _ 15 m 15 11 12 No 52025 AV 20N3 AV 20NMG3 AV 20NMG3B PURITY CONVERGENCE ADJUSTMENT PURITY ADJUSTMENT 1 Demagnetize CRT with the demagnetizer UNS DEFLECTION Loosen the retainer screw of the deflection yoke Remove the wedges Input i i put a green raster signal from the signal generator and turn 46 the screen to green raster P C Move the deflection yoke backward ee TS P C MAGNETS Bring the long lug of the purity magnets on the short lug and P PURITY MAGNET position them horizontally Fig 2 4 4POLES convergence magnets 6 6 POLES convergence magnets Adjust the gap between two lugs so that the GREEN RASTER will come into the center of the screen Fig 3
23. elect 6 TINT withthe MENU V A key 5 Set the initial setting value of NTSC 3 58 with the MENU key 6 Connect the oscilloscope between TP 47G R and TP E 7 Adjust NTSC 3 58 TINT to bring the value of B in the ilustration to the voltage as shown given billow Voltage difference between W and Cy AV 20N3 49V AV 20N3 D AV 20NMG3 AV 20NMG 3B AV 20NMG J A When NTSC 3 58 is set NTSC 4 43 willbe automatically set at the respective values No 52025 25 AV 20N3 AV 20NMG3 AV 20NMG3B Measuring PR instrument Test point Adjustment part Description Adjustment Remote T SECAM Method of adjustment using measuring instrument ofSECAM Control unit BL ADJUST BLACK Signal Input a SECAM full field colour bar signal OFFSET generator Enter the SERVICE MENU Select 2 from SERVICE MENU Select 7 SECAM BL ADJUST with V AMENU key Set the initial setting value with the or MENU key Switch the Okey colour OFF and key colour ON on the remote control and make sure that there is no colour on the black and white screen If the black and white screen is not best with the initial setting value make fine adjustment until you get the best black and white screen While watching the screen adjust the value to be the same colour between ON amp OFF by ten key on the remote control unit KEY ASSIGNMENT OF REMOTE CONTROL UNIT KEY ASSIGNMENT OF REMOTE CONTROL UNT Press the DISPLAY k
24. ey 18 SUB MENU 1 IF IF 1 VCO 2 DELAY POINT 1 2 SELECT SUB MENU 2 V C 50Hz SELECT OPERATE SUB MENU 3 DEF DEF 1 VER POSITION 50Hz V A SELECT 1 OPERATE SUB MENU 4 VSM PRESET BRIGHT TINT COLOUR BRIGHT CONT SHARP V A 5 OPERATE SUB MENU 5 PRESET PRESET PAL 1 AX 50Hz Wi SELECT 1 OPERATE No 52025 VCO CW MHz TOOHIGH ABOVE REFERENCE JUST REFERENCE BELOW REFERENCE TOOLOW AFT ADJUST VCO ADJUST DISP EXT DELAYPOINT UHF AGCTAKE OVER 1 OPERATE DISP EXIT AV 20N3 AV 20NMG3 AV 20NMG3B ADJUSTMENT LOCATIONS CRT SOCKET PWB SOLDER SIDE TOP m f TP 47RIG TP 47G R CRT EARTH WIRE BRAIDED ASS Y MAIN PWB 1C702 MEMORY IC 1Pin TP 91 B1 UPPER FOCUS 2Pin NC LOWER SCREEN 3Pin X ray1 4Pin X ray2 5Pin TP E 7 No 52025 19 AV 20N3 AV 20NMG3 AV 20NMG3B ADJUSTMENTS B1 POWER SUPPLY Measuring instrument Test point Adjustment part Description Check of Signal TP 91 B1 1 Input a whole black signal B1 Power generator 4 5 2 Connect a DC voltmeter to TP 91 B1 and DO eie 3 Make sure that the voltage is DC116 5 2 0V meter FOCUS ADJUSTMENT Measuring 2 p instrument Test point Adjustment part Description Adjustment Signal FOCUS VR 1 Input a cross hatch signal of FOCUS generator In HVT 2
25. ey twice to retum to the normal screen 26 No 52025 DEFLECTION CIRCUIT ADJUSTMENT AV 20N3 AV 20NMG3 AV 20NMG3B 9 There 2 modes of adjustment setting value D 50Hz mode and 2 60Hz mode depending upon the kind of signals vertic al frequency 50Hz 60Hz When adjusted in mode D mode 2 will be automatically s et The setting adjustment usin gthe REMOTE CONTROL UNIT is made on the basis ofthe initial setting values The setting values which adjust the screen to the optimum condition can be different from the initial settin g values Measuring instrument Testpoint Ad justment part Adjustment Signal 1 VER POSITION of V HEIGHT generator 3 VER HEIGHT amp Remote V POSITION control unit SUB MENU 3 DEF DEF 1 VER POSITION 50Hz V A SELECT OPERATE DISP EXIT Screen size Screen Picture size 10096 T 1 I 1 1 I L Picture sze 100 Fig 1 Adjustment 2 HOR POSITION of HOR generator POSITION Remote control unit Description Input a circle pattem signal Enter the SERVICE MENU Select 3 DEF from SERVICE MENU Select 1 VER POSITION with the MENU V A Set the initial setting value with the MENU key Adjust V and V tobe equal with the MENU key as shown in Fig 2 Input a cross hatch signal Select 3 V HEIGHT with the MENU V A key Set the initial setting value with the MENU
26. gle chip ICs for IF V C DEF VSM PRESET PRESET amp SETUP TOUR By means of AUTO PROGRAM the TV stations can be selected automatically and the TV channels can also be rearranged automatically Built in ECO MODE ECONOMY ECOLOGY In accordance with the brightness in a room the brightness and of contrast of the picture can be adjusted automatically to make the optimum picture which is easy on the eye Built in ON TIMER RETURN amp CHILD LOCK SYSTEM BLOCK DIAGRAM 1C301 VIDEO CHROMA DECORDER 702 MEMORY 1C701 SCL1 SDA1 COMPUTER 4 No 52025 FUNCTIONS E FRONT PANEL HM REAR TERMINAL ODO li lt 52025 AV 20N3 AV 20NMG3 AV 20NMG3B 4 MENU buttons 2 CHANNEL buttons 3 VOLUME buttons Al ECO sensor 5 REMOTE CONTROL sensor 8 ON TIMER lamp 2 POWER lamp MAIN POWER button 9 AN INPUT terminal 9 HEADPHONE jack Q ANT Terminal 2 VIDEO INPUT Terminal 3 VIDEO OUTPUT Terminal 9 AUDIO INPUT Terminal AUDIO OUT PUT Terminal AV 20N3 AV 20NMG3 AV 20NMG3B E REMOTE CONTROL UNIT RM C364GY AV 20N3 AV 20N3 D AV 20NMG3 AV 20NMG3 A RM C364 AV 20NMG3B e ECO SENSOR key 2 SOUND SYSTEM key m 2 OR 19 pm Cx 3 COLOUR SYSTEM key COLOUR SO ND MODE 4 TVVIDEO key TV VIDEO 1 2 3 5 OFF TIMER key 6 CHANNEL SCAN key
27. ier 38 0MHz a Interm ediate 32 5MHz 5 5MHz 32 5MHz 5 5MHz 33 5 MHz 4 5MHz Frequency SIF Carrier 31 5MHz 6 5MHz 31 5MHz 6 5MHz 32 0MHz 6 0MHz 32 0 2 6 0MHz PAL 4 43 2 Colour Sub Carrier Frequency SECAM 4 40625MHz 4 25MHz NTSC 3 58MHz 4 43MHz Power Input Rated Voltage AC110 240V 50 60Hz Power Consumption 90W Max 60W Avg Audio Output 3W Aerial Input Terminal 759 Unbalanced 1V p p 75 Front Rear 500mV rms 4dBs High impedance q RCA X 2 Front Rear Output Video 1V p p 752 M Audio 500mV rms 4dBs Low impedance lt RM C364GY AV 20NMG3 AV 20NMG3 A Battery size R06 UM 3 2 RM C364G Y AV 20NMG3B RM C364 Battery size AA R06 UM 3X2 Remote Control Unit Design and specifications are subject to change without notice 2 No 52025 AV 20N3 AV 20NMG3 AV 20NMG3B EE PRECAUTIONS The design of this product contains special hardware many circuits and components specially for safety purposes For continued protection no changes should be made to the original design unless authorized in writing by the manufacturer Replacement parts must be identical to thos e used in the original circuits Service should be performed by qualified personnel only Alterations of the design or circuitry of the products should not be made Any design alterations or additions will void the manufacturer s warranty and
28. ow same steps when removing the other hand speaker CHECKING THE MAIN PW BOARD 1 Tocheck the back side of the PW Board 1 Pull out the MAIN PW Board Refer to REMOVING THE MAIN PW Board 2 Erect the PW Board vertically so that you can easily check the back side of the PW Board CAUTION When erecting the PW Board be careful sothat there will be no contacting with other PW Board Before turning on power make sure that the CRT earth wire and other connector are properly connected WIRE CLAMPING AND CABLE TYING 1 Be suretoclamp the wire 2 Never remove the cable tie used for tying the wires together Should it be inadvertently removed be sure to tie the wires witha new cable tie 8 No 52025 AV 20N3 AV 20NMG3 AV 20NMG3B FRONT CABI MAIN PWB No 52025 9 AV 20N3 AV 20NMG3 AV 20NMG3B REPLACEMENT OF MEMORY ICs 1 MEMORY ICs This model uses memory Cs This memory IC data are for proper operation of the video and deflection circuits When replacing memory ICs be sure to use ICs written with the initial values of data 2 PROCEDURE FOR REPLACING MEMORY ICs 4 SERVICE MENU 1 Power off 2NIC Switch the power off and disconnect the power plug from the wall outlet 3 DEF 4 SM PRESET 5 PRESET 2 Replace ICs Be sureto use memory ICs written with the initial data values 3 Power on Connect the power plug into the wall outlet and switch the power on 4 Check and
29. ption or input signal for adjustment 6 Never touch any adjustment parts which are not specified in the list for this adjustment VRs transforms condensers etc Preparation for adjustment Unless otherwise specified in the adjustment instructions preset the following functions with the REMOTE CONTROL UNIT User mode position PICTURE MODE VSM BRIGHT VNR OFF TINT COLOUR BRIGHT CONT SHARP CENTER BLUE BACK OFF OFF TIMER OFF Al ECO SENSOR OFF AUTO SHUT OFF OFF MEASURING INSTRUMENT AND FIXTURES 1 2 3 DC voltmeter or digital voltmeter Oscilloscope Signal generator Pattern generator PAL SECAM NTSC 4 Remote control unit ADJUSTMENT ITEMS Adjustment item B1 POWER SUPPLY FOCUS adjustment IF circuit adjustment Video Chroma circuit adjustment No 52025 Adjustment item VSM PRESET setting DEFLECTION circuit adjustment PURITY CONVERGENCE adjus tment 15 AV 20N3 AV 20NMG3 AV 20NMG3B BASIC OPERATION OF SERVICE MENU The adjustment using SERVICE MENU The following adjustment items use the SERVICE MENU in the series of the adjustment The adjustments are made on the basis of the initial setting values The adjustment values which adjust the screen to the optimum condition can be different from the initial setting values With the SERVICE MENU various settings can be made and they are broadly classified in the folowing items of settings ANNE E
30. trol unit 50Hz V A SELECT 1 OPERATE Adjustment part Description Input a black and white signal colour off Enter the SERVICE MENU Select 2 from the SERVICE MENU then select 1 CUT OFF and Set each value to initial setting value with 4 9 keys of the remote control unit Press the 1 key of the remote control unit to show the single horizontal line on screen 6 Turnthe SCREEN VR fully counter cloc kwise then slowly tum it clockwise to where one of a red blue or green colour is faintly vis ible Use keys 4 9 of the remote control unit and adjust the other 2 colours which except the appeared colour to where the single horizontal line appears white 8 Turn the SCREEN VR to where the single horizontal line glows faintly 9 Press the 2 key to turn off the single horizontal line 10 Press the DISPLAY key twice to retum to the normal screen R 408 027 co 9 1 CUT OFF Input a black and white signal colour off Enter the SERVICE MENU Select 2 from the SERVICE MENU Select 2 DRIVE R B wth MENU V A key and set each value to initial setting value with 4 and 7 or 6 and 9 keys of the remote control unit 5 Use the keys 4 and 7 or 6 and 9 to produce a white screen Press the DISPLAY key twice to retum to the nomal screen Variable Initial setting Adjustment item range value R 28 127 128 127 2 DRIVE 22
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