JVC AV-21L81B(-BK), AV-25L81B(-BK), AV-29L81B(-BK) Service Manual
SERVICE MANUAL
COLOUR TELEVISION
AV-21L81B
AV-25L81B
AV-29L81B
BASIC CHASSIS
CH
POWER
DISPLAY
MENU
SUPER
BASS
CHANNEL VOLUME
SYSTEM
COLOUR
SOUND MUTING
TV/VIDEO
123
I/II
456
PICTURE MODE
7809
CHANNEL SCAN
RETURN
-/--
OFF TIMER
ECO SENSOR
RM-C358 REMOTE CONTROL UNIT
RM-C358-1C
[AV-21L81B
(-BK)
, AV-25L81B
AV-21L81B
AV-25L81B
AV-29L81B
DISPLAY
SUPER
BASS
COLOUR
TV/VIDEO
PICTURE MODE
CHANNEL SCAN
MENU
CHANNEL VOLUME
SYSTEM
SOUND MUTING
123
I/II
456
7809
RETURN
ECO SENSOR
RM-C358 REMOTE CONTROL UNIT
(-BK)
(-BK)
(-BK)
POWER
-/--
OFF TIMER
RM-C358-1C
(-BK)
] [AV-29L81B
(-BK)
]
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 ...........................................................................................................................................49
COPYRIGHT © 2001 VICTOR COMPANY OF JAPAN, LTD.
No. 51853
Oct. 2001
AV-21L81B
AV-25L81B
AV-29L81B
SPECIFICATIONS
Items
Dimensions (W × H × D)
Mass 24kg 30kg 50kg
TV RF System B, G, I, D, K
Colour System TV Mode PAL / SECAM / NTSC3.58 / NTSC4.43
VIDEO Mode PAL / SECAM / NTSC3.58 / NTSC4.43
Stereo System Playback Only (RF A2 BILINGUAL only)
Receiving Frequency VHF (VL) 43.75MHz – 142.25MHz 46.25MHz – 140.25MHz
VHF (VH) 142.28MHz – 428.75MHz 147.25MHz – 423.25MHz
UHF 428.78MHz – 865.75MHz 431.25MHz – 863.25MHz
CATV ● Cable TVs of Mid (X-Z, S1-S10)
Intermediate VIF Carrier 38.0MHz
Frequency 31.5MHz (6.5MHz)
SIF Carrier 32.0MHz (6.0MHz)
Colour Sub Carrier Frequency PAL (4.43MHz), SECAM (4.40625MHz / 4.25MHz)
Aerial Input Terminal 75Ø Unbalanced
Power Input AC110 – 240V, 50 / 60Hz
Power Consumption 141W
Picture Tube (Vsible size) 51cm measured diagonally 60cm measured diagonally 68cm measured diagonally
High Voltage (at cut-off in service mode)
Speaker MAIN : 5 × 12cm Oval type ×2, 7W +7W 3.5cm + 10cm, Round taye ×2
Video / Audio Input (1 / 2 / 3) Video(1,3) : 1Vp-p, 75Ø (RCA pin jack)
AV-21L81B-BK
59.8cm × 47.43cm × 47.15cm 68.2cm × 54.33cm × 47.75cm 73.2cm × 58.8cm × 51.8cm
Super (S11-S20) & Hyper (S21-S41) bands receivable
32.5MHz (5.5MHz)
NTSC (3.58MHz / 4.43MHz)
(Max.)
/ 88W
(Avg.)
29kV ± 1kV 31kV ± 1kV 32kV +1/–1.5kV
BASS BLASTER UNIT : φ13cm, 13W 15W + 15W
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
169W (Max.) / 106W (Avg.) 195W(Max.)/120W(Avg.)
Contents
AV-25L81B-BK
AV-29L81B-BK
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-C358-1C
(Battery size: AA/R06/UM-3 × 2)
Design & specifications are subject to change without notice.
2 No. 51853
SAFETY PRECAUTIONS
AC VOLTMETER
(HAVING 1000Ω/V,
OR MORE SENSITIVITY)
PLACE THIS PROBE
ON EACH EXPOSED
ME TAL PAR T
1500Ω 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-21L81B
AV-25L81B
AV-29L81B
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. 51853 3
AV-21L81B
AV-25L81B
AV-29L81B
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.
s I 2 C bus control utilizes single chip ICs.
s Built-in bass blaster circuit reinforces bass sound.
[Only AV-21L81B-BK, AV-25L81B-BK]
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. 51853
FUNCTIONS
RM-C358 REMOTE CONTROL UNIT
DISPLAY
SUPER
BASS
MENU
POWER
CHANNEL VOLUME
SYSTEM
COLOUR
OFF TIMER
TV/VIDEO
PICTURE MODE
CHANNEL SCAN
ECO SENSOR
SOUND MUTING
RETURN
123
456
7809
-/--
I/II
a FRONT PANEL
[AV-21L81B-BK, AV-25L81B-BK]
[AV-29L81B-BK]
L/MONOVR
IN (VIDEO-3)
AV-21L81B
AV-25L81B
AV-29L81B
a REAR PANEL
[AV-21L81B-BK, AV-25L81B-BK]
VIDEO-1
INPUT
V
BASS
SPEAKER
L
/
MONO
OUT
[AV-29L81B-BK]
VIDEO-1
INPUT
V
L
/
MONO
R
COMPONENT
(
VIDEO-2
INPUT
Y
/
V
C
B
L
/
RRC
R
)
MONO
OUTPUT
V
L
COMPONENT
(
VIDEO-2
INPUT
Y
/
V
C
B
L
/
RRR C
R
)
MONO
a REMOTE CONTROL UNIT
RM-C358-1C
OUTPUT
V
L
No. 51853 5
AV-21L81B
AV-25L81B
SPECIFIC SERVICE INSTRUCTIONS
DISASSEMBLY PROCEDURE [AV-21L81B-BK, AV-25L81B-BK]
REMOVING THE TWIN PORT BASS BLASTER UNIT
1. Unplug the AC power cord.
2. Disconnect the Twin Port Bass Blaster Unit's cord from the rear of
the TV set.
3. Remove the Twin Port Bass Blaster Unit by pulling it upward.
REMOVING THE REAR COVER
After removing the twin port bass blaster unit.
•
1. Remove the 7 or 9 screws marked Å and 4 screws maked ı as
shown in Fig.1.
2. 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 MAIN PW BOARD
After removing the rear cover.
•
1. Slightly raise the both sides of the Main PWB by hand, take off the
PB Stopper marked Ç from the front cabinet.
2. Withdraw the Main PWB backward.
(If necessary, take off the wire clamp and connectors, etc.)
REMOVING THE SPEAKER
After removing the rear cover.
•
1. Remove the 2 screws marked Î and 2 screws maked ´ as shown
in Fig.1.
2. Follow the same steps when removing the other hand speaker.
CHECKING THE MAIN PW BOARD
1. To check the back side of the Main PWB.
1) Pull out the Main PWB. (Refer to REMOVING THE MAIN PW
BOARD).
2) Erect the Main PWB vertically so that you can easily check its
back side.
[CAUTION]
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.
6 No. 51853
CRT SOCKET PWB
MAIN PWB
PB STOPPER
TWIN PORT
BASS BLASTER UNIT
(×4)
B
(×2)
(×2)
E
(×2)
E
D
(×2)
D
C
REAR COVER
SPEAKER
A
SPEAKER
FRONT CABINET
PICTURE TUBE
(×7) [AV-21L81B-BK]
(×9) [AV-25L81B-BK]
Except 21”
model
Except 21” model
AV-21L81B
AV-25L81B
Fig.1
No. 51853 7
AV-29L81B
DISASSEMBLY PROCEDURE [AV-29L81B-BK]
REMOVING THE REAR COVER
1. Unplug the AC power cord.
2. Remove the 16 screws marked Å as shown in Fig. 2.
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. 2.
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.
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. 2.
2. When you pull out the AV Terminal board in the direction of arrow
marked Î as shown in Fig. 2, 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. 3.
2. When you pull out the Control base in the direction of arrow maked
as shown in Fig. 3.
Ï
(If necessary, take off the wire, connector’s 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. 2.
2. Follow the same step for removing the other hand speaker box.
8 No. 51853
PICTURE TUBE
[FRONT SIDE]
CONTROL BASE
AV-29L81B
E
FRONT CABINET
FRONT CONTROL
PWB (1/2)
CONTROL BASE
CRT
SOCKET PWB
Fig. 3
F
CHASSIS
BASE
Fig.3
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. 2
No. 51853 9
AV-21L81B
AV-25L81B
AV-29L81B
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. 4).
2. While keeping the surface of CRT down, mount the TV set on the
CRT change table balanced will as shown in Fig. 5.
3. Remove 4 screws marked by arrows with a box type screwdriver as
shown in Fig. 5.
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. 6.
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. 4
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. 7.
1. Wipe around the anode button with clean and dry cloth. (Fig. 7)
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. 8)
夝 Silicon grease product No. KS - 650N
CRT
Anode button
CABINET
Approx.
20mm (Do not
coat grease on
this section
Fig. 5
CRT
CRT
CHANGE TABLE
Fig. 6
Silicon grease
should be coated
by 5mm or more
from the outside
diameter of anode
cap.
Silicon grease
coating
Fig. 7
10 No. 51853
Anode button
(No sticking of
silicon grease)
Coating position
of silicon grease
Anode cap
Fig. 8
REPLACEMENT OF MEMORY IC
AV-21L81B
AV-25L81B
AV-29L81B
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
6. PLUG & PLAY (OFF)
1-6 : SELECT DISPLAY : EXIT
2. VC
4. VSM PRESET
******* **** ***** *****
**** **** *** ***
SYSTEM CONSTANT-
SYSTEM CONSTANT SET 1
SYSTEM
COMB
TILT
TEXT
SUPER BASS
LANGUAGE
-
89 : SEL
+ : OPE DISP : EXIT
Ι
MULTI
YES
YES
NO
NO
E / R / A / F
NAME OF REMOTE CONTROL KEYS
DISPLAY
MENU
PICTURE
MODE
DISPLAY
MENU
SUPER
BASS
CHANNEL VOLUME
SYSTEM
COLOUR
SOUND MUTING
TV/VIDEO
PICTURE MODE
CHANNEL SCAN
123
I/II
456
7809
RETURN
ECO SENSOR
POWER
OFF TIMER
SYSTEM CONSTANT-
SYSTEM CONSTANT SET 2
MSP
MENU
MENU
MENU
+
BILINGUAL
B / B SOUND
TUNER
COLOUR AUTO
89 : SEL
-
+ : OPE DISP : EXIT
SYSTEM CONSTANT-
SYSTEM CONSTANT SET 3
-/--
LOCK 1 MHz
156.25 kHz
31.25 kHz
89 : SEL
500 kHz
250 kHz
-
+ : OPE DISP : EXIT
ΙΙ
NO
NO
NO
MU
NO
ΙΙΙ
020
020
020
015
015
No. 51853 11
AV-21L81B
AV-25L81B
AV-29L81B
SETTING OF SYSTEM CONSTANT SET
Setting item Setting content
SYSTEM
COMB
TILT
TEXT
SUPER BASS
LANGUAGE
MSP
BILINGUAL
B/B SOUND
TUNER
COLOUR AUTO
LOCK 1MHz
500KHz
250KHz
156.25KHz
31.25KHz
EASTERN UKRANIAN RUSSIAN
NO PAN EURO ARABIC
MULTI TRIPLE
VIET PAL
YES NO
YES NO
YES PSEUDO NO
E/T E
YES NO
YES NO
YES NO
MU MA
YES NO
000 024
000 024
000 024
000 024
000 024
TRIPLE
NO
NO
NO
YES
E/T
NO
YES
NO
MU
NO
020
020
020
015
015
Setting value
AV-29L81B-BKAV-25L81B-BKAV-21L81B-BK
YES
YES
PSEUDO
Table 1
12 No. 51853
USER SETTING VALUES
Setting item Setting value
SUB POWER ON
CHANNEL POSITION 1 POSITION
CHANNEL PRESET REFER TO OPERATING INSTRUCTIONS
VOLUME 15 ± 2
TV/VIDEO TV
VNR OFF
COMPRESS (16:9) OFF
AUTO SHUTOFF OFF
CHILD LOCK OFF
BLUE BACK ON
VIDEO-2 SET VIDEO
LANGUAGE THAI
MONO SURROUND OFF
AI VOLUME ON
ON SCREEN DISPLAY POSITION INDICATION
COLOUR SYSTEM PAL
SOUND SYSTEM B/G
BILINGUAL MODE I/II
PICTURE MODE-VSM BRIGHT
OFF TIMER 00
ECO SENSOR OFF
SUPER BASS ON
BASS CENTRE
TREBLE CENTRE
BALANCE CENTRE
PICTURE TILT 00 [AV-29L81B-BK]
AV-21L81B
AV-25L81B
AV-29L81B
Table 2
No. 51853 13
AV-21L81B
AV-25L81B
AV-29L81B
SERVICE MENU SETTING ITEMS
Service menu Setting item
1. IF 1. VCO
2. DELAY POINT
2. VC 1. CUTOFF(R/G)
2. DRIVE(R/G/B)
3. BRIGHT
4. CONT
5. COLOUR
6. TINT
7. SHARP
8. YDELAY
3. DEF 1. VER. SLOPE
2. VER. HEIGHT
3. VER. POSITION
4. VER. SCURVE
5. HOR. POSITION
6. HOR. WIDTH
7. EW-PIN
8. EW-TRAPEZ
9. UP CORNER
10. DW CORNER
11. HOR. PARALL
12. HOR. BOW
13. V. ZOOM
Do not adjust
Service menu Setting item
4. VSM PRESET 1. TINT
(BRIGHT/STD/SOFT) 2. COLOUR
Do not adjust
5. PRESET 1. CB
Do not adjust
6.
PLUG & PLAY(OFF)
3. BRIGHT
4. CONT
5. SHARP
2. ACL
3. MUS
4. MAT
5. FCO
6. BPS
7. IFLH
8. VID
9. STM
10. AFCW
11. VSW
12. FFI
13. AGC
14. CL
15. AKB
16. HBL
17. BKS
18. READ STATUS
19. VNR
Table 3
14 No. 51853
Do not adjust
REPLACEMENT OF CHIP COMPONENT
CAUTIONS
a
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
a
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
a
1. How to remove Chip parts
Resistors, capacitors, etc.
(1) As shown in the figure, push the part with tweezers and alter-
nately melt the solder at each end.
AV-21L81B
AV-25L81B
AV-29L81B
2. How to install Chip parts
Resistors, capacitors, etc.
(1) Apply solder to the pattern as indicated in the figure.
(2) Shift with tweezers and remove the chip part.
Transistors, diodes, variable resistors, etc.
(1) Apply extra solder to each lead.
SOLDER
(2) As shown in the figure, push the part with tweezers and alter-
nately melt the solder at each lead. Shift and remove the chip
part.
SOLDER
(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 A as indicated in the figure.
A
B
C
(4) Then solder leads B and C.
A
Note : After removing the part, remove remaining solder from the
pattern.
No. 51853 15
B
C
Loading...