JVC AV-29L31(-PH), AV-29L31B(-PH) Service Manual

SERVICE MANUAL
COLOR TELEVISION
AV-29L31 AV-29L31B
BASIC CHASSIS
CH
POWER
DISPLAY
MENU
BASS
CHANNEL VOLUME
CLOSED
MUTING
CAPTION
TV/VIDEO
123
456
PICTURE MODE
7809
RETURN
100
CHANNEL SCAN
OFF TIMER
ECO SENSOR
RM-C249 REMOTE CONTROL UNIT
RM-C249-2C
[AV-29L31B(-PH)]
AV-29L31 AV-29L31B
POWER
DISPLAY
MENU
CHANNEL VOLUME
CLOSED
MUTING
CAPTION
TV/VIDEO
123
456
PICTURE MODE
7809
100
RETURN
CHANNEL SCAN
OFF TIMER
ECO SENSOR
RM-C248 REMOTE CONTROL UNIT
RM-C248-2C
[AV-29L31
(-PH)]
(-PH)
(-PH)

CONTENTS

a SPECIFICATIONS ....................................................................................................................................2
a SAFETY PRECAUTIONS ........................................................................................................................3
a FEATURES ..............................................................................................................................................4
a FUNCTIONS .............................................................................................................................................5
a SPECIFIC SERVICE INSTRUCTIONS ....................................................................................................6
¤ OPERATING INSTRUCTIONS (APPENDIX) ....................................................................................... 1-1
a SERVICE ADJUSTMENTS ....................................................................................................................16
¤ STANDARD CIRCUIT DIAGRAM (APPENDIX) .................................................................................. 2-1
a PARTS LIST ...........................................................................................................................................35
No. 51906
Oct. 2001
AV-29L31 AV-29L31B

SPECIFICATIONS

Items
Dimensions (W × H × D)
Mass 47kg 50kg
TV RF System CCIR(M)
Color System TV Mode NTSC3.58
VIDEO Mode NTSC3.58
Stereo System BTSC (Multi channel Sound)
Receiving Frequency VHF (VL) 54MHz – 88MHz (02 – 06)
VHF (VH) 174MHz – 216MHz (07 – 13)
UHF 470MHz – 806MHz (14 – 69)
CATV Low Band (02 – 06, A-8) by (02 – 06 & 01)
Intermediate VIF Carrier 45.75MHz
Frequency SIF Carrier 41.25MHz (4.5MHz)
Color Sub Carrier Frequency NTSC (3.58MHz)
Aerial Input Terminal 75Ø Unbalanced
Power Input AC110 – 240V, 50/60Hz
Power Consumption 172W
Picture Tube Visible size : 68cm measured diagonally
High Voltage 32kV + 1/–1.5kV (at cut-off in service mode)
Speaker 5cm × 12cm Oval type × 2 3.5cm + 10cm Round type × 2
Audio Output 7W + 7W 15W + 15W
Video / Audio Input (1 / 2 / 3) Video(1,3) : 1Vp-p, 75Ø (RCA pin jack)
73.2cm × 58.8cm × 51.8cm
High Band (07 – 13) by (07 – 13)
Mid Band (A – I) by (14 – 22)
Super Band (J – W) by (23 – 36) (54MHz – 804MHz)
Hyper Band (W+11 – W+23) by (47 – 59)
Ultra Band (W+29 – W+84) by (65 – 125)
Sub Mid Band (A8, A7 – A1) by (01, 93 – 99)
TV/CATV Total Channel 180 Channel
(Max.)
Audio(1,2,3) : 500mVrms ( -4dBs ), High Impedance (RCA pin jack)
Component Input ( Input 2 )
Y : 1Vp-p positive (negative sync provided, when terminated with 75Ø)
CB/CR : 0.7Vp-p 75Ø
AV-29L31-PH AV-29L31B-PH
/ 108W
(Avg.) 195W(Max.) / 120W(Avg.)
Contents
Video/Audio Output 1Vp-p, 75Ø (RCA pin jack)
500mVrms(-4dBs)
Low impedance (400Hz when modulated 100%) (RCA pin jack)
Headphone Jack Stereo mini jack (3.5φ)
Remote Control Unit RM-C248-2C RM-C249-2C
(Battery size: AA/R06/UM-3 × 2)
Design & specifications are subject to change without notice.
2 No. 51906

SAFETY PRECAUTIONS

AC VOLTMETER (HAVING 1000/V, OR MORE SENSITIVITY)
PLACE THIS PROBE ON EACH EXPOSED ME TAL PAR T
1500 10W
0.15µF AC-TYPE
GOOD EARTH GROUND
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 (NEU-
TRAL) 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.
AV-29L31 AV-29L31B
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 1500Ø 10W resistor paralleled by a 0.15µF 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.).
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 10kØ 2W resistor to the anode button.
No. 51906 3
AV-29L31 AV-29L31B

FEATURES

s New chassis design enables use of an interactive on-screen control. s Pure flat CRT produces fine textured picture in every detail. s Wide range voltage (110V ~ 240V) for AC power input. s With AUDIO/VIDEO/COMPONENT input terminals.
2
C bus control utilizes single chip ICs.
s I s By means of AUTO PROGRAM, the TV stations can be selected
automatically and the TV channels can also be rearranged auto­matically.
s Built-in DIGITAL ECO MODE (ECONOMY, ECOLOGY).
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.
s Built-in OFF TIMER & RETURN +.
4 No. 51906

FUNCTIONS

a FRONT PANEL
L/MONOVR
IN (VIDEO-3)
a REAR PANEL
COMPONENT
VIDEO-1
(
)
VIDEO-2
INPUT
INPUT
AV-29L31 AV-29L31B
OUTPUT
V
Y
/
V
C
B
L
/
MONO
R
R
a REMOTE CONTROL UNIT
[AV-29L31-PH]
DISPLAY
CLOSED
CAPTION
TV/VIDEO
PICTURE MODE
CHANNEL SCAN
ECO SENSOR
V
L
L
/
MONO
RRC
RM-C248-2C
MENU
CHANNEL VOLUME
123
456
7809
RETURN 100
POWER
MUTING
OFF TIMER
RM-C249-2C
[AV-29L31B-PH]
DISPLAY
BASS
CHANNEL VOLUME
CLOSED CAPTION
TV/VIDEO
PICTURE MODE
CHANNEL SCAN
RETURN 100
ECO SENSOR
POWER
MENU
123
456
7809
MUTING
OFF TIMER
RM-C248 REMOTE CONTROL UNIT
RM-C249 REMOTE CONTROL UNIT
No. 51906 5
AV-29L31B

SPECIFIC SERVICE INSTRUCTIONS

DISASSEMBLY PROCEDURE [AV-29L31-PH]
REMOVING THE REAR COVER
1. Unplug the AC power cord.
2. Remove the 16 screws marked
3. Withdraw the Rear cover toward you.
[CAUTION]
When reinstalling the rear cover, carefully push it inward after in-
serting the Main PWB into the rear cover groove.
as shown in Fig.1.
Å
REMOVING THE CHASSIS (CHASSIS BASE AND CONTROL BASE)
After removing the rear cover.
1. Slightly raise the both sides of the chassis by hand and remove the 2 claws marked ı under the chassis from the front cabinet as shown in Fig.1.
2. Withdraw the chassis backward.
(If necessary, take off the wire clamp, connector’s etc.)
When conducting a check with power supplied, be sure to confirm
*
that the CRT earth wire is connected to the CRT SOCKET PWB and the Main PWB.
REMOVING THE AV TERMINAL BOARD
After removing the rear cover.
1. Remove the 4 screws marked Ç as shown in Fig.1.
2. When you pull out the AV Terminal board in the direction of arrow marked Î as shown in Fig.1, it can be removed.
CHECKING THE MAIN PW BOARD
1. To check the back side of the Main PWB.
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 Main PWB.
[CAUTION]
When erecting the chassis, be careful so that there will be no con-
tacting with other PW Board. Before turning on power, make sure that the CRT earth wire and
other connectors are properly connected. When repairing, connect the Deg. coil to the DEG. connector on the
Main PWB.
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.
REMOVING THE CONTROL BASE
After removing the rear cover and the chassis.
1. While pushing down the 2 claws maked ´ as shown in Fig. 2.
2. When you pull out the Control base in the direction of arrow maked as shown in Fig. 2.
Ï
(If necessary, take off the wire, connector’s etc.)
REMOVING THE SPEAKER
After removing the rear cover.
1. Remove the 4 screws marked ˝ and 2 screws maked Ó as shown
in Fig.1.
2. Withdraw the speaker backward.
3. Follow the same steps when removing the other hand speaker.
6 No. 51906
PICTURE TUBE
[FRONT SIDE]
CONTROL BASE
AV-29L31B
E
FRONT CABINET
H
G
SPEAKER
(×4)
FRONT CONTROL PWB (1/2)
CONTROL BASE
CRT SOCKET PWB
Fig.2
H
G
SPEAKER
H
F
CHASSIS BASE
Fig.2
(×4)
FRONT CONTROL PWB (2/2)
MAIN PWB
CLAW B
AV TERMINAL BOARD
H
REAR COVER
CHASSIS BASE
CLAW B
A
D
C
(×4)
(×16)
Fig.1
No. 51906 7
AV-29L31B
DISASSEMBLY PROCEDURE [AV-29L31B-PH]
REMOVING THE REAR COVER
1. Unplug the AC power cord.
2. Remove the 16 screws marked Å as shown in Fig. 3.
3. Withdraw the Rear cover toward you.
[CAUTION]
When reinstalling the rear cover, carefully push it inward after in-
serting the Main PWB into the rear cover groove.
REMOVING THE CHASSIS (CHASSIS BASE AND CONTROL BASE)
After removing the rear cover.
1. Slightly raise the both sides of the chassis by hand and remove the
2 claws marked in Fig. 3.
2. Withdraw the chassis backward.
(If necessary, take off the wire clamp, connectors etc.)
When conducting a check with power supplied, be sure to confirm
*
that the CRT earth wire is connected to the CRT SOCKET PWB and the Main PWB.
under the chassis from the front cabinet as shown
ı
REMOVING THE AV TERMINAL BOARD
After removing the rear cover.
1. Remove the 4 screws marked Ç as shown in Fig. 3.
2. When you pull out the AV Terminal board in the direction of arrow
marked Î as shown in Fig. 3, it can be removed.
CHECKING THE MAIN PW BOARD
1. To check the back side of the Main PWB.
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 Main PWB.
[CAUTION]
When erecting the chassis, be careful so that there will be no con-
tacting with other PW Board. Before turning on power, make sure that the CRT earth wire and
other connectors are properly connected. When repairing, connect the Deg. coil to the DEG. connector on the
Main PWB.
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.
REMOVING THE CONTROL BASE
After removing the rear cover and the chassis.
1. While pushing down the 2 claws maked ´ as shown in Fig. 4.
2. When you pull out the Control base in the direction of arrow maked as shown in Fig. 4.
Ï
(If necessary, take off the wire, connectors etc.)
REMOVING THE DOME SPEAKER BOX
After removing the rear cover.
1. Remove the lower side screw marked ˝ first, and then the upper
side screw as shown in Fig. 3.
2. Follow the same step for removing the other hand speaker box.
8 No. 51906
PICTURE TUBE
[FRONT SIDE]
CONTROL BASE
AV-29L31B
E
FRONT CABINET
FRONT CONTROL PWB (1/2)
CONTROL BASE
CRT SOCKET PWB
Fig. 3
F
CHASSIS BASE
Fig. 4
DOME SPEAKER BOX
(×2)
G
FRONT CONTROL PWB (2/2)
MAIN PWB
CLAW B
AV TERMINAL BOARD
G
REAR COVER
DOME SPEAKER BOX
(×2)
CHASSIS BASE
CLAW B
A
D
C
(×4)
(×16)
Fig. 3
No. 51906 9
AV-29L31 AV-29L31B
REMOVING THE CRT
* Replacement of the CRT should be performed by 2 or more persons.
After removing the rear cover, chassis etc.,
1. Putting the CRT change table on soft cloth, the CRT change table
should also be covered with such soft cloth (shown in Fig. 5).
2. While keeping the surface of CRT down, mount the TV set on the
CRT change table balanced will as shown in Fig. 6.
3. Remove 4 screws marked by arrows with a box type screwdriver as
shown in Fig. 6. Since the cabinet will drop when screws have been removed, be
sure to support the cabinet with hands.
4. After 4 screws have been removed, put the cabinet slowly on cloth
(At this time, be carefully so as not to damage the front surface of the cabinet) shown in Fig. 7. The CRT should be assembled according to the opposite sequence
of its dismounting steps.
* The CRT change table should preferably be smaller that the CRT sur-
face, and its height be about 35cm.
CRT CHANGE TABLE
CLOTH
CRT CHANGE TABLE
Fig. 5
CRT
APPROX. 35cm
BOX TYPE SCREW DRIVER
COATING OF SILICON GREASE FOR ELECTRICAL IN­SULATION ON THE CRT ANODE CAP SECTION.
Subsequent to replacement of the CRT and HV transformer or repair
of the anode cap, etc. by dismounting them, be sure to coat silicon grease for electrical insulation as shown in Fig. 8.
1. Wipe around the anode button with clean and dry cloth. (Fig. 8)
2. Coat silicon grease on the section around the anode button. At this
time, take care so that any silicon greases dose not sticks to the anode button. (Fig. 9)
Silicon grease product No. KS - 650N
CRT
Anode button
CABINET
Approx. 20mm (Do not coat grease on this section
Fig. 6
CRT
CRT CHANGE TABLE
Fig. 7
Silicon grease should be coated by 5mm or more from the outside diameter of anode cap.
Silicon grease
coating
Fig. 8
10 No. 51906
Anode button (No sticking of silicon grease)
Coating position of silicon grease
Anode cap
Fig. 9
REPLACEMENT OF MEMORY IC
AV-29L31 AV-29L31B
1. MEMORY IC
This TV uses the following memory IC.
Memory IC: IC1702 on MAIN PW Board
The memory IC memorizes data for correctly operating the video and deflection circuits. When replacing the memory IC, be sure to use the same type IC written with the initial values of data. In other words, use the specific IC listed in PRINTED WIRING BOARD PARTS LIST. For its mounting location, refer to ADJUSTMENT LOCATIONS.
2. PROCEDURE FOR REPLACING MEMORY IC
(1) Power off
Switch the power off and unplug the power cord from the wall outlet.
(2) Replacing the memory IC
Replace the memory IC with new one. Be sure to use the memory IC written with the initial data values.
(3) Power on
Plug the power cord into the wall outlet and switch the power on.
(4) Check and setting of SYSTEM CONSTANT SET:
1) Press the DISPLAY key and the PICTURE MODE key on the remote control unit simultaneously. The SERVICE MENU screen will be displayed.(See Fig.1.)
2) In the SERVICE MENU, press the DISPLAY key and PIC­TURE MODE key simultaneously. Then, the SYSTEM CON­STANT SET screen will be displayed.(See Fig.2.)
3) Check whether the setting values of the SYSTEM CONSTANT SET are the same as those indicated in Table1. If the value is different, select the setting item with the MENU &/^ key, and set the correct value with the MENU –/+key.
4) Press the DISPLAY key twice to return to the normal screen.
(5) Receive channel setting
Refer to the OPERATING INSTRUCTIONS and set the receive channels (channels preset).
(6) User setting
Check the user setting values in Table 2, and if setting value is different, set the correct value. For setting, refer to the OPERATING INSTRUCTIONS.
(7) Setting of SERVICE MENU
Verify the setting for each setting item in the SERVICE MENU.(See Table 3.) If readjustment is necessary, perform ad­justment referring to SERVICE ADJUSTMENTS”.
SERVICE MENU
SERVICE MENU
1. IF
3. DEF
5. PRESET
7. PLUG & PLAY (OFF)
1-7 : SELECT DISPLAY : EXIT
2. VC
4. VSM PRESET
6. AUDIO
******* **** ***** ***** **** **** *** ***
Fig. 1
SYSTEM CONSTANT-
SYSTEM CONSTANT SET 1
COLOR SYSTEM COMB TILT SUPER BASS
89 : SEL
-
+ : OPE DISP : EXIT
Ι
NTSC NO NO NO
NAME OF REMOTE CONTROL KEYS
DISPLAY
DISPLAY
MENU
PICTURE MODE
CLOSED CAPTION
TV/VIDEO
PICTURE MODE
CHANNEL SCAN
ECO SENSOR
MENU
CHANNEL VOLUME
123
456
7809
RETURN
POWER
MUTING
100
OFF TIMER
MENU
MENU
MENU
SYSTEM CONSTANT-
SYSTEM CONSTANT SET 2
MSP B / B SOUND TUNER COLOR AUTO
ΙΙ
YES NO NO MU
+
-
89 : SEL
SYSTEM CONSTANT-
SYSTEM CONSTANT SET 3
LOCK LONG WAIT
89 : SEL
No. 51906 11
+ : OPE DISP : EXIT
SHORT WAIT
-
+ : OPE DISP : EXIT
Fig. 2
ΙΙΙ
: 001 : 001
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