JVC AV-25P8PH User manual

AV-25P8
No. 56070 1
MODEL NO.
XXXXX XXXXXXX
XXXXXXX XXXXX
XXXXXX
XXXXX
XXX XXXXX XXXXX
XXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXX
SERIALNo.
XXXXXX–XXX
XXXX XX XXXX
XXX XX XXXX
Identify model name
Basic model name
BASIC CHASSIS
JK
SERVICE MANUAL
COLOUR TELEVISION
AV-25P8(PH)
COPYRIGHT  2000 VICTOR COMPANY OF JAPAN, LTD. No. 56070
Sep. 2000
HOW TO IDENTIFY MODEL
While referring to the illustration given below, identify model name on the rating label affixed to the rear cover.
This service manual mainly consists of the following items:
• The items which differ from those for the AV-25PX service manual.
• The initial value for each setting item.
For details other than those described in this manual, please refer to the following service manual.
Reference Service Manual: AV-25PX Service Manual (No. 51752, Aug. 2000)
Note: The page in parentheses shows the one for the AV-25PX service manual (No. 51752, Aug. 2000).
AV-25P8
AV-25P8-PH
AV-25P8

AV-25P8
No. 560702
AV-25PX AV-25P8(PH)
!!
!!
!REF. NO. PART NAME DESCRIPTION
PART No. PART No.
■EXPLODED VIEW PARTS LIST (Pages 35 and 36)
!10 QMP40D0-200J3 QMPR010-200-E2 POWER CORD
or QMP40D0-200J5 or QMPR010-200-K2
!12 LC10477-003A-H LC10477-003A-HK REAR COVER
!14 LC20377-010B-H GG20003-008A-H RATING LABEL
25 LC10475-013A-H LC10475-013A-HK FRONT CABI ASSY
■PRINTED WIRING BOARD PARTS LIST [POWER & DEF PWB ASSY] (Page 41-)
— SJK-2004A-H2 SJK-2013A-H2 POWER & DEF PWBASSY
■PACKING PARTS LIST (Page 47)
1 LC10845-003A-H GG10077-001A PACKING CASE
2 LC10479-002D-H LC10545-004B CUSHION ASSY 8 pcs. in 1 set
!6 LCT0864-001A-H LCT0852-001A-H INST BOOK
7 CM47385-00B-H CP30902-050(R) POS/SERIAL LABEL
!8 LCT0662-001A-H DIGEST MANUAL
!9 LCT0661-001A-H DIGEST MANUAL
PARTS DIFFERENCE TABLE
The different parts between AV-25PX and AV-25P8(PH) are described below:

AV-25P8
No. 56070 3
Item CONTENTS
Dimensions (W ×H ×D) 655mm ×530.5mm ×465mm
Mass 36kg
TV RF System B, G, I, D, K, K1, M
Colour System PAL, SECAM, NTSC3.58, NTSC4.43
Receiving Frequency VHF (L) 46.25MHz ~ 168.25MHz
VHF (H) 175.25MHz ~ 463.25MHz
UHF 471.25MHz ~ 863.25MHz
CATV Mid (X-Z, S1-S10), Super (S11-S20), Hyper (S21-S41) bands receivable
Intermediate Frequency
VIF Carrier 38.0MHz
SIF Carrier 33.5MHz(4.5MHz), 32.5MHz(5.5MHz), 32.0MHz(6.0MHz), 31.5MHz(6.5MHz)
Colour Sub Carrier Frequency
PAL 4.43MHz
SECAM 4.40625MHz, 4.25MHz
NTSC 3.58MHz / 4.43MHz
Power Input Rating: AC110 ~ 240V, 50/60Hz Operating: AC90 ~ 260V, 50/60Hz
Power Consumption 119W
Picture Tube Visible size : 60cm measured diagonally
High Voltage 31.0kV ±1.5kV (at zero beam current)
Speaker & Audio Output Open dome speaker
10W+10W, 10cm round x 2
Video Audio Input terminals
Video1 S-Video Y: 1Vp-p Positive (Negative sync provided, when terminated with 75Ω)
C: 0.286Vp-p (Burst signal, when terminated with 75Ω)
Video 1Vp-p 75Ω(RCA pin jack)
Audio (L/R) 500mVrms (−4dBs), High impedance (RCA pin jack)
Video2 Video 1Vp-p 75Ω(RCA pin jack)
Audio (L/R) 500mVrms (–4dBs), High impedance (RCA pin jack)
Video3 Video/Y Composite video 1Vp-p 75Ω(RCA pin jack)
Component video 1Vp-p 75Ω(RCA pin jack)
Cb Component video B-Y 0.7Vp-p 75Ω(RCA pin jack)
Cr Component video R-Y 0.7Vp-p 75Ω(RCA pin jack)
Audio (L/R) 500mVrms (–4dBs), High impedance (RCA pin jack)
Video4 Video 1Vp-p 75Ω(RCA pin jack)
Audio (L/R) 500mVrms (−4dBs), High impedance (RCA pin jack)
Video Audio Output terminal
Video 1Vp-p 75Ω(RCA pin jack)
Audio (L/R) 500mVrms (−4dBs), High impedance (RCA pin jack)
Aerial Input Terminal 75ΩUnbalanced, Coaxial
Headphone Jack Stereo mini jack (3.5ø)
AV Compu Link terminal AV Compu Link II, mini jack (3.5ø)
Remote Control Unit RM-C113 (AA/R06 / UM-3 dry battery ×2)
Design & specifications are subject to change without notice.
SPECIFICATIONS(Page 2)

AV-25P8
No. 560704
SETTING OF SYSTEM CONSTANT SET (Page 9)
Table 1
SPECIFIC SERVICE INSTRUCTIONS
CONTENTS VARIABLE RANGE INITIAL SETTING VALUE
COLOUR MULTI
MSP NO
SUPER BASS NO
CENTER SPEAKER NO
TEXT NO
BLUE BACK MUTE NO
VOLUME LIMIT YES
COLOUR AUTO NO
TILT YES
C-TRAP 1
E.M.C. NO
N/S WHITE BACK NO
7 LED SPEED 00
MULTI TRIPLE PAL
YES NO
YES NO
YES NO
YES NO
YES NO
YES NO
YES NO
YES NO
1 0
YES NO
YES NO
00 10 20 ... 1250
1270 1260
USER SETTING CONDITIONS (Page 9)
Table 2
PICTURE SETTING FEATURES
PICTURE MODE BRIGHT SLEEP TIMER OFF
CONTRAST CENTER ON TIMER PR1 0:00
BRIGHT CENTER BLUE BACK ON
SHARP CENTER CHILD LOCK OFF
COLOUR CENTER CHANNEL GUARD --
TINT CENTER AUTO SHUT OFF OFF
WHITE BALANCE COOL VIDEO-3 SETTING COMPONENT
PICTURE FEATURES INSTALL
A.A.C ON LANGUAGE ENGLISH
AUTO VNR AUTO AUTO PROGRAM --
COLOUR SYSTEM TV: According to preset CH EDIT / MANUAL PRESET CH only
VIDEO: AUTO PAL Others: blank
ZOOM REGULAR DEMO
ECO SENSOR OFF DEMO OFF
PICTURE TILT CENTER OTHERS
SOUND SETTING VOLUME Appropriate sound level
BASS CENTER CHANNEL PRESET Refer to Operating Instructions.
TREBLE CENTER CHANNEL POSITION 1 POSITION
BALANCE CENTER SUB POWER ON
AI VOLUME ON ON SCREEN DISPLAY POSITION INDICATION
BBE ON TV/VIDEO TV
SPATIALIZER OFF SOUND SYSTEM B/G

AV-25P8
No. 56070 5
SERVICE ADJUSTMENTS
■Initial Setting Value
[INITIAL SETTING VALUES OF VSM PRESET (SUB MENU 5. VSM PRESET)]
[SETTING OF WHITE BALANCE PRESET (SUB MENU 6. WB PRESET)]
■SETTING OF VSM PRESET (Page 18)
2. CONT +17 +0−4
3. COLOR +0+0−1
4. SHARP +0 +0 −3
5. TINT +0 +0 +0
PICTURE
MODE BRIGHT STANDARD SOFT
ITEM
1. BRIGHT +0 +0 +0
■SETTING OF WHITE BALANCE PRESET (Page 19)
WHITE BALANCE COOL MID WARM
ITEM
1. R DRIVE 0 −3+26
2. B DRIVE 0 −23 −27
: Do not adjust.
: Do not adjust.

AV-25P8
No. 560706
Adjustment of SUB COLOUR-II (Page 22)
Adjustment of SUB TINT-II (Page 23)
Adjustment part Description
5. COLOUR
PAL COLOUR Value (A) in the figure: Set to 0V (W & G).
SECAM COLOUR Value (A) in the figure: Set to −5V (W & G).
NTSC 3.58 COLOUR Value (A) in the figure: Set to +6V (W & G).
Adjustment part Description
6. TINT
NTSC 3.58 TINT Value (B) in the figure: Set to +6V (W & Cy).
CONTENTS PAL SECAM NTSC 3.58 NTSC 4.43
R−60
1. CUTOFF G −60
B−60
2. DRIVE R +0
B+0
3. BRIGHT TV 000—
VIDEO +1−4−2—
COMPONENT −3
4. CONT TV 000—
VIDEO +20+2—
COMPONENT +2
5. COLOUR TV / VIDEO +10 +18 +0−2
COMPONENT +8+18
6. TINT TV +6+6−10
VIDEO +6+6+60
COMPONENT +6−3
7. BLACK OFFSET R-Y —0——
B-Y —0——
8. SHARP TV −15 −17 −15 —
VIDEO −13 −11 −12 —
COMPONENT −15
■VIDEO / CHROMA CIRCUIT ADJUSTMENT (Page 19)
: Do not adjust.

AV-25P8
No. 56070 7
■DEFLECTION CIRCUIT ADJUSTMENT (Page 25)
[DEFLECTION ADJUSTMENTS INITIAL SETTING VALUE (SUB MENU 4. DEF)]
: Do not adjust.
■AUDIO CIRCUIT ADJUSTMENT (Page 29)
[AUDIO ADJUSTMENTS INITIAL SETTING VALUE (SUB MENU 3. AUDIO)]
Setting item Variable range Fixed value
1. ERROR LIMIT 000H ~ FF0H 100H
2. A2 ID THR 00H ~ FFH 14H
3. BASS −17 ~ +17 +0
4. TREBLE −17 ~ +17 +0
: Do not adjust.
Initial setting value
Setting item Adjustment name REGULAR ZOOM 16:9
50Hz 60Hz 50Hz 60Hz 50Hz 60Hz
1. V-SHIFT Vertical shift −30+10−10
2. V-SIZE Vertical size +13 0 +36 +35 −37 −37
3. SUBTITLE Subtitle 0 +10+70 0
4. H-CENT Horizontal center −9+5−1−10 0
5. H-SIZE Horizontal size +11 −1−9−7−10
6. EW-PIN Side pin correction −1−1−4−5+2+1
7. TRAPEZ Trapezoidal distortion correction +4−10 0−1+1
8. EW.COR.L Corner pin correction Low side −20 0 0+1+1
9. EW.COR.H Corner pin correction High side −20 0 0+1+1
10. V.S-COR Vertical size correction +900000
11. V-LIN Vertical Linearity 0 0 +1000
12. H-BLK-R Horizontal Blanking Right 0 0 0 0 +29 0
13. H-BLK-L Horizontal Blanking Left 0 0 0000
14. V-EHT V size correction level caused by EHT change −400000
15. H-EHT H size correction level caused by EHT change −400000
16. EHT-GAIN Size correction gain caused by EHT change 0 0 0000

AV-25P8
No. 560708 CTH 0009
CRT
AV25P8PH-SK #3
VICTOR COMPANY OF JAPAN, LIMITED
TELEVISION RECEIVER DIVISION 1106 Heta, Iwai-city, Ibaraki-prefecture, 306-0698, Japan

No.51752
Aug. 2000
A
V-25P
X
1COPYRIGHT © 2000 VICTOR COMPANY OF JAPAN, LTD.
AV-25PX
CONTENTS
!SPECIFICATIONS ････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････ ･････････････････････････････
･･････････････････････････････････････････････････････････
･････････････････････････････ 2
!SAFETY PRECAUTIONS ････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････ ･･･････････････････････
･･････････････････････････････････････････････
･･･････････････････････ 3
!FEATURES････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････ ････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････ ･･･
･･････
･･･ 4
!FUNCTIONS････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････ ････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････ ･･
････
･･ 5
!SPECIFIC SERVICE INSTRUCTIONS ････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････ ･････････････
･･････････････････････････
･････････････ 6
!SERVICE ADJUSTMENTS ････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････ ･････････････････････
･･････････････････････････････････････････
･････････････････････ 12
★
STANDARD CIRCUIT DIAGRAM (APPENDIX) ････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････ ･････
･･････････
･････ 2-1
!PARTS LIST････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････ ････････････････････････････････
････････････････････････････････････････････････････････････････
････････････････････････････････ ･
･･
･33
SERVICE MANUAL
COLOUR TELEVISION
BASIC CHASSIS
JK

No.51752
A
V-25PX
2
SPECIFICATIONS
Item CONTENTS
Dimensions ( W×
××
×H×
××
×D ) 655mm×530.5mm×465mm
Mass 36.0kg
TV RF System B, G, I, D, K, K1, M
Colour System PAL, SECAM, NTSC3.58, NTSC4.43
Stereo System Play back stereo system
Receiving Frequency VHF(L) 46.25MHz～168.25MHz
VHF (H) 175.25MHz～463.25MHz
UHF 471.25MHz ～863.25MHz
CATV Mid(X-Z, S1-S10), Super(S11-S20), Hyper(S21-S41) bands receivable
Intermediate Frequency
VIF Carrier 38.0MHz
SIF Carrier 33.5MHz(4.5MHz), 32.5MHz(5.5MHz), 32.0MHz(6.0MHz), 31.5MHz(6.5MHz)
Colour Sub Carrier Frequency
PAL 4.43MHz
SECAM 4.40625MHz, 4.25MHz
NTSC 3.58MHz / 4.43MHz
Power Input AC 110V～240V , 50/60Hz
Power Consumption 181W(Max) / 119W(Avg)
Picture Tube Visible size : 60cm measured diagonally
High Voltage 31.0kV±1.5kV (at zero beam current)
Speaker & Audio Output Open dome speaker
10W+10W, 10cm round×2
Video Audio Input terminals
S-Video Y : 1V(p-p) positive (Negative sync provided, when terminated with 75Ω)
C : 0.286V(p-p) (Burst signal, when terminated with 75Ω)
Video 1V(p-p) 75Ω(RCA pin jack)
Video1
Audio(L/R) 500mV(rms) (-4dBs), High impedance (RCA pin jack)
Video 1V(p-p) 75Ω(RCA pin jack) Video2
Audio(L/R) 500mV(rms) (-4dBs), High Impedance (RCA pin jack)
Video/Y V : Composite video 1V(p-p) 75Ω(RCA pin jack)
Y : Component video 1V(p-p) 75Ω(RCA pin jack)
Cb Component video B-Y 0.7V(p-p) 75Ω(RCA pin jack)
Cr Component video R-Y 0.7V(p-p) 75Ω(RCA pin jack)
Video3
Audio(L/R) 500mV(rms) (-4dBs), High Impedance (RCA pin jack)
Video 1V(p-p) 75Ω(RCA pin jack) Video4
(
Front terminal
)
Audio(L/R) 500mV(rms) (-4dBs), High impedance (RCA pin jack)
Video Audio Output terminal
Video 1V(p-p) 75Ω(RCA pin jack)
Audio(L/R) 500mV(rms) (-4dBs), High Impedance (RCA pin jack)
Aerial Input Terminal 75Ωunbalanced, Coaxial
Headphone jack Stereo mini jack (φ3.5mm )
AV Compu Link terminal AV Compu LinkⅡ, mini jack (φ3.5mm )
Remote Control Unit RM-C113 (AA/R06 dry battery×2)
Design & specifications are subject to change without notice.

No.51752
A
V-25P
X
3
SAFETY PRECAUTIONS
1. 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 those used in the original
circuits. Service should be performed by qualified personnel
only.
2. 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 will further relieve the manufacturer
of responsibility for personal injury or property damage resulting
therefrom.
3. 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 by (!
!!
!) 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.
4. 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 : (") side GND, the
ISOLATED(NEUTRAL) : (#) side GND and EARTH : ($) side
GND. Don't 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 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
that the B1 setting should be checked or adjusted (See
ADJUSTMENT OF B1 POWER SUPPLY).
6. 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
alternatives approved by the manufacturer of the complete
product.
7. Do not check high voltage by drawing an arc. Use a high voltage
meter or a high voltage probe with a VTVM. Discharge the
picture tube before attempting meter connection, by connecting
a clip lead to the ground frame and connecting the other end of
the lead through a 10k!2W resistor to the anode button.
8. 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. Always use the manufacturer's replacement
components.
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, screw"heads, 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 exposed metal part having a
return 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
in the 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
(r.m.s.).
"
""
"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 1500!10W resistor paralleled by a 0.15#F
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 return 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 corresponds 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.).
0.15
μ
F AC-TYPE
1500
!
10W
GOOD EARTH GROUND
PLACE THIS PROBE
ON EACH EXPOSED
METAL PART
AC VOLTMETER
(HAVING 1000
!
/V,
OR MORE SENSITIVITY)

No.51752
A
V-25PX
4
FEATURES
"By preference, users can select the picture size from REGULAR,
ZOOM, 16:9 modes.
"Users can make fun to connect the Digital Video Disk player by
using the component video signal input terminal.
"Built-in ECO (ECONOMY, ECOLOGY) MODE.
In accordance with the brightness in a room, the brightness
and/or contrast of the picture can be adjusted automatically to
make the optimum picture which is easy on the eye.
"I
2C Bus controls the many ICs which have various functions each
other.
I2C BUS CONTROL SYSTEM CHART
IC1701
MICRO
COMPUTER
IC1701
MICRO
COMPUTER
IC1301
VIDEO
CHROMA
IC1301
VIDEO
CHROMA IC1501
DEF CTRL
IC1501
DEF CTRL IC1201
SRT
IC1201
SRT IC8801
LED CTRL
IC8801
LED CTRL
IC301 [0S]
DIGI COMB
IC301 [0S]
DIGI COMB IC101 [0S]
AV SW
IC101 [0S]
AV SW
IC1702
MEMORY
IC1702
MEMORY
SCL2 / SDA2
SCL3 / SDA3
TU1001
TUNER
TU1001
TUNER
SCL1 / SDA1

No.51752
A
V-25P
X
5
FUNCTIONS
①Headphone jack ⑥TV/VIDEO ⑪POWER
②Video-4 terminal ⑦ECO sensor ⑫Main POWER SW
③OK ⑧Remote control sensor
④Channel -/+ (MENU UP/DOWN) ⑨ECO
⑤Volume -/+ (MENU LEFT/RIGHT) ⑩ON TIMER
①Video-1 terminal (S,V,L,R)
②Video-2 terminal (V,L,R)
③Video-3 terminal (V/Y,Cb,Cr,L,R)
④Output terminal (V,L,R)
⑤AV COMPULINK terminal
⑥Aerial socket
①POWER
②PICTURE MODE
③COLOUR
④MENU OK
⑤TV / VIDEO
⑥SPATIALIZER
⑦DISPLAY
⑧ZOOM
⑨MENU UP/DOWN
⑩MENU LEFT RIGHT
⑪AUTO VNR
⑫AAC
⑬CHANNEL
⑭CHANNEL SCAN
⑮CHANNEL +/-
⑯VOLUME +/-
⑰MUTING
■
■■
■FRONT PANEL
■
■■
■REAR TERMINAL
■
■■
■REMOTE CONTROL UNIT(RM-C112)

No.51752
A
V-25PX
6
SPECIFIC SERVICE INSTRUCTIONS
DISASSEMBLY PROCEDURE
REMOVING THE REAR COVER
1.Disconnect the power plug from wall outlet.
2.As shown in the Fig.2, remove the 14 screws marked A
AA
A.
3.Withdraw the rear cover toward you.
REMOVING THE CHASSIS
"After removing the REAR COVER.
1.Slightly raise the both sides of the chassis by hand and remove the
2claws under the both sides of the chassis from the front cabinet.
2.Withdraw the chassis backward.
(If necessary, take off the wire clamp, connectors etc.)
REMOVING THE AV TERMINAL BOARD
"After removing the REAR COVER.
1.As shown in Fig.2, remove the 5screws marked B
BB
B.
2.Then remove the AV TERMINAL BOARD.
REMOVING THE SPEAKER BOX
"After removing the REAR COVER.
1.As shown in Fig. 2, removing the 2screws marked C
CC
C,then
remove the speaker box.
2.Follow the same steps when removing the other hand speaker
box.
NOTE : When removing the screws marked C
CC
Cof the speaker box,
remove the lower side screw first, and then remove the
upper one.
REMOVING THE CONTROL BASE
"After removing the chassis.
1.As shown in Fig.1, while pushing down the claws marked D
DD
D
remove the CONTROL BASE in the arrow direction E
EE
E.
CHECKING THE PW BOARD
To check the PW Board from back side.
1. Pull out the chassis (refer to REMOVING THE CHASSIS).
2. Erect the chassis vertically so that you can easily check the back
side of the PW Board.
CAUTION
"When erecting the chassis, be careful so that there will be no
contacting with other PW Board.
"Before turning on power, make sure that the wire connector is
properly connected.
"When conducting a check with power supplied, be sure to
confirm that the CRT EARTH WIRE (BRAIDED ASS’
’’
’Y) is
connected to the CRT SOCKET PW board.
WIRE CLAMPING AND CABLE TYING
1. Be sure to clamp 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 with a
new cable tie.
E
EE
E
D
DD
D
CONTROL BASE
CHASSIS
Fig. 1
CLAW
,

No.51752
A
V-25P
X
7
C
CC
C
FRONT CABINET
CRT
CRT SOCKET PWB
FRONT CONTROL
PWB
MAIN PWB
CLAW
CLAW
HVT
CHASSIS
BASE
AV TERMINAL
BOARD
POWER CORD
REAR COVER
AV SEL. PWB
Fig.2
POWER &
DEF PWB
B
BB
B
C
CC
C
A
AA
A

No. 51752
AV-25PX
8
REPLACEMENT OF MEMORY ICs
1. Memory ICs
This model uses memory ICs. This memory IC data are for proper
operation of the video and deflection circuits. When replacing, be sure to
use ICs written with the initial values of data.
2. Procedure for replacing memory ICs
(1) Power off
Switch off the power and disconnect the power plug from the wall outlet.
(2) Replace the memory IC
Be sure to use memory ICs written with the initial data values.
(3) Power on
Connect the power plug into the wall outlet and switch power on.
(4) Check and set SYSTEM CONSTANT SET
It must not adjust without signal.
1) Should be open the door on the surface of the remote control unit. Then DVD
control buttons and PICTURE MODE button will be appeared.
2) Press the DISPLAY key and the PICTURE MODE key of the REMOTE
CONTROL UNIT simultaneously.
3) The SERVICE MENU screen of Fig. 1 will be displayed.
4) While the SERVICE MENU is displayed, again press the DISPLAY key and
PICTURE MODE key simultaneously, and the SYSTEM CONSTANT SET
screen of Fig. 2 will be displayed.
5) Check the setting values of the SYSTEM CONSTANT SET of Table 1 in page
later. If the value is different, select the setting item with the MENU UP/DOWN
key, and set the correct value with the MENU LEFT/RIGHT key.
6) Press the OK key to memorize the setting value.
7) Press the DISPLAY key twice, and return to the normal screen.
(5) Receive channel setting
Refer to the OPERATING INSTRUCTIONS, and set the receive channels as
described.
(6) User settings
Check the user setting items according to Table 2. Where these do not agree, refer
to the OPERATING INSTRUCTIONS.
(7) SERVICE MENU setting
Verify what to see in the SERVICE MENU, and set what ever in necessary.
SERVICE MENU
1. IF 2. V/C
3. AUDIO 4. DEF
5. VSM PRESET 6. WB PRESET
7. AUTO PROGRAM (OFF)
1-7 : SELECT : EXIT
SERVICE MENU
JVC JK ASIA V**
M*******-*****
DISP
SYSTEM CONSTANT SET
COLOUR : MULTI
MSP : NO
SUPER BASS : NO
CENTER SPEAKER : NO
TEXT : NO
MODEL=JK_ASIA(V*.***)
OK :STORE DISP :EXIT
SYSTEM CONSTANT(1/3)
SYSTEM CONSTANT SET
BLUE BACK MUTE : NO
VOLUME LIMIT : YES
COLOUR AUTO : NO
TILT : NO
C-TRAP : 1
OK :STORE DISP :EXIT
MODEL=JK_ASIA(V*.***)
SYSTEM CONSTANT(2/3)
Fig.2
Fig.1
SYSTEM CONSTANT SET
E.M.C. : NO
N/S WHITE BACK : NO
7 LED SPEED : 00
OK :STORE DISP :EXIT
MODEL=JK_ASIA(V*.***)
SYSTEM CONSTANT(3/3)
MENU
LEFT/RIGHT
MENU
UP/DOWN
PICTURE
MODE
DISPLAY
OK
KEY ASSIGNMENT OF REMOTE CONTROL UNIT

No. 51752
AV-25PX
9
INITIAL SETTING VALUES OF SYSTEM CONSTANT SET (TABLE 1)
CONTENTS VARIABLE RANGE INITIAL SETTING VALUE
COLOUR MULTI
MSP NO
SUPER BASS NO
CENTER SPEAKER NO
TEXT NO
BLUE BACK MUTE NO
VOLUME LIMIT YES
COLOUR AUTO NO
TILT NO
C-TRAP 1
E.M.C. NO
N/S WHITE BACK NO
7 LED SPEED 00
USER SETTING CONDITIONS (TABLE2)
PICTUIRE SETTING FEATURES
PICTURE MODE
CONTRAST
BRIGHT
SHARP
COLOUR
TINT
WHITE BALANCE
STANDARD
CENTER
COOL
PICTURE FEATURES
SLEEP TIMER
ON TIMER
BLUE BACK
CHILD LOCK
CHANNEL GUARD
AUTO SHUT OFF
VIDEO-3 SETTING
OFF
ON
OFF
OFF
COMPONENT
INSTALL
LANGUAGE
AUTO PROGRAM
EDIT / MANUAL PRESET CH only
Others : blank
DEMO
AAC
AUTO VNR
COLOUR SYSTEM
ZOOM
ECO SENSER
PICTURE TILT
OFF(TV) / ON(VIDEO)
AUTO
TV : According to preset CH
VIDEO : AUTO
REGULAR
DISPLAY
CENTER DEMO OFF
SOUND SETTING
STEREO / Ⅰ・Ⅱ
BASS
TREBLE
BALANCE
AI VOLUME
BBE
SPATIALIZER
CENTER
ON
ON
ON
MULTI TRIPLE PAL
YES NO
YES NO
YES NO
YES NO
YES NO
YES NO
YES NO
YES NO
1 0
YES NO
00 10 20 1250 1260 1270
……
YES NO

No. 51752
AV-25PX
10
SERVICE MENU SETING ITEMS (TABLE 3)
Setting item Setting value Setting item Setting value
1. IF VCO 4. DEF 1. V-SHIFT
2. V-SIZE
3. SUBTITLE
4. H-CENT
5. H-SIZE
6. EW-PIN
7. TRAPEZ
8. EW. COR. L
9. EW. COR. H
10. V. S-COR
11. V-LIN
12. H-BLK-R
13. H-BLK-L
14. V-EHT
15. H-EHT
16. EHT-GAIN
2. V / C 1. CUT OFF (R, G, B)
2. DRIVE ( R, B)
3. BRIGHT
4. CONT.
5. COLOUR
6. TINT
7. BLACK OFFSET (R-Y, B-Y)
8. SHARP
5. VSM PRESET
BRIGHT
STANDARD
SOFT
1. BRIGHT
2. CONT
3. COLOUR
4. SHARP
5. TINT
6. WB PRESET
COOL
MID
WARM
1. R DRIVE
2. B DRIVE
3. AUDIO
(Do not adjust) 1. ERROR LIMIT
2. A2 ID THR
3. BASS
4. TREBLE
7. AUTO PROGRAM
(Do not adjust) ON / OFF

No. 51752
AV-25PX
11
REPLACEMENT OF CHIP COMPONENT
!CAUTIONS
1. Avoid heating for more than 3 seconds.
2. Do not rub the electrodes and the resist parts of the pattern.
3. When removing a chip part, melt the solder adequately.
4. Do not reuse a chip part after removing it.
!SOLDERING IRON
1. Use a high insulation soldering iron with a thin pointed end of it.
2. A 30w soldering iron is recommended for easily removing parts.
!REPLACEMENT STEPS
1. How to remove Chip parts
"
""
"Resistors, capacitors, etc
(1) As shown in the figure, push the part with tweezers and
alternately 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 each lead.
(2) As shown in the figure, push the part with tweezers and
alternately melt the solder at each lead. Shift and remove the
chip part.
Note : After removing the part, remove remaining solder from the
pattern.
2. How to install Chip parts
"
""
"Resistors, capacitors, etc
(1) Apply solder to the pattern as indicated in the figure.
(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.
"
""
"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 solder lead
Aas indicated in the figure.
(4) Then solder leads
Band C.
SOLDER SOLDER
AB
C
A
B
C

No. 51752
AV-25PX
12
SERVICE ADJUSTMENTS
BEFORE STARTING SERVICE ADJUSTMENT
1. There are 2 ways of adjusting this TV: One is with 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 values. The setting values
which adjust the screen to its optimum condition may differ
from the initial setting values.
3. Make sure that connection is correctly made to AC power
source.
4. Turn on the power of the set and equipment before use, and
start the adjustment procedures after waiting at least 30 minutes.
5. Unless otherwise specified, prepare the most suitable reception
or input signal for adjustment.
6. Never touch any adjustment parts, which are not specified in the
list for this adjustment variable resistors, transforms, condensers,
etc.
7. Preparation for adjustment (presetting)
Unless otherwise specified in the adjustment items, preset the
following functions with the REMOTE CONTROL UNIT.
User mode setting condition
PICTURE MODE (VSM) STANDARD
WHITE BALANCE MID
ZOOM REGULAR
CONTRAST CENTER
BRIGHT CENTER
SHARP CENTER
COLOUR CENTER
AAC OFF
AUTO VNR OFF
PICTURE TILT CENTER
BLUE BACK OFF
AUTO SHUTOFF OFF
ECO SENSOR OFF
AI VOLUME OFF
BBE OFF
SLEEP TIMER OFF
BALANCE CENTER
SPATIALIZER OFF
MEASURING INSTRUMENT AND FIXTURES
1. DC voltmeter (or digital voltmeter)
2. Oscilloscope
3. Signal generator (Pattern generator) [PAL / SECAM / NTSC]
4. Remote control unit
ADJUSTMENT CONTENTS
●CHECK OF B1 POWER SURPLY
●CHECK OF HIGH VOLTAGE
●FOCUS ADJUSTMENT
●CHECK OF IF CIRCUIT
●SETTING OF VSM PRESET
●SETTING OF WHITE BALANCE PRESET
●VIDEO / CHROMA CIRCUIT ADJUSTMENT
●DEFLECTION CIRCUIT ADJUSTMENT
●AUDIO CIRCUIT ADJUSTMENT [Do not adjust]
●PURITY, CONVERGENCE ADJUSTMENT