JVC AV-25BT6ENS User manual

No.52056
AV-25BT6ENS
AV-25BT6EN
B
1COPYRIGHT © 2002 VICTOR COMPANY OF JAPAN, LTD.
Jul. 2002
AV25BT6ENS
AV25BT6ENB
CONTENTS
!SPECIFICATIONS ････････････････････････････････
････････････････････････････････････････････････････････････････
･････････････････････････････････････････････････････････････
･･････････････････････････････････････････････････････････
･････････････････････････････ 2
!SAFETY PRECAUTIONS ････････････････････････････････
････････････････････････････････････････････････････････････････
･･･････････････････････････････････････････････････････
･･････････････････････････････････････････････
･･･････････････････････ 4
!FEATURES････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････････････････････････････････････
･･･････････････････････････････････
･･････
･･･ 5
!MAIN DIFFERENCE LIST ････････････････････････････････
････････････････････････････････････････････････････････････････
･･･････････････････････････････････････････････････････
･･････････････････････････････････････････････
･･･････････････････････ 5
!SPECIFIC SERVICE INSTRUCTIONS ････････････････････････････････
････････････････････････････････････････････････････････････････
･････････････････････････････････････････････
･･････････････････････････
･････････････ 6
!SERVICE ADJUSTMENTS ････････････････････････････････
････････････････････････････････････････････････････････････････
･････････････････････････････････････････････････････
･･････････････････････････････････････････
･････････････････････ 10
!PARTS LIST ････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････････････････････････････････････
･････････････････････････････････
･･
･21
★
OPERATING INSTRUCTIONS
★
STANDARD CIRCUIT DIAGRAM ････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････････････････････
････････････････････････････････
････････････････2- 1
SERVICE MANUAL
COLOUR TELEVISION

No. 52056
A
V-25BT6ENS
A
V-25BT6ENB
20
■
■■
■WHITE BALANCE ADJUSTMENT
Item Measuring
instrument Test point Ad justment part Description
WHITE
BALANCE
adjustme nt
(Low light)
Signal
generator
Remote
control unit
WR
WG
WB
1. Receive a bl a ck & wh it e si gn al (colo ur off ).
2. Enter SE RVICE MENU.
3. Select WR / WG / WB wit h the ( / ) key, res pect ively.
4. Adjust WR / WG / WB with t he FUNCTION ( / ) key ,
resp ectively, unt il th e whit e p art tu rn s to pur e whit e wit hout a ny
other color..
WHITE
BALANCE
adjustme nt
(High light)
Signal
generator
Remote
control unit
BR
BG
1. Receive a bl a ck & wh it e si gn al (colo ur off )
2. En ter SE RVICE M ENU.
3. Select BR / BG with th e FUNCTION ( / ) key respect ively.
4. Adjust BR / BG with the FUNCTION ( / ) key respectively
until the white part of screen make white colour.
It em WR WG W B
Recom mended value 03 0 03 0 03 0
It em BR BG
Recom mended value 02 8 02 9

1
No.52056
AV-25BT6ENS
AV-25BT6ENB
AV-25BT6ENS
AV-25BT6ENB
Jul. 2002 No. 52056
2-24
STANDARD CIRCUIT DIAGRAM
NOTE ON USING CIRCUIT DIAGRAMS
1.SAFETY
The components identified by the symbol and shading are
critical for safety. For continued safety replace safety critical
components only with manufactures recommended parts.
2.SPECIFIED VOLTAGE AND WAVEFORM VALUES
The voltage and waveform values have been measured under the
following conditions.
(1)Input signal : Colour bar signal
(2)Setting positions of
each knob/button and
variable resistor
(3)Internal resistance of tester :DC 20k /V
(4)Oscilloscope sweeping time :H 20µS/div
:V 5mS/div
:Others Sweeping time is
specified
(5)Voltage values :All DC voltage values
Since the voltage values of signal circuit vary to some extent
according to adjustments, use them as reference values.
3.INDICATIONS ON THE CIRCUIT DIAGRAM
(1)Resistors
Resistance value
No unit :[ ]
K:[K ]
M
Type
No indication :Carbon resistor
OMR :Oxide metal film resistor
MFR :Metal film resistor
MPR :Metal plate resistor
UNFR :Uninflammable resistor
FR :Fusible resistor
Composition resistor 1/2 [W] is specified as 1/2S or Comp.
(2)Capacitors
: Original setting position
when shipped
4.NOTE FOR REPAIRING SERVICE
This model's power circuit is partly different in the GND. The
difference of the GND is shown by the LIVE side GND and the
ISOLATED(NEUTRAL) side GND.Therefore, care must be
taken for the following points.
(1)Do not touch the LIVE side GND or the LIVE side GND and the
ISOLATED(NEUTRAL) side GND simultaneously. If the above
caution is not respected, an electric shock may be caused.
Therefore, make sure that the power cord is surely removed from
the receptacle when, for example, the chassis is pulled out.
(2)Do not short between the LIVE side GND and ISOLATED(NEUTRAL)
side GND or never measure with a measuring apparatus measure
with a measuring apparatus ( oscilloscope, etc.) the LIVE side GND
and ISOLATED(NEUTRAL) side GND at the same time.
Ifthe aboveprecaution isnot respected ,a fuse or any parts will be broken.
Since the circuit diagram is a standard one, the circuit and
circuit constants may be subject to change for improvement
without any notice.
NOTE
Due improvement in performance, some part numbers show
in the circuit diagram may not agree with those indicated in
the part list.
When ordering parts, please use the numbers that appear
in the Parts List.
Type
MM :Metalized mylar capacitor
PP :Polypropylene capacitor
MPP :Metalized polypropylene capacitor
MF :Metalized film capacitor
TF :Thin film capacitor
BP :Bipolar electrolytic capacitor
TAN :Tantalum capacitor
(3)Coils
No unit :[ µH]
Others :As specified
:[M ]
Capacitance value
1 or higher :[pF]
less than 1 :[µF]
Withstand voltage
No indication :DC50[V]
Others :DC withstand voltage [V]
AC indicated :AC withstand voltage[V]
Electrolytic Capacitors
47/50[Example]:Capacitance value [µF]/withstand voltage[V]
No indication :Ceramic capacitor
AV-25BT6ENS, AV-25BT6ENB
VP0207
DP6060
TOP
FRONT CONTROL PWB PATTERN

No.52056No.52056
2
AV-25BT6ENS
AV-25BT6ENB
AV-25BT6ENS
AV-25BT6ENB
2-2
CONTENTS
SEMICONDUCTOR SHAPES
2-2
BLOCK DIAGRAM 2-3
CIRCUIT DIAGRAMS 2-5
2-17
2-19
2-20
PATTERN DIAGRAMS
MAIN PWB CIRCUIT DIAGRAM
HEADPHONE PWB CIRCUIT DIAGRAM
FRONT CONTROL PWB CIRCUIT DIAGRAM
CRT SOCKET PWB CIRCUIT DIAGRAM
SEMICONDUCTOR SHAPES
TRANSISTOR
BOTTOMVIEW FRONT VIEW TOP VIEW
CHIP TR
IC
BOTTOMVIEW FRONTVIEW TOPVIEW
CHIP IC
TOP VIEW
1 N
N
1
OUT
E
IN
IN OUTE
1 N
N
1
N
N
N
1
N
E
C
B
ECB
C
BE
BCE
(G)(D)(S)
ECB
ECB
2-21
2-23
2-23
MAIN PWB PATTERN
HEADPHONE PWB PATTERN
CRT SOCKET PWB PATTERN
2-24
FRONT CONTROL PWB PATTERN
HEADPHONE PWB PATTERN
FRONT
2-23
CRT SOCKET PWB PATTERN
TOP

No.52056 No.52056
3
AV-25BT6ENS
AV-25BT6ENB
AV-25BT6ENS
AV-25BT6ENB
2-3 2-4
BLOCK DIAGRAM
CRT
PLL/VST TUNER
UV1315/16
VIDEO
PROCESSOR
STV2248C
+150 B+
CONTROLLER
ST92195
I2C
SERVICE
CONNECTOR
EEPROM
KEYPAD
IR
SENSOR
STEREO SOUND
MSP34X0D/G
VIRTUAL DOLBY
QSS
HPAMP
TDA1308
AUDIO AMP
TDA7269A
L
R
SMPS
MC44608
+14V
-14V
+8V
+5V
VIDEO
SWITCHING
CIRCUITS
IF
SCART1
SCART2
SVHS FAV/BAV
HOR DRIVE
BU2508
VER AMP
STV9306
RGBAMP
TDA6108
FBT
VER. DEFL.
HOR. DEFL.
L
R
MONO
+5V STBY
SUB AMP
TDA7261 SUBW
MSP 3411G

No.52056 No.52056
4
AV-25BT6ENS
AV-25BT6ENB
AV-25BT6ENS
AV-25BT6ENB
2-5 2-6
CIRCUIT DIAGRAMS MAIN PWB CIRCUIT DIAGRAM [1/6]
0V 0V 0V 0V
4.9V 4.9V 3.9V 4V
4.8V
4.9V
1.6V
1.4V
0V
1.6V
4.9V
3.9V
1.9V
1.8V
4.9V
1.4V
1.4V
0.2V
4.9V
0V
0V
0V
0V
0V
0V
1.6V
1.8V
4.9V
0.9V
4.5V
0V
1.6V
1.6V
0V
1.5V
0V
0V
4.9V
0.2V
0.2V
0V
4.9V
3.6V
0.1V
1.6V
0.2V
1.6V
1.6V
4.5V
4.9V
4.9V
0V
4.6V 0V
4.9V
4.9V
4.2V
2.8V
0.1V
2.5V 5.5V 0V 3.9V 3.5V 4.9V 4.9V 0V 23.3V 0V 0V
IC501 40
IC501 41
6
5
MAIN PWB (1/6)
VE-20101572 (AV-25BT6ENS, AV-25BT6ENB)

No.52056 No.52056
5
AV-25BT6ENS
AV-25BT6ENB
AV-25BT6ENS
AV-25BT6ENB
2-7 2-8
MAIN PWB CIRCUIT DIAGRAM [2/6]
0V
-15.6V 15.3V 0V 12.1V
-15.6V
0V 0V 0V 0V
15.1V
12.1V
14.9V
0V
0V
12.1V
7.8V 2.2V
2.8V
2.4V
2.4V
2.3V
3V
2.5V
2.4V
2.4V
2.2V
1.9V
0V
3.8V
1.1V
3V
0V
4.8V
4V
3.9V
4V
0.9V
0.8V
5.5V
5.7V
4.4V
2.9V
2.3V
3.8V
3.8V
7.9V
3.5V
0.1V
3.1V
2.5V
3.1V
7.9V
4V
0V
3.9V
2.3V
4.1V
0V
4.1V
1.6V
3.8V
2.4V
1.7V
2.4V
0V
0.1V
4.3V
2.5V
2.5V
2.5V
4.3V
IC403 32 IC403 31 IC403 30
3.5 44
IC403 48
IC403 47
2
6
MAIN PWB (2/6)
VE-20101572
(AV-25BT6ENS, AV-25BT6ENB)

No.52056 No.52056
6
AV-25BT6ENS
AV-25BT6ENB
AV-25BT6ENS
AV-25BT6ENB
2-9 2-10
MAIN PWB CIRCUIT DIAGRAM [3/6]
4.9V
4V
4.8V
7.9V
3.3V 2.2V
7.9V
0.1V
0V
7.9V
0.1V
0V
MAIN PWB (3/6)
VE-20101572 (AV-25BT6ENS, AV-25BT6ENB)

No.52056 No.52056
7
AV-25BT6ENS
AV-25BT6ENB
AV-25BT6ENS
AV-25BT6ENB
2-11 2-12
MAIN PWB CIRCUIT DIAGRAM [4/6]
3.9V 3.4V 3.9V 3.3V 5.5V 26.3V 1.4V 0V 12.6V 26.9V 1.2V 12.6V 3.1V 12.6V 4.3V
0V
5.5V
5.5V
193V
0V
0V
0V 11.8V
14.7V
-0.1V 0V
0V
5.8V
3.6V
13.6V
7.4V
6.8V
IC601 2
3
IC601 5
30
IC601 6
2
IC601 7
60
Q601 B
2
TR601 4
300
TR601 5
250
TR601 6
120
TR601 8
25
TR601 9
65
1300
-0.1V
MAIN PWB (4/6)
VE-20101572 (AV-25BT6ENS, AV-25BT6ENB)

No.52056 No.52056
8
AV-25BT6ENS
AV-25BT6ENB
AV-25BT6ENS
AV-25BT6ENB
2-13 2-14
MAIN PWB CIRCUIT DIAGRAM [5/6]
1.1V
0.1V
4.9V
107.5V
12.5V
2.5V
281V
2.5V 0V
12.5V
4.9V
12.2V
11.1V
0V
0.6V
0V
0.1V
2.3V
12.2V 4.9V
9.4V 4.9V
12.2V 7.9V
MAIN PWB (5/6)
VE-20101572 (AV-25BT6ENS, AV-25BT6ENB)

No.52056 No.52056
9
AV-25BT6ENS
AV-25BT6ENB
AV-25BT6ENS
AV-25BT6ENB
2-15 2-16
MAIN PWB CIRCUIT DIAGRAM [6/6]
1.4V 3.7V3.7V
2.5V3.7V
0V4.9V
1.4V1.4V
1.4V
0V
2.4V
2.4V
4V3.2V
0.1V
4.9V
0V
0V
0V 1.6V
1.6V1.7V2.3V 1.5V
3.7V3.7V
0V3.7V3.7V
0V
3.7V3.7V
0V
0.1V
0.1V
0.1V
0V4.9V
3.7V
3.7V
0V
3.7V
3.7V
6.1V7.9V
6.8V
0V
3.6V
0.1V
0.1V
0.1V
0.1V
0.1V
0V
2V2V4.8V0V
4.9V 4.8V
4.2V
MAIN PWB (6/6)
VE-20101572
(AV-25BT6ENS, AV-25BT6ENB)

No.52056 No.52056
10
AV-25BT6ENS
AV-25BT6ENB
AV-25BT6ENS
AV-25BT6ENB
CRT SOCKET PWB CIRCUIT DIAGRAM
2-17 2-18
CRT SOCKET
PL902
3.8V
0V
2.5V 2.5V 2.5V 0V 4.8V 201V 132V 145V 133V
-0.9V
195V
IC900 7 IC900 8 IC900 9
150 140 160
CRT SOCKET PWB
(AV-28BT8ENS, AV-28BT8ENB)
(AV-28BT8EPS, AV-28BT8EPB)
(AV-28BT8EES, AV-28BT8EEB)
VE-20094670

No.52056 No.52056
11
AV-25BT6ENS
AV-25BT6ENB
AV-25BT6ENS
AV-25BT6ENB
FRONT CONTROL PWB CIRCUIT DIAGRAM
HEADPHONE PWB CIRCUIT DIAGRAM
2-19 2-20
HEADPHONE PWB
(AV-25BT6ENS, AV-25BT6ENB)
VE-20079493
FRONT CONTROL PWB
(AV-25BT6ENS, AV-25BT6ENB)
VE-20083646

No.52056 No.52056
12
AV-25BT6ENS
AV-25BT6ENB
AV-25BT6ENS
AV-25BT6ENB
PATTERN DIAGRAMS MAIN PWB PATTERN
2-21 2-22
FRONT

No.52056
A
V-25BT6ENS
A
V-25BT6ENB
2
SPECIFICATIONS
Content
ITEM AV -2 5BT 6EN S (S ilve r)
AV -2 5BT 6EN B ( Bla ck )
Dimensions ( WxHxD) 69 cm x 54 cm x 47 cm
Weight 27 kg
TV RF System B/G
TV Mode PA L
Colour Sy st em Video Mode PAL / NTSC 3.58 / NTSC 4.43
Teletext System Fast ext / Toptext
St ere o Sy st em German + NICAM
Tuning System Fr equ enc y Synt hes iz er T un in g S ystem
Nu mb er Of CH me mory position 10 0 ch
VHF (VL) 46 .25 MHZ ~ 1 68. 25 MHz
VHF (VH) 17 5.2 5M Hz ~ 46 3.2 5M Hz
UHF 47 1.2 5M Hz ~ 86 3.2 5M Hz
Receiving Frequency
CATV S01- S 4 1 & S7 5- S79
VIF Carrier 38 .9 MHz
32.4 MHz (6.5MHz)
32.9 MHz (6.0MHz)
Intermediate Frequency SIF Carrier
33.4 MHz (5.5MHz)
Colour Sub Carrier Frequency PAL (4.43MHz), SECAM (4.43MHz), NTSC (3.58MHz/4.43MHz)
Aerial Input Terminal 75 Ohm U n bala nced
Power Input AC 2 20V ~ 24 0V, 50Hz
Power Consumption 135W(Max.) 1.8W (stand by)
Pictur e Tube Vi si ble si ze : 59cm ( Measu red d iago na lly)
Hi g h Volt ag e 30 .45kV
Spe ake r 5.7 X 16 cm Oval type X 2
Au dio Output 10W + 10W
Vide o 1V p- p, 75 Ohm
S/V ideo Y: 1Vp - p P ositive
C: 0. 28 6Vp -p
Input
Au dio
(
L/R
)
50 0 mV r ms, H igh I mp eda nce
Vide o 1 Vp-p, 75 O hm
Output Au dio
(
L/R
)
50 0 mV r ms, L ow Imp ed anc e
AV 1 ( Vid eo/A ud i o/R GB)
Rear Side AV 2 (Vid eo/A udio/S- VHS)Input Terminal
Front Side AV 3 ( Vid eo/A ud i o)
Front Side Hea dph on e jac k (S ter e o m ini j ack 3.5∅)
AV1 (V ideo /Au dio)Output Ter minal
Rear Side AV2 ( V ideo /Au di o) ( S electe d TV, AV 1 o r AV3 )
Remote Control Unit VE -3 00 177 63 (RM- C11 00) , Ba tte r y size :AA /R06 dr y b att er y x 2
Design & sp eci ficatio ns ar e su bje ct to cha nge wi thout no tice.

No.52056
A
V-25BT6ENS
A
V-25BT6ENB
3
■
■■
■21-pin Euro connector (SCART socket) : AV1 / AV 2
(P-P= Peak to Peak, S-W= Sync tip to white peak, B-W= Blanking to white peak)
Pin
No . Signal Designation Matching Value AV-1 AV-2
1 AU DIO R o ut put 50 0m Vrms( Nomina l),L ow impe dan ce ○
(TV OUT)
○
(TV/LINE OUT)
2 AUDIO R input 500mVrms(Nominal),High impedance ○○
3 AU DIO L o utp ut 50 0m Vrms( Nomina l),L ow impe dan ce ○
(TV OUT)
○
(TV/LINE OUT)
4 AUDIO G ND ○○
5 GND (B) ○○
6 AUDIO L input 500mVrms(Nominal), High impedance ○○
7Binput 70 0m VB-W, 7 5Ω○ NC
8FUNCTON SW
(SLOW SW) Low : 0-3V, High : 8-12V, High impedance ○NC
9 GND (G) ○○
10 - NC -
11 G in put 70 0m VB-W, 7 5Ω○ NC
12 -NC -
13 GND (R) ○○
14 GND (YS) ○NC
15 R / C input R : 700mVB-W, 75Ω
C : 300mVP-P , 75Ω
○
(R/C)
○
(only C)
16 Ys i n put L ow : 0 – 0. 4, H ig h : 1 - 3 V, 75 Ω○NC
17 GND(VIDEO output) ○○
18 GND(VIDEO input) ○○
19 VIDEO ou tpu t 1V S-W (Negative going sync), 75Ω○
(TV)
○
(TV/LINE OUT)
20 VIDEO / Y input 1VS-W (Negative going sync), 75Ω○○
21 COMMON G ND ○○
[Pin assignment]

No.52056
A
V-25BT6ENS
A
V-25BT6ENB
4
SAFETY PRECAUTIONS
1. The d esi gn of th is pr od uct con ta in s sp ecial har d wa re , ma ny
circuits and components specially for saf ety 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 esi gn un less a uth or ized i n writi n g by th e ma nu fact ur er.
Rep lacemen t p ar ts m ust b e id ent ic al to thos e u sed in th e or igi n al
ci rcu it s. Se r vic e sh ou l d be pe rf or me d b y q ua lifi e d per so nn el
on ly.
2. Al te r ation s of t he desi g n or ci rcui tr y of t he pr od ucts sh ould not be
made. Any design alterations or additions will void the
m anu fact urer 's warr a nt y and w ill f ur th er r elieve t he ma nu factu r er
of r esp onsi b ili ty for per so na l injur y or p r op er ty d am ag e r esul t in g
th er efr om .
3. M an y e l ectr ical an d m ech anica l p ar ts in th e pr od ucts ha ve
special safety-related characteristics. T hese characteristics are
oft en no t e vi den t f r om visua l insp ecti on n or ca n t he pr o tect io n
aff orde d by th em nece ssarily b e ob tai n ed b y u sin g r ep lacemen t
com po ne nts ra ted f or hi g he r vo ltag e, w att ag e, etc. R ep lacem en t
p arts wh ic h ha ve th ese sp ecial s afet y ch ar act erist 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 schematic s and by (!
!!
!) on the parts list in Service
manual. The us e of a sub sti tu te r ep la cem en t which do es n ot
h ave th e same saf ety ch ar act erist ics as t he r eco mmen de d
r eplac em ent par t sh ow n i n th e p ar ts list 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 ATED
(NEUTRAL) side ground or EARTH side ground when
repairing.
Some model's power circuit is partly different in the GND. The
diff erenc e of the GN D i s sh ow n b y th e LI VE si de G ND, th e
ISO LATE D(NEUTRAL) sid e GND a nd EA RTH si de GN D. D on' t
sh ort b etw ee n the L IVE si de GND a nd IS OLATE D( NEUTR AL)
side GND or EA RTH side GND an d ne ver meas ure with a
m easu r in g app ar atu s ( osc il losc ope et c.) th e LIV E sid e GND an d
ISOLATED(NEUTRAL) side GND or EARTH side GND at the
same 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 ti ng shou l d b e ch ecke d or adju ste d ( Se e
ADJU STM ENT OF B 1 POW E R SUPPL Y).
6. The hi gh volta ge app li e d t o th e pi ctu r e tu be mu st con for m wit h
th at sp eci fi ed in S ervice m an ual. E xcessi ve h i gh vo lt ag e ca n
cau se an incr e ase in X- Ray em ission , arci 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 ever e arc in g occurs, remove t he AC power
imm ed iate l y an d de ter mi ne th e ca use b y visua l insp ect io n
( in cor rect in stal lat ion, cracke d or m elte d high vo lt age har n ess,
p oor so ld er ing, et c.) . To m aint ain the p r ope r min imu m l e vel of
sof t X- Ray em ission, c omp on en ts in th e high vol tag e circuitr 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 ompl et e
pr od uct.
7. Do n ot c hec k high volt ag e b y drawing an ar c. Use a high volt age
m eter or a hi g h v oltag e pr ob e wit h a V TVM . Discha rg e th e
picture tube before attempting meter connection, by connecting
a cli p 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 vice i s r equ ir e d, ob serve th e or igi na l lea d dr ess. E xtr a
pr ec aut ion sh ou ld b e g ive n t o assure correct l ea d dr ess in th e
hig h vol tag e cir cui 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 i ndica te evide nce of ove rhea ti ng sho uld
b e r e place d. A l wa ys u se th e ma nuf act urer 's r ep lacem en t
components.
9. Isolation Check
(Safety for Electrical Shock Hazard)
Af ter re-ass emb lin g th e p r odu ct, al ways 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 ermin als, Con tr ol kn obs,
metal cabinet, screwheads, earphone jack , control shafts, etc.)
to be su re th e p r odu ct is 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 l ati on be tw een the A C pr im a ry ci rcu i t an d al l me tal p ar ts
exp ose d t o th e us er, p ar ticularly an y e xp os ed met al p art h avi ng a
r etu rn p ath to t he chass is sho uld wi ths 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 pl ian ce r at ed
200V or more, for a periodof one second.)
This method of test requires a t est equipment not generally found
in t he servic 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 ormer du r in g thi s ch eck.) . U sin g a " Lea kag e
Current Teste r", me asur e th e l ea kag e cu rr e nt f rom each exp osed
m etal p ar t of the ca bi ne t, p art icu lar ly any e xpos ed me tal p ar t
h aving a re turn pa th to t he chassis , t o a kn own go od ea rt h
gr ou nd (wa ter pip e, e tc.) . An y leaka ge curren 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 rn ate 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 mer dur ing t hi s che ck.) . Use an AC vo lt me ter
h avi ng 1 00 0 oh ms pe r vol t or more sens it ivi ty in th e fo ll owi ng
m ann er. Con nec t a 1 50 0Ω10W res ist or par a lle 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 pipe , etc.) . M eas ure th e A C vo lt ag e
acr oss th e r es ist or w ith th e AC vo ltm eter . M ove th e r esistor
con nec ti on to e ach exp ose d me tal par t, p art icul arly a ny exp osed
m etal p ar t havi n g a r etu rn pat h to t he ch assis, an d m easu r e th e
AC voltag e ac ro ss the r es ist or . N o w, re ver se th e plu g i n th e AC
ou tl et and r e pe at eac h m ea sur em en t. An y vol t ag e me asu re d
must not e xc eed 0.75V AC (r.m.s.). This c orre sponds to 0 .5mA
AC (r.m.s.).
However, in tropical area, this mu st n ot exce ed 0.3V AC ( r.m.s.).
This corresponds to 0.2mA AC (r.m.s.).
0.15μF AC-T YP E
1500 Ω10W
GOODEARTH GROUND
PLACE THIS PROBE
ON E A CH EX PO SE D
ME T AL PA R T
ACVOLTMETER
(HAVING 1000 Ω/V,
OR MOR E SENSITIVITY)

No.52056
A
V-25BT6ENS
A
V-25BT6ENB
5
FEATURES
1. It is a remote controlled color television.
2. 10 0 pr og r ams fr om VH F, UHF b an ds or cab le cha nn el s can be
pres et.
3. It c an tun e c able cha nn el s.
4. Cont ro llin g th e T V i s ver y easy by i ts m en u dr ive n s yst em .
5. It h as tw o Eu r ocon n ector s ockets fo r exte r nal de vice ( such as
vi de o r eco rd er, vid eo ga mes , a udi o set, e tc.)
6. Fr ont AV Inp ut avail a ble.
7. St ereo s ou nd s ys tems (German + Nic am) are a vailab le.
8. Full fu nctio n Tele text (Fast ext, Top text ).
9. It is possib le to con nec t h ead ph on e.
10. Direct channel acc ess.
11 . AP S ( Aut om at ic P r ogr amming Syste m) .
12 . Al l pr og rams ca n b e nam ed .
13 . Forwar d o r bac kw ard au to ma ti c tu ning .
14 . Au tom at ic sou nd mu te wh en no tr an smission .
15 . 5 minu tes aft er the br o adc asti ng ( closed own), the TV s wi tch es
itsel f aut om ati ca ll y t o st and -by m od e.
16. Child Lock.
MAIN DIFFERENCE LIST
!
!!
!MODEL No.
Parts Name
AV -2 5B T 6 ENS
(Silver)
AV -2 5B T 6 ENB
( Bl ack )
!POW E R BUTTO N VE -2 00 435 32 VE -2 00 009 03
!FR ON T CA BINET VE -2 00 464 46 VE -2 00 041 31
!FU NCTION B UTTO N VE -2 00 435 45 VE -2 00 037 30
!REAR COVE R VE -2 00 925 23 VE -2 01 015 75
CARTON BOX VE -5 00 284 94 VE -5 00 285 07
!RATIN G L ABE L VE -2 01 021 34 VE -2 01 021 64

No.52056
A
V-25BT6ENS
A
V-25BT6ENB
6
SPECIFIC SERVICE INSTRUCTIONS
DISASSEMBLY PROCEDURE
REMOVING T HE REAR COVER
1. R emove th e 8screws marked A.
2. R emove th e 2screws marked B.
3. W i thdr a w t he r ear co ver to wa rd you .
REMOVING T HE MAIN PWB ASS’Y
"After removing the rear cover .
1. You c an pull o ut t he MA IN PW B ASS’Y.
REMOVING T HE HEADPHONE PWB ASS’Y
"After removing the rear cover.
1. R emove th e 1screw marked C.
2. Rem ove th e H EA DP HO NE PW B AS S’Y & BRACK ET.
REMOVING T HE SPEAKER
"After removing the rear cover.
1. Remove th e 4screws marked D.
2. Remove th e SP EAK ER.
REMOVING T HE FRONT CONTROL PWB
"After removing the rear cover.
"Rem ove th e M AIN PW B AS S’Y.
1. Remove the 4screws marked E a nd r em ove th e FR ON T
CONTROL PWB.
REMOVING T HE POWER SW
"After removing the rear cover .
"Rem ove th e M AIN PW B AS S’Y.
"Remove the 2screws marked F, and remove th e POW ER SW.
REAR COVER
BRACKET
S
PEAKER
FR
O
NT
CO
NTR
O
L PWB
MAIN PWB
C
E
HEADPHONE
PWB
D
C
RT
FRONT CABINET
POW ER S W
F
A
AV
TERMINAL
BOARD
B

No. 52056
A
V-25BT6ENS
A
V-25BT6ENB
7
REPLACEMENT OF CHIP COMPONENT
!CAUTIONS
1. Avoid heating for more than 3 seconds.
2. Do n ot ru b t he elect ro des an d t he r esist p ar ts of th e p att er n.
3. W hen r emoving a c hi p par t, m elt th e s older ad equ ate l y.
4. Do n ot r euse a ch i p p ar t afte r re mo ving it .
!SOLDERING IRON
1. Use a hig h ins ulatio n s older ing iron with a t hin po inted e nd of it .
2. A 3 0 w s older ing i ron is r ec om m end ed for easil y r emoving p ar ts.
!REPLACEMENT STEPS
1. How to remove Chip parts
#Resi st ors, ca pa cit ors , et c .
( 1) As sho wn i n th e fi gure, p ush th e pa rt with tw ee zer s a nd
alte rn at el y m elt th e sol de r at each en d.
( 2) Sh if t w ith tw eeze rs an d r em o ve th e ch ip p ar t.
#Tran s ist ors, d iod es , va ria bl e r es ist or s, et c.
( 1) Ap pl y e xt ra so ld er to ea ch le ad .
( 2) As sho wn i n th e fi gure, p ush th e pa rt with tw ee zer s a nd
alte rn at el y m elt the sold er at e ach l e ad . Shift and r emove
th e ch ip p art .
Note : After removing the part, remove remaining solder from
the pattern.
2. How to install Chip parts
#Resi st ors, ca pa cit ors , et c .
(1) Apply solder to th e p att ern a s indic ated in the fig ure.
( 2) Gr asp th e ch i p p art w it h t w eez ers and p lace it on th e
sol d er. Th en h eat and me lt th e so ld er at b oth e nds of the
chip part.
#Tran s ist ors, d iod es , va ria bl e r es ist or s, et c.
(1) Apply solder to th e p att ern a s indic ated in the fig ure.
( 2) Gr asp th e ch i p p art w it h t w eez ers and p lace it on th e
solder.
(3) First s older lead Aas indicated in t he figure.
( 4) The n so ld er le ads Band C.
SOLDE R SOLD E R
A
B
C
A
B
C