JVC AV-20N3 User manual

No. 52025
Jun. 2002
AV-20N3
AV-20NMG
3
AV-20NMG3
B
1COPYRIGHT © 2002 VICTOR COMPANY OF JAPAN, LTD.
AV-20N3/AV-20N3/D
AV-20NMG3/AV-20NMG3B
/AV-20NMG3
/-A
CONTENTS
!SPECIFICATIONS ････････････････････････････････
････････････････････････････････････････････････････････････････
･････････････････････････････････････････････････････････････
･･････････････････････････････････････････････････････････
･････････････････････････････ 2
!SAFETY PRECAUT IONS ････････････････････････････････
････････････････････････････････････････････････････････････････
･･･････････････････････････････････････････････････････
･･････････････････････････････････････････････
･･･････････････････････ 3
!FEATURES････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････････････････････････････････････
･･･････････････････････････････････
･･････
･･･ 4
!FUNCTIONS ････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････････････････････････････････････
･･････････････････････････････････
････
･･ 5
!MAIN DIFFERENCE LIST ････････････････････････････････
････････････････････････････････････････････････････････････････
･･･････････････････････････････････････････････････････
･･････････････････････････････････････････････
･･･････････････････････ 7
!SPECIFIC SERVICE INSTRUCTIONS ････････････････････････････････
････････････････････････････････････････････････････････････････
･････････････････････････････････････････････
･･････････････････････････
･････････････ 8
!SERVICE ADJUSTMENTS ････････････････････････････････
････････････････････････････････････････････････････････････････
･････････････････････････････････････････････････････
･･････････････････････････････････････････
･････････････････････ 15
!PARTS LIST ････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････････････････････････････････････
･････････････････････････････････
･･
･33
★OPERATING INSTRUCTIONS
★STANDARD CIRCUIT DIAGRAM ････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････････････････････
････････････････････････････････
････････････････2-1
SERVICE MANUAL
COLOUR TELEVISION
BASIC CHASSIS
CG
[
RM-C 36 4G Y ]
[ RM-C364 ]

No. 52025
A
V-20N3
A
V-20NMG3
A
V-20NMG3B
2
SPECIFICATIONS
CONT ENTS
ITEM AV - 20 N3
AV - 20 N3/D
AV-20NMG3
AV-20NMG3B
AV-20NMG3/-A
Dimen sions(W×H×D) 619mm×458mm×488mm
Mass 19kg
TV RF Syst em B/ G, I, D/ K B/ G, I, D/ K,M
RF Mode PAL / SECAM PAL / SECAM / NTSC3.58 / NTSC4 .43
Colour System
VIDEO Mode PAL / SECAM / NTSC3.58 / NTSC4 .43
Pi cture Tube Visi bl e 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～463.25MHz
UHF 471.25MHz～863.25MHz
CATV
Cab le TVs of Mid ( X-Z, S1-S10)
Super (S11-S20) & Hyper (S21-S41)
bands recei vable
VIF Carrier 38.0MHz
Intermediate
Freq uen cy SIF Carrier
32.5MHz (5.5MHz)
31.5MHz (6.5MHz)
32.0MHz (6.0MHz)
32.5MHz(5.5MHz) /33.5MHz (4.5MHz)
31.5MHz (6.5MHz)
32.0MHz (6.0MHz)
Colour Sub C arr ier Freq uen cy
PAL (4.43MHz),
SECAM (4.40625MHz / 4.25MHz)
NTSC (3.58MHz / 4.43MHz)
Power Input Rated Voltage AC110～240V, 50 / 6 0Hz
Power Consu mption 90W (Max) / 60W(Avg)
Spe aker 5cm×12 cm, Oval type ×2
Audio Output 3W (monaural )
Aer i al In pu t Termi n al 75ΩUnbalanced
Input Video 1V(p-p), 75Ω(Front / Rear)
Audio 500mV(rms) (-4dBs), Hi gh impedance,
RCA×2 (Front / Rear)
Output Video 1V(p-p), 75Ω
Audio 500mV( rms) (-4dBs), Low impedance,
Hea dphone jack 3.5mm mini jack
Remote Control Unit
RM-C3 64GY
(Battery s ize : AA / R 06 / UM -3×2)
[AV-20NMG3 / AV-20NMG3/-A]
: RM-C364G Y
[AV-20NMG3B]
: RM-C364
(Battery s ize : AA / R 06 / UM -3×2)
Design and specifications are subject to change without notice.

No.52025
A
V-20N
3
A
V-20NMG3
A
V-20NMG3B
3
SAFETY PRECAUTIONS
1. T he d esi gn of th is pr od uct con ta in s sp eci al har d wa re , ma ny
circuits and components specially for safety purposes. For
con tinu ed pr ot ection , n o chan g es sh ou ld b e ma de to the o rig inal
d esign un less a uth or ized i n w ri tin g by th e ma nu fact ur er.
Rep lacem en t p ar ts m ust b e i d ent ic al to thos e u sed i n th e origin al
circu it s. S er vi ce sho uld b e p er for med by qu alif ied p ers on nel
on ly.
2. Alte r ation s of t he desi g n or cir cui tr y of t he pr od ucts sh oul d not be
made. Any design alterations or additions will void the
m anu fact ur er's w arr a nt y and w ill f ur th er r eli eve t he ma nu factu r er
of r esp onsi b il ity for per so na l i njur y or p r op er ty d am ag e r esult in g
th er efr om .
3. M an y e l ectr ical an d mech anica l p ar ts i n th e pr od ucts ha ve
special safety-relat ed characteristics. T hese characteristics are
oft en no t e vi den t f r om visua l i nsp ecti on n or ca n t he pr o tect io n
aff or de d by th em nece ssar ily b e ob tai n ed b y u sin g r ep lacem en t
com po ne nts ra ted f or hi g he r vo l tag e, watt ag e, etc. R ep lacem en t
p arts wh ic h ha ve th ese sp eci al s afet y ch ar act er ist ics ar e
identified in the parts list of Servic e manual. El ec tric al
components having su ch features are identified by shading
on the sche matic s and by (!
!!
!) on the parts list in Service
manual. The us e of a sub stitu te r ep la cem en t w hich do es n ot
h ave th e sam e saf ety ch ar act er ist ics as t he r eco mm en de d
r eplac em ent par t sh own in th e p ar ts li st of S er vi ce m an ual m ay
cause shock, fire, or other hazards .
4. Do n't shor t between the LIVE side ground and ISOL ATE D
(NEUTRAL) side ground or EARTH side ground when
repairing.
Some model's power circuit is partly different in the GND. The
diff er enc e of th e G ND i s sho wn b y th e LIV E : ( ") side GND, the
ISO LATE D( NEUTR AL) : ( #) side G ND and EARTH : ($) side
GN D. Do n't sh or t b et we en th e LIV E si d e GND an d
ISO LATE D(NEUTRAL) side GND or EARTH sid e GND an d
n ever m ea sur e w it h a m ea sur ing a ppa r atus (oscillo scop e etc.)
th e LI VE si d e GND an d IS OLA TED(NE UTRAL ) sid e G ND or
EARTH side GND at the s ame time.
If above note will not be kept, a fuse or any parts will be broken.
5. If any repair has been made to the chassis, it is recommended
th at t he B1 set ting shou l d b e ch ecke d or adju ste d ( Se e
ADJUSTMENT OF B 1 POW E R SU PPLY) .
6. T he hi gh volta ge app lie d t o th e pi ctu r e tu be mu st con for m wit h
th at sp ecifi ed i n S er vice m an ual. E xcessi ve h i gh vo lt ag e ca n
cau se an i ncr e ase in X- Ray em issi on , ar ci ng an d possib le
component damage, therefore operation under excessive high
voltage conditions should be kept to a minimum, or should be
preve nt ed. If s evere arc in g occur s, r emove t he AC power
immed i ate ly an d de ter m ine th e ca use b y vi sua l i nsp ect io n
( in cor r ect in stal lat ion, cr acke d or m elte d hi gh vo lt age har n ess,
p oor so ld ering, et c.) . To m aint ain the p r ope r min im u m le vel of
sof t X-Ray em issi on, c omp on en ts i n th e hi gh vol tag e ci rcuitr y
includ ing t he pict ur e tu be must b e t he e xact r ep lacem e nts or
alte rn at i ves ap pr ove d b y th e ma nuf act ur er of th e c om plet e
pr od uct.
7. Do n ot c hec k high volt ag e b y dr awing an arc. Use a high volt ag e
m eter or a hi g h v ol tag e pr ob e wit h a V TVM . D ischa rg e th e
picture tube before attempting meter connection, by connecting
a clip le ad to th e gr ou nd f ra me a nd c onn ecti n g th e oth er end of
the lead through a 10kΩ2W resisto r to the an od e b utt on .
8. W hen se r vi ce i s r equ ir e d, ob ser ve th e or igi na l lea d dr ess. E xtra
pr ec aut i on sh ou ld b e g i ve n t o assur e cor rect l ea d dr ess in th e
hig h vol tag e ci rcui t a r ea. W her e a s hor t cir cui t h as occu rre d,
th ose co mp on ent s tha t indica te evide nce of ove r hea ti ng sho ul d
b e r e place d. A lwa ys u se th e ma nuf act ur er's r ep lacem en t
components.
9. Isolation Check
(Safety for Electrical Shock Hazard)
Af ter r e-ass emb lin g th e p r odu ct, alw ays per f orm an i solat io n
ch eck on the expo sed me tal p ar ts of t he cabi n et ( a nte nn a
ter m ina ls, vid eo /au di o i npu t and ou tpu t t er min al s, Con tr ol kn obs,
m etal cabin et, scr ewhe ad s, ea r ph one jack, con trol shaf ts, etc.)
to be su re th e p r odu ct i s s af e t o o pe r ate with ou t d an ger of
elect rical shoc k.
(1) Dielectric Strength Test
The i so lation be tw een the A C pr im a ry circu i t an d al l me tal p ar ts
exp ose d t o th e us er , p ar ti cul arl y an y e xp os ed met al p art h aving a
r etu rn p ath to t he chass is sho uld withs tan d a volt age of 3 000 V
AC (r.m.s.) for a period of one second.
( . . . . W it hstan d a vo lt ag e of 1 10 0V A C ( r.m. s.) t o an ap pl ianc e
r ate d up to 12 0V , an d 3 00 0V AC ( r.m. s.) to an ap plian ce r at ed
200V or more, for a period of one second.)
This method of test requires a test equipment n ot generally found
in t he ser vic e trad e.
(2) Leakage Current Check
Pl ug th e A C lin e c ord d ir ect l y in to th e A C ou tl et ( d o n ot use a lin e
isolati o n tr ansf or m er du r in g thi s ch eck.) . U sin g a " Lea kag e
Cur rent Teste r", me asur e th e lea kag e cu rre nt f rom each exp osed
m etal p ar t of the ca bi ne t, p art icu l arly any e xpos ed me tal p ar t
h aving a re turn pa th to t he ch assis , t o a kn own go od ea rt h
gr ou nd (wa ter pi p e, e tc.) . An y leaka ge cur ren t m ust n ot e xceed
0.5mA AC (r.m.s.).
Howeve r, in tr op ic al ar ea , th is mu st no t exce ed 0.2 mA AC
(r.m.s.).
"
""
"Alte rnat e Che ck M ethod
Pl ug th e A C lin e c ord d ir ect l y in to th e A C ou tl et ( d o n ot use a lin e
isolati o n tr an sfor m er during t hi s che ck.) . U se an AC vo lt me ter
h aving 1 00 0 oh ms pe r volt or m ore sens it i vi ty in th e fo llowing
m ann er. C on nec t a 1 50 0Ω10W res ist or par a ll e le d b y a 0 .1 5µF
AC -type c apa cit or bet we en an expo sed met al pa rt a nd a kno wn
g ood e ar th gr o un d ( wa ter pi pe , etc.) . M eas ur e th e A C vo lt ag e
acr oss th e r es ist or wi th th e AC vo l tm eter . M ove th e r esistor
con nec tion to e ach exp ose d me tal par t, p art i cular ly a ny exp osed
m etal p ar t havi n g a r etu rn pat h to t he ch assi s, an d m easu r e th e
AC vol tag e ac ro ss the r es ist or . N o w, re verse th e pl u g i n th e AC
ou tl et and r e pe at eac h m ea surem en t. An y volt ag e me asu re d
must not exc eed 0.75V AC (r.m. s.). This c orre sponds to 0.5mA
AC (r.m.s.).
Howeve r, in tropica l area, this must not exceed 0.3V AC ( r.m. s.).
This corresponds to 0.2mA AC (r.m.s.).
0.15μF AC-T YPE
1500 Ω10W
GOODEARTH GROUND
PLACE THIS PROBE
ON E A C H EX PO SE D
ME T AL PA RT
ACVOLTMETER
(HAVING 1000 Ω/V,
OR MOR E SENSIT IVITY)

No. 52025
A
V-20N3
A
V-20NMG3
A
V-20NMG3B
4
FEATURES
"New ch assi s d esi gn en abl es us e of an i nt er acti ve on- scr ee n c ont ro l.
"W ide r an ge volt age ( 1 10V ～240V) AC power input.
"With AUDIO / VI DE O INPUT & OUTPUT terminal.
"MUTING but ton can red uce th e a udio level to zero inst ant ly.
"Funct i on al r emote co ntrol t o o per a te T V set (f or ch ann el se lect, vol ume c on trol, p ow er ON /OF F, etc. ) f r om a d ist anc e.
"I
2C bu s con tr ol ut i lizes single chip ICs for IF, V /C, DE F. V SM PRES ET, PRESET & S ETU P TOUR.
"By m e ans of AU TO PROGRA M, th e T V s tati o ns c an b e s el ecte d aut om atica ll y a nd th e TV cha nn els can al so b e r ear ran ge d a ut om ati cal ly.
"Built- in E CO MO DE (ECONOMY, ECOLOG Y)
In acco rd anc e with th e br ig ht ness in a r oo m, th e br ig ht ness and / of con tr ast of th e p i ctur e can b e a dj ust ed au tom at ic all y to m ake th e
op ti mu m pi ctu re w hich is eas y on th e e ye.
"Built – in ON TIMER, RETURN + & CHILD LOCK.
SYSTEM BLOCK DIAGRAM
IC301
VIDEO/CHROMA
DECORDER
IC702
MEMORY
TU001
TUNER
IC701
MICRO
COMPUTER
SCL 1/SDA1
SCL 2/SDA2

No. 52025
A
V-20N
3
A
V-20NMG3
A
V-20NMG3B
5
FUNCTIONS
■
FRONT PANEL
■
REAR TERMINAL
MENU buttons
CHANNEL －/＋buttons
VOLUME －/＋bu tto ns
AI ECO sensor
RE MO TE CONTROL s ens or
ON TIMER lamp
POWER lamp
MAINPOWERbutton
A/V INPUT t ermin al
HE ADPHONE j ack
1
2
3
4
5
6
7
8
9
10
10 9 1 2 3 4 5 6 78
ANT Terminal
VIDEO INPUT Terminal
VIDEO OUTPUT Terminal
AUDIO INPUT T ermin al
AUDIO OUT PUT Terminal
1
2
3
4
5
2
3
4
5
1

No. 52025
A
V-20N3
A
V-20NMG3
A
V-20NMG3B
6
■
REMOTE CO NT RO L UNIT
E xce pt f or d if fer en ce i n bo dy co l our, t he R emote Cont r ol
Unit R M-C3 64G Y a nd R M- C36 4 h ave exa ctly th e sa me
Func tions.
ECO SENSOR ke y
SOUND SYSTEM key
COLO UR SY STEM ke y
TV/VIDEO key
OFF TIMER key
CHA NNE L SCAN k ey
RETURN＋key
DISPLAY key
CHANNEL key
POWER key
PICTURE MODE key
Number (CH.) key
－/－－key
MUTING key
MENU key
MENU ▲/▼key
MENU －/＋key
VOL UME－/＋key
RM-C364GY : AV-20N3 / AV-20N3/D / AV-20NMG3 / AV-20NMG3/-A
RM-C364 : AV-20NMG3B
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16

No. 52025
A
V-20N
3
A
V-20NMG3
A
V-20NMG3B
7
MAIN DIFFERENCE LIST
Part Name
Model Name Mai n PWB Remote Control Unit Fr ont Cabinet Rating Label
AV-20N3 SCG -1403A-H2 RM-C3 64GY-1H LC1 0438-027A-H LC2 0377-010B-H
AV-20N3/D SCG -1425A-H2
AV-20NMG3 SCG-1422A-H2 LC1 0438-029A-H
AV-20NMG3B RM-C3 64-1H LC10438-033A-H
AV-20NMG3/-A RM-C3 64GY-1H LC1 0438-029A-H LC20413-002B-H
Part Name
Model Name Picture Tube Inst Book Di gest Manual
AV-20N3 A48LWX10X LCT1188-001A-H LCT1189-001A-H
AV-20N3/D
AV-20NMG3 A48LDD095X LCT1196-001A-H LCT1197-001A-H
AV-20NMG3B
AV-20NMG3/-A
Item
Model Name TV RF System Co l o ur S y st em
[RF Mode]
Intermedi ate
Fr equency
[SIF C arri er ]
OSD Language
AV-20N3 B/G, I, D/K PAL / SECAM
32.5MHz (5.5MHz)
31.5MHz (6.5MHz)
32.0MHz (6.0MHz)
E / R
AV-20N3/D E / C / M / I
AV-20NMG3 B/G, I, D/K,M PAL / SECAM
NTSC3.58 / NTSC4.43
32.5MHz (5.5MHz)
33.5MHz (4.5MHz)
31.5MHz (6.5MHz)
32.0MHz (6.0MHz)
E / R / A / P
AV-20NMG3B
AV-20NMG3/-A

No. 52025
A
V-20N3
A
V-20NMG3
A
V-20NMG3B
8
SPECIFIC SERVICE INSTRUCTIONS
DISASSEMBLY PROCEDURE
REMOVING THE REAR COVER
1. U np lu g t he po we r plu g.
2. As sh own i n f i gure , r emove t he 6screws marked !
!!
!an d a
screw marked "
""
".
3. W i thdr a w t he r ear co ver to wa rd you .
REMOVING THE MAIN PW BOARD
"After removing the rear cover.
1. Sli ght l y r aise t he bo th si d es of t he M AIN PW BOAR D b y ha nd .
2. W i thdr a w t he M AIN PW B OAR D b ackw ard.
( If n ecess ar y, ta ke off the wir e cl amp, c onn ect or s etc. )
REMOVING THE SPEAKER
"After removing the rear cover.
1. As sh own in fi gu re, r em ove th e 2screws marked #
##
#.
2. F oll ow th e s am e st eps wh en r emoving th e oth er ha nd sp eak er .
CHECKIN G THE MAIN PW BOARD
1. T o ch eck the ba ck side of th e PW B oar d.
1) Pu ll out the MA IN PW Bo ar d. ( Ref er to RE MO VING TH E M AIN
PW B oard)
2) Er ect th e PW Boar d ve rt ic ally so th at you ca n easil y ch eck th e
b ack si de of th e PW B oar d.
[CAUTION]
"W hen e re cting th e PW Boar d, be car ef ul s o t hat th er e w il l b e n o
con tact in g with ot her PW Board.
"Before turning on power, make sure that the CRT earth wire and
oth er co nne cto r ar e p r ope rly c onn ect ed.
WIRE CLAMPING AND CABLE T YING
1. Be sure t o clamp the wire.
2. N ever r emo ve th e c abl e tie use d f or tying th e wire s to ge the r.
Sh oul d i t be inad ver te ntl y r emove d, b e su re to ti e th e wir es w it h a
new cable tie.

No. 52025
A
V-20N
3
A
V-20NMG3
A
V-20NMG3B
9
CRT SOCKET
PWB
FRONT CABI.
POWER
CORD
SP EAKE R
SP EAKE R
MAIN PWB
C
C
REAR
COVER
B
A
(×
××
×2)
(×
××
×1)
(×
××
×6)
(×
××
×2)

No. 52025
A
V-20N3
A
V-20NMG3
A
V-20NMG3B
10
REPLACEMENT OF MEMORY ICs
1. MEMORY ICs
Thi s mod el u ses me mo r y I Cs. Thi s me mo r y IC da ta ar e f or pr o per oper a tion of th e vi de o a nd d eflect io n cir cui ts.
W hen r ep la ci ng me mory ICs, b e su r e to us e ICs w rit ten wi th t he i niti al va lu es of dat a.
2. PROCEDURE FOR REPLACING MEMORY IC s
(1) Power off
Sw itch the p ow er of f an d di sco nn ect t he pow e r plu g f rom t he w all out l et.
(2) Replace ICs
Be sure to use memory ICs written with the initial data values.
(3) Power on
Con nect th e p ow er pl u g i nt o t he w all ou tlet and sw itch t he po we r on .
(4) Check and set SY STEM CO NSTANT SET
・
・・
・It must not adjust without adjustment signals.
1) Pr ess t he DI SPLAY ke y and th e PICTURE MODE key of the REMOTE
CONTROL UNIT simultaneously.
2) The SERVICE MENU screen of Fig. 1 will be displayed.
3) W hile th e SE RV ICE M ENU i s di spl ayed , ag ai n pr ess the DI SPLAY key and
PICTURE MODE ke y sim ulta neo usly, an d t he S YSTEM C ONSTA NT SE T
scr een of Fig. 2 w ill b e di spl a ye d.
4) C heck th e sett in g val u es of th e SYS TEM C ON STA NT SET of T abl e 1 If th e
value is diff erent, select the s etting item with the MENU ▼/▲key, and s et
th e co rrect val u e w ith t he MENU- / + k ey.
5) Pr ess the DI SPLAY ke y tw ice, and r etu rn t o th e n or mal scr ee n.
(5) Receive channel of setting
Refer to th e OPE RATI NG I NST RUCTIONS an d set th e r ece ive cha nn el s
( chan ne ls pr ese t) as descr ibe d
(6) User Setting
Check t he us er s etti n g val u e of Tab le 2, a nd if se tti ng value is dif fer en t, set
th e co rrect val u e.
For setting, refer to the OPE RATI NG INSTRUCTIO NS .
(7) Setting of SERVICE MENU
Ve rif y the set ting it ems of th e SE RVIC E M ENU , and r eset w he re n ecessa r y.
For setting, refer to the SERVICE ADJUSTMENTS.
S
ERVI
C
E MEN
U
1.IF 2.V
/C
3.DEF 4.VSM PRESET
5.PRESET
6.SETUP TOUR OFF
1-6 SELECT DISP : EXIT
******
************
****** *****
**********
***** **
****
**
.
***
******
***
*** ** **
*** ** ***** ** **
*** ** ** ** ***
** ***** ***
** ***
Fig.1
Fig.2
SY STEM CONSTANT- Ⅰ
ⅠⅠ
Ⅰ
COLOUR :
BI LIN G UAL : N O
TUNE R : MU
ECO SENSOR : YES
L ANGU AGE :
SYSTEM CONSTA NT SE T 1
***
***
:
S
ELE
C
T
- / + : OPERATE DISP : EX IT
/
SY STEM CONSTANT- Ⅱ
ⅡⅡ
Ⅱ
B/B SOUND :
LOCK : 180
CO
L
OU
R A
U
T
O
:
QSS : MINT
ALC : NO
TEXT RATE : 20
SYSTEM CONSTA NT SE T 2
***
:SELECT
- / + : OPERATE DISP : EX IT
/
***
SY STEM CONSTANT- Ⅲ
ⅢⅢ
Ⅲ
AMP T UNER : NO
VNR : YES
TEXT TABLE : CYL
VOLUM PWM : POS
SYSTEMCONSTANT SET 3
:SELECT
- / + : OPERATE DISP: EXIT
/
KEY ASSIGNMENT OF REMOTE CONTROL UNIT
MENU
▼/▲key
MENU
－/＋key
DISPLAY
key
PICT URE
MO D E ke y
NUMBERS
key
E xce pt f or d if fer en ce i n bo dy co l our, t he R emote Cont r ol
Unit R M-C3 64G Y a nd R M- C36 4 h ave exa ctly th e sa me
Func tions

No. 52025
A
V-20N
3
A
V-20NMG3
A
V-20NMG3B
11
SE TTING OF SY STEM C ONSTANT SET
Setting value
Setting item Setting contents AV-20N3 AV-20N3/D AV-20NMG3 AV-20NMG3B AV-20NMG3/-A
COLOUR TRIPLE MULTI.
BILINGUAL NO
TUNER MU
AI ECO S ENSOR YE S
LA NG UA GE E/R E/C/ M/I E/R/A /P
B/B SOUND OFF ON
LO CK
YES 10 20 ～230
250 240 18 0
COLOUR AUTO NO YE S
QSS MI NT
ALC NO
TEXT RA TE 10 20 40 80 20
AMP TUNER NO
VNR YE S
TEXT TABLE CYL
VOL UM PW M POS
Table 1
US ER SE TTING V ALUES
Setting item Setting value Setting item Setting value
SUB POWER ON LANGUAGE ENGLISH
CHA NNE L PO SITIO N 1 PO SITIO N CHA NNE L P RE SET Refe r t o OPE R ATING I NS TRU CTION
VOL UME About 10 AI ECO S ENSOR OFF
TV/VIDEO TV VNR OFF
ON SCREEN DI SPL AY POS ITION INDICATIO N AUTO S HUTOFF OFF
COLOUR SYSTEM PAL ON TIMER PR1 0:00
SOUND SYSTEM B / G BLUE BACK OFF
OFF TIMER OFF OSD.Shows 00 CHILD LOCK OFF
PICTURE MODE (VSM) BRIGHT
Table 2
YE S NO
YE S NO
ON OFF
YE S NO
MI NT MQ SS
YE S NO
YE S NO
YE S NO
A
RA CYL
MU MA
MUL T I. PA LTRIPLE
POS NEG
E/R/A /P E
/
RE/C/M/I

No. 52025
A
V-20N3
A
V-20NMG3
A
V-20NMG3B
12
INITIAL SETTING VALUE OF SERVICE MENU
1. Ad justment of the SE RVICE MENU is m ade on the bas is of the initial s etti ng va lues ; howev er, t he new se tting va lues w hi ch
set the screen in its optimum condition may differ from the initial setting.
2. Do no t change the initial Setting Values of the Setting (Adjustment) items not listed In “ADJUSTMENT”.
2. V/C
Initial setting v al ue
Colou r sy st em
Setting item
Va riabl e
range PA L SE C AM NT SC 3.5 8 NT SC 4.4 3
RED
GREEN1. CUT OFF
BL UE
- 128 ～+127 -50
RED
2. DRI VE BL UE - 128 ～+127 + 0
3. BR IG HT -127～+127 + 0
4. CONT . -63 ～+63 + 0
5. COLOUR -63 ～+63 + 0
TV + 0 + 0
AV -2 0N3
AV -2 0N3/D +0 - 2
6. TINT VI DE O AV -2 0N MG 3
AV -2 0N MG 3B
AV -2 0N MG 3/-A
-63 ～+63
+8 - 2
7. SECAM BL ADJ. -31 ～+31 + 0
TV -8(Fixed)
8. SHARP Do No t Ad j.
VI DE O -32～+31 +15
(
Fixed
)
3. DEFLECTION
Initial setting v al ue
Setting item Variable range
fv : 50Hz MODE fv : 60Hz MODE
1. VER. POS ITION -04 ～+03 - 2 - 3
2. HOR. POSITION -16 ～+15 +1 + 4
3. VER. HE IGHT -64 ～+63 -40 + 0
4. VER . L INE AR IT Y -32 ～+31 +13 - 3
5. VER. SWCURVE -32 ～+31 -32 + 0
6. H O R. VC O AD J UST Do Not Adj. -63 ～+62 + 0 + 0
4. VS M PRE SE T
VS M
p
r ese t
VSM mode
Setting item
BRIGHT STANDARD SOFT
TINT SE TTING VA LUE +1 5
COLOUR SE TTING VA LUE +15
BR IG HT SE TTING VA LUE +1 5
CONT . SE TTIN G VA LUE +30 + 15 +11
SHARP SE TTING VA LUE +1 5 +1 2

No. 52025
A
V-20N
3
A
V-20NMG3
A
V-20NMG3B
13
5. PRESE T
The items in the following table, it is no requirem ent for adjustment.
If values had changed by the mi ss operati on, set the initial setting value s i n the fol lowing table.
Colou r Sy st em Do No t Ad just
Initial setting value (Fixed value)
Setting item
PA L SE C AM NT SC 3.5 8 NT SC 4.4 3
1. C TRAP FIX 1 1 1 1
2. SHARP PEAK 0 0 0 0
3. ABL 1 1 1 1
4. GAMMA 0 0 0 0
TV 0 2 2 3
5. Y. DELAY TIME
VI DE O 0 2 0 2
6. BL ACK EX P STA RT ＋3＋3＋3＋3
TV 1 1 0 0
7. C-BPF
VI DE O 1 1 1 1
8. CW / SCP 0 0 0 0
9. VIF DET LEVEL 0 0 0 0
11. IF AGC MIN 0 0 0 0
12 . VIF AGC 0 0 0 0
13. VIF PMOD 0 0 0 0
19 . VNR 15 15 15 15
20 . R GB LIM 1 1 1 1
21. RGB LIMIT LEVEL 2 2 2 2
23. TEXT H. POS ITION -3 -3 -3 -3
24. READ DATA
Sound System D o No t Ad ju s t
Setting item B/G I D/K M
10. SIF DET LEVEL ＋0＋0＋0＋0
14. SIF BPF BW ADJUST ＋0＋0＋0＋0
15. SIF TRAP FO ADJUST ＋0＋0＋0＋0
16. SIF TRAP FO ADJUST 2 ＋0＋0＋0＋0
17. SIF -TRAP 0 0 0 0
18. SIF -BPF 1 0 0 0
22 . SIF S W 0 1 1 1

No. 52025
A
V-20N3
A
V-20NMG3
A
V-20NMG3B
14
REPLACEMENT OF IC301 (IF V/C DECODER)
"For the I C301(IF V/C DECODER) of this model, all data are written in the micr o-c ompute r. So, wri te the data i n the micro-
computer in accordance with the following procedures before starting adjustment.
PROCEDURES
(1) Turn t he POW ER O FF.
(2) R ep lace t he IC30 1 w ith a n ew o ne .
(3) W hi le pr essing ME NU bu tto n a nd VO L+ bu tto n ON the F RO NT CABINE T s imul t ane ous l y, t ur n th e POW ER O N. W h en th e POW ER is
turned ON, th e d at a is writ ten in t he m icro-co mp ute r imm ed iately.
LOCATIONS OF FRONT PANEL BUTTONS AND LAM PS
MENUbuttons
CHANNEL ･/ ･buttons
(ME NU ･/ ･bu tt ons)
VOLUME
－/＋buttons
(MENU －/＋bu tto ns)
AI ECOsensor
REMOTE CONTROL sens or
ON TIMER lamp
POWERlamp
MAIN POW ER but ton
MENUbuttons
CHANNEL －/＋buttons
(ME NU －/＋buttons)
VOLUME
－/＋buttons
(MENU －/＋bu tto ns)
AI ECOsensor
REMOTE CONTROL sens or
ON TIMER lamp
POWERlamp
MAIN POW ER but ton
1
2
3
4
5
6
7
8

No. 52025
A
V-20N
3
A
V-20NMG3
A
V-20NMG3B
15
SERVICE ADJUSTMENTS
BEFORE STARTING SERVICE ADJUSTMENT
1. There ar e 2 w ay of adjus ti ng thi s TV: One i s wi th the
REMOTE CONTROL UNIT and the other is the conventional
method using adjustment parts and components.
2. The adjustment with the REMOTE CONTROL UNIT is made
on the basis of the initial setting v alues. The setting values
which adjust the screen to its optimum condition may differ
from the initia l s etti ng v al ues.
3. M ake s ur e th at conn ect ion is c orrect ly made t o AC p ower
sou rc e.
4. T urn on t he p ower of th e se t an d eq uipm en t bef or e us e, an d
sta rt t he ad ju stm en t pr oc edur e s af ter w aiti n g at l east 30 min ute s.
5. U nless ot her wise spec if i ed, p r ep are th e mo st sui ta bl e r ec epti o n
or i np ut sign al for adjust m ent.
6. N ev er t ouc h a ny adjus tme nt part s, whi ch ar e not sp e cif ied
in t he li st f or thi s adjust me nt VRs , t ra nsf or ms, c onde nser s,
etc.
7. Prep ar atio n f or ad justm en t
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 / BRIG HT
CONT. / SHARP CENTER
BL UE BA CK OFF
OFF TIMER OFF
AI ECO S ENSOR OFF
AUTO SHUT OFF OFF
MEASURING INSTRUMENT AND FIXTURES
1.DC voltmeter (or digital voltmeter)
2.Oscilloscope
3. Sign al g en er at or (P att er n g en er at or) [ PAL / S EC AM / NT S C]
4.Remote control unit
ADJUSTMENT ITEMS
Ad justment item Ad justment item
B1 POWE R SUPPL Y DEFLECTION c ircuit adjustment
FOCUS adjustment VSM PRESET s etting
IF circ uit a djust me nt PUR ITY/ CO NV ER GENCE adjus tm ent
V/C (Video / Chroma) circuit adjustment

No. 52025
A
V-20N3
A
V-20NMG3
A
V-20NMG3B
16
BASIC OPERATION OF SERVICE MENU
"The adjustment using SERVICE MENU
The f ollowing adjus tme nt it ems u se t he SE RV ICE MENU in th e series of the adju stment . The ad ju stment s are m ade on the bas is of the
initi al se tti ng val u es. Th e ad ju stm ent val u es whi ch ad ju st t he scr een to th e o ptim um co ndi t io n c an b e di ffe re nt fr om th e in iti a l sett in g va lues.
W ith th e S ER VIC E ME NU, var ious s ett in gs c an be m ade , a nd the y are br oa dly cl assifie d in th e f ollo win g ite ms of s etti n gs.
1.I F ･･･････ ･････････････ ･･･ Adjustment of the IF circuits.
2.V /C ･･･････ ･････････････ ･･ Ad ju stm en t of th e VIDEO /CH RO MA ci rcuit.
3.DEF ･･･････ ･････････････ ･ Adjustment of the DEFLECTION circ uit.
4.V SM PR ES ET ･･･････ ･････ Ad ju stm en t of th e i nit ia l sett in g va lue s of VSM co nd it i on as ST A NDA RD, SOF T a nd BRIGH T.
(VSM : Video Status Memory)
5.PRESET ･･･････ ･･････････ Adjustment of the RF circ uit [Do not adjust].
6. SETUP TOUR OFF ･･･････ It s hou ld b e able to select m ode (LANGUAG E a nd AUTO CH PRESE T)..
[Shou ld be OFF].
"Key operation of the SERVICE MENU
[Enter to SERVICE MENU]
Press the DI SPLAY key and t he PICTURE MODE key of the REMOTE CONTROL
UNI T si mu lt an eou sl y. Th en ent er th e S ERVIC E ME N U m od e as sh ow n in Fi g.1 .
[Exit from SERVICE MENU]
W hen co m plete th e ad j ust me nt w ork, pr ess th e DI SPLAY key to return t o th e
SERVICE MENU.
An d th en pr ess th e DI SPLAY ke y ag ai n, r etur n to th e n or mal scr een .
[ Se lec t fr om SE R VIC E M E NU ]
In SERVI CE M ENU, press t he n umber (1 ～6) ke y of th e r em o te c ont ro l un it , to se lect
an y of th e ad j ustm en t i te ms.
The col o urs which se le cte d ite m ch ar act ers a r e ch ang ed .
SE RV ICE M ENU
SE RV ICE ME NU
1.IF 2.V/C
3
.DEF 4.V
S
M PRE
S
ET
5.PRESET
6.SETUP TOUR OFF
1-6 SELECT DISP : EXIT
******
************
***********
**********
***** **
****
**
.
***
******
***
*** ** **
*** ** ***** ** **
*** ** **** ***
** ***** ***
** ***
Fig.1
KEY ASSIGNMENT OF REMOTE CONTROL UNIT
MENU
▼/▲key
MENU
－/＋key
DI SP LA Y k e y
PICT URE
MO D E ke y
NUMBERS
key
Exce pt f or di ff er enc e in bod y colo ur , t he Re mo te Contr o l Uni
t
RM-C 36 4G Y an d R M-C3 64 ha ve e xactly t he sam e Fu nctio ns.

No. 52025
A
V-20N
3
A
V-20NMG3
A
V-20NMG3B
17
[Method of setting]
1. IF
[1. VCO]
①1 K ey ･･･････ ･････････････ ･････ Select 1.IF.
②1 K ey ･･･････ ･････････････ ･････ Select 1.VCO
③The VCO (CW) screen will be displayed a allow mark when the AFC voltage is at a certain level.
④DISP LA Y K ey･･･････ ･･･････････ As you press this key twice, you will return to the SE RVICE M E NU.
[2. DELAY POINT]
①1 K ey･･･････ ･････････････ ･････ Select 1.IF.
②2 K ey･･･････ ･････････････ ･････ Se lect 2.DELAY P OINT.
③ME NU - /+ K ey ･･･････ ･･････････ Set (adjust) the setting values of the s ettin g items.
④DISPLAYKey･･･････ ･･･････････ W hen th is is presse d t wice, you will ret ur n t o t he SE RV IC E M ENU.
2.V /C, 3.DEF an d 4 .V SM PRES ET
①2~4Key ･･･････ ･････････････ ･･･ Select one from 2. V/C, 3. DE F an d 4. VSM PRE SET.
②MENU ▼/▲Key ･･･････ ･･･････ Select s etting items.
③MENU-/+ Key ･･･････ ･･････････ Adju st th e va lues of t he i tem s.
④DISP LA Y K ey ･･･････ ･･･････････ W hen th is is presse d, re tur n t o t he SE RVICE MEN U.
6.SE TUP TOUR
①B y p r essing the 6 key, you can ch ang e t he ON or OFF ( should be OFF).
(ShouldbeOFF)
%･If it is ON, th en you tu rn th e T V po we r off , w h en you ar e t ur n t he T V p ower o n a ga in .
The JVC’s logo will be shown about 15 seconds automatically.
②MENU -/+ Key ･･･････ ･･････････ Select Language.
③MENU ▼Key･･･････ ･･････････ Au to Se arch.

No. 52025
A
V-20N3
A
V-20NMG3
A
V-20NMG3B
18
SERVICE MENU FLOW CHART
SE RV ICE M ENU
IF
1. VCO
2. DELAY POINT
1-2 :SELECT DISP: EXIT
SU B M E NU 1. I F
VCO(CW)
***.**
MH z
TOO HIGH
ABOVE REFERENCE
JUS
T REFEREN
C
E
BELOW REFERENCE
TOO LOW
AFT ADJUST
** *(* *)
** *(* *)** *(* *)
** *(* *)
VCO ADJUST
** *(* *)
** *(* *)** *(* *)
** *(* *)
FINE
DISP : EXI T
DELAYPOINT UHF
AGC T AKE- OVER
**
- / + : OPERATE DISP: EXIT
6
.
S
ET
U
P T
OU
R
O
N
/
OFF
(
B
y
p
ressin
g
6- ke
y)
BRIGHT
TINT
COLOUR
BRI
G
HT
CONT.
SHARP
- / + : OPERATE DISP :EXIT
**
**
**
**
**
SUB M E NU 4. V SM PRES ET
/ :SELECT
DEF
- / + : OPERATE DISP :EXIT
***
SU B M E NU 3. D EF
/ :SELECT
50Hz
1. VER. POSITION
PAL
V/C PAL
1.
CU
T
O
FF
- / + : OPERATE DISP :EXIT
(
R
)
* **
(G)
* **
(B)
* **
50Hz
SU B M E NU 2. V /C
/ :SELECT
PRESET
1. C -T RAP FI X
- / + : OPERATE DISP :EXIT
***
50Hz
SUB M E NU 5. P RE SET
/ :SELECT
B/G
PAL
S
ERVI
C
E MEN
U
1.IF 2.V/C
3.DEF 4.VSM PRESET
5.PRESET
6.SETUP TOUR OFF
1-6 SELECT DISP : EXIT
******
************
****** *****
**********
***** **
****
**
.
***
******
***
*** ** **
*** ** ***** ** **
*** ** ** ** ***
** ***** ***
** ***
O
FF

No. 52025
A
V-20N
3
A
V-20NMG3
A
V-20NMG3B
19
ADJUSTMENT LOCATIONS
S
1Pin TP-91(B1)
2Pin NC
3Pin X-ra
y
1
4Pin X-ra
y
2
5Pin TP-E
(
)
HVT
S
1
HV
U
IC301
MEMORY IC
IC702
IC701
F9 01
DEG
TU001
FRONT
TOP
MAIN PWB
CRT SOCKET PWB
(SOLDER SIDE)
TP-47G/R
E1
U
T
PW
UPPER :FOCUS
LOWER:SC REEN
TP-47R/G
TP-47B
TP-E
T
CRT EARTH WIRE
(BRAIDED ASS'Y)

No. 52025
A
V-20N3
A
V-20NMG3
A
V-20NMG3B
20
ADJUSTMENTS
B1 POWER SUPPLY
Item Measuring
instrument Test point Ad justment part Description
Check of
B1 Power
Supply
Signal
generator
DC Vo lt -
meter
TP-91 ( B1)
TP-E (#
##
#)
1. Inp ut a wh ol e bl ack sig na l.
2. C on nect a D C vo lt me ter t o TP- 9 1(B1) a nd TP-E ( #).
3. M ake sur e t hat th e volt ag e i s DC 1 16. 5±2.0 V.
FOCUS ADJUST MENT
Item Measuring
instrument Test point Ad justment part Description
Ad ju st m en t
of FOCUS
Signal
generator
FOCUS VR
[In HVT]
1. Input a cross-hatch signal.
2. W hi le w atchin g th e s cr een, ad ju st the FO CUS V R t o m ake th e
ver ti cal and ho rizo nta l l in es as f in e a nd sha rp as possi b le.
3. M ake sur e th at wh en the scr ee n i s d ar ken ed, the l in es r e ma in i n
g ood focu s.
IF CIRCUIT ADJUSTMENT
Item Measuring
instrument Test point Ad justment part Description
●Please use signal generator which is correct proof about the
sen ding fr eq ue ncy.
Ad ju st m en t
of VCO
(
CW
)
Signal
generator
Remote
control unit
1. VCO
1. Inp ut th e PA L f ull colo ur b ar (2 10 .2 5MHz) si g nal.
2. En ter th e SERVICE ME NU.
3. Se le ct 1 .IF f ro m t he SERV ICE MENU.
4. Press 1 ke y an d s el ect 1. VCO.
5. Select VCO ADJ US T with MENU ▲/▼key.
6. Press MENU -/+ k ey unt il th e co lour of t he c har act er s TOO
HIGH ch an ges b lu e to ye l lo w . Th en g r ad ually pr ess th e MEN U
- /+ key u ntil th e TOO LOW ch ang es ye l low . At this t ime, conf irm
th at t he valu e of VCO ADJUST is n ear + 00 .
7. Select AFT ADJUST with MENU ▲/▼key.
8. Press MENU -/+ key until the characters JUST REFERENCE
ch ang es b l ue to yel low .
9. Press the DI SPLAY key three times to return to normal screen.
VCO (CW)
***.**
MHz
TOO HIGH
AB OVE REFEREN CE
JU ST REF ER ENCE
BELOW R EFEREN CE
TOO LOW
AF T AD JUST
** *(* *)
** *(* *)** *(* *)
** *(* *)
VCO ADJUST
** *(* *)
** *(* *)** *(* *)
** *(* *)
FINE
DISP :EXIT
YE LLOW
D
o
n
ot
adjust
ADJUSTMENT A T T HIS POIN T ISUSELES S
ABOVEREFERENCE
TOO HIGH
B ELO W RE F E RE NC E
JUS
T R EFE RE N
C
E
TOO LOW
ADJUSTMENT POINT