JVC AV-29FT1BUG, AV-29FT1SUG Service Manual

SERVICE MANUAL

COLOUR TELEVISION

YA00720039

AV-29FT1BUG,

AV-29FT1SUG

TABLE OF CONTENTS

1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

2 SPECIFIC SERVICE INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12

COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LIMITED

No.YA007

2003/9

SPECIFICATION

Items

Dimensions ( W × H × D ) 81.2cm × 60.1cm × 52.2cm
Mass 43kg
TV RF System CCIR (B/G, D/K, I , L/L')
Colour System PAL / SECAM / NTSC (Only in EXT mode)
Stereo System A2 (B/G, D/K) / NICAM (B/G, I, D/K, L)
Teletext System Fastext (UK system)

TOP (German system)
WST(World standard system)

Receiving
Frequency

Intermediate
Frequency

Colour Sub
Carrier Frequency

Power Input AC220V ~ AC240V, 50Hz
Power Consumption 72W, standby : 3W
Aerial Input Terminal 75Ω unbalanced, coaxial
Picture Tube Visible size : 68cm (Measured diagonally)
Audio Power Output 7W + 7W
EXT-1 / EXT-2 (Input / Output) 21-pin Euro connector (SCART socket × 2)
EXT-3 (Input) Video 1V(p-p) 75Ω (RCA pin jack × 1)

Headphone Jack Stereo mini jack (Ø3.5mm) × 1
Remote Control Unit RM-C1514B (AAA/R03 dry battery × 2) RM-C1514 (AAA/R03 dry battery × 2)

VHF 47MHz ~ 470MHz
UHF 470MHz ~ 862MHz
French CATV 116MHz ~ 172MHz / 220MHz ~ 469MHz
VIF Carrier 38.9MHz (B/G, D/K, I , L) / 33.95MHz (L')
SIF Carrier 33.4MHz (5.5MHz:B/G)

/ 32.9MHz (6.0MHz:I)
/ 32.4MHz (6.5MHz:L, D/K)

/ 40.45MHz (6.5MHz:L')
PAL 4.43MHz
SECAM 4.40625MHz / 4.25MHz
NTSC 3.58MHz / 4.43MHz

Audio (L/R) 500mV(rms) (-4dBs), High impedance (RCA pin jack × 2)

AV-29FT1BUG AV-29FT1SUG

Contents

Design & specifications are subject to change without notice.

1-2 (No.YA007)

SECTION 1

PRECAUTION

1.1 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 the LIVE side GND and ISOLATED (NEUTRAL)
side GND or EARTH side GND at the same time with a
measuring apparatus (oscilloscope etc.). 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 B1 POWER SUPPLY check).

(6) The high voltage appli ed to the picture tube must confo rm

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 d rawing 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 gr ound frame
and connecting the other end of the lead through a 10kΩ
2W resistor to the anode button.

(8) When service is required, obse rve 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.

a) 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.

b) Leakage Current Chec k

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 1000Ω per volt or more
sensitivity in the following manner. Connect a 1500Ω
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 ac ross 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.).

AC VOLTMETER
(HAVING 1000 /V,
OR MORE SENSITIVITY)

0.15 F AC-TYPE

PLACE THIS PROBE

1500 10W

GOOD EARTH GROUND

ON EACH EXPOSED
METAL PART

(No.YA007)1-3

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

2.1 21-pin Euro connector (SCART) : EXT-1/EXT-2 Pin No. Signal designation Matching value EXT-1 EXT-2

1 AUDIO R output 500mV(rms) (Nominal), Low impedance Used (TV OUT) Used (LINE OUT)
2 AUDIO R input 500mV(rms) (Nominal), High impedance Used (R1) Used (R2)
3 AUDIO L output 500mV(rms) (Nominal), Low impedance Used (TV OUT) Used (LINE OUT)
4 AUDIO GND --- Used Used
5 GND (B) --- Used Used
6 AUDIO L input 500mV(rms) (Nominal), High impedance Used (L1) Used (L2)
7 B input 700mV
8 FUNCTION SW (SLOW SW) Low : 0V-3V, High : 8V-12V, High impedance Used Used

9 GND (G) --- Used NC
10 SCL / T-V LINK --- Not used NC
11 G input 700mV(B-W), 75 Ω Used NC
12 SDA --- Not used NC
13 GND (R) --- Used Used
14 GND (YS) --- Used Used
15 R / C input R : 700mV

C : 300mV
16 Ys input (FAST SW) Low : 0V-0.4V, High : 1V-3V, 75 Ω Used NC
17 GND (VIDEO output) --- Used Used
18 GND (VIDEO input) --- Used Used
19 VIDEO output 1V
20 VIDEO / Y input 1V

(P-P)
(P-P)

21 COMMON GND --- Used Used

, 75 Ω Used NC

(B-W)

(B-W)
(P-P)

, 75 Ω

, 75 Ω

Used (R) Used (C)

(Negative sync), 75 Ω Used (TV OUT) Used (LINE OUT)
(Negative sync), 75 Ω Used Used

(P-P= Peak to Peak, B-W= Blanking to white peak)

[Pin assignment]

20 18 16 14 12 10 8 6 4 2

21 19 17 15 13 11 9 7 5 3 1

1-4 (No.YA007)