JVC AV-14FMG4/G, AV-14FMG4/S, AV-14FMT4/G Service Manual

YA148200411

SERVICE MANUAL

FLAT COLOUR TELEVISION

AV-14FMG4/G,
AV-14FMG4
AV-14FMT4

/S,

/G

BASIC CHASSIS

CW

[AV-14FMT4/G]

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

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

3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14

5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-28

[AV-14FMG4/G]
[AV-14FMG4/S]

TABLE OF CONTENTS

COPYRIGHT © 2004 Victor Company of Japan, Limited

No.YA148

2004/11

SPECIFICATION

Items

Dimensions (W × H × D) 46.2cm × 34.05cm × 37.5cm

Mass 10kg

TV RF System B, G, I, D, K, M

Colour System TV Mode

Video Mode

Teletext system

Receiving Frequency VHF Low

VHF High

Intermediate Frequency VIF 38.0MHz

Colour Sub Carrier Frequency 4.43MHz (PAL), 4.40MHz/4.25MHz (SECAM), 3.58MHz/4.43MHz (NTSC)

Aerial Input Terminal 75Ω unbalanced, coaxial

Power Input AC110V ~ AC240V, 50Hz / 60Hz

Power Consumption 65W (Max.) / 48W (Avg.)

Picture Tube A34KPU02XX

Screen Size Visible size : 34.0cm (Diagonal) / 28.7cm × 21.7cm (H × V)

High Voltage 22.5kV±1.5kV (at zero beam current)

Speaker 5cm × 9cm, Oval type × 1

Audio Output 3W

Video / Audio Input
[1/2]

Video / Audio Output Video

Headphone 3.5mm stereo mini jack × 1

Remote Control Unit RM-C1261-2H

Video [1/2]
Audio [1/2]

PAL / SECAM / NTSC3.58 / NTSC4.43
PAL / SECAM / NTSC3.58 / NTSC4.43

46.25MHz ~ 168.25MHz (AU0 ~ S10)

175.25MHz ~ 463.25MHz (E5 ~ S41)

UHF

471.25MHz ~ 863.25MHz (E21 ~ CHINA 57)

CATV

Mid : X ~ Z, S1 ~ S10
Super: S11 ~ S20
Hyper: S21 ~ S41

SIF D/K: 31.5MHz (6.5MHz)

I: 32.0MHz (6.0MHz)
B/G: 32.5MHz (5.5MHz)
M: 33.5MHz (4.5MHz)

14-inch, aspect ratio 4:3, conventional type, tinted

1V(p-p), negative sync, 75Ω, RCA pin jack × 2
500mV(rms) (-4dBs ), high impedance, RCA pin jack × 2

1V(p-p), 75Ω, RCA pin jack × 1

Audio

500mV(rms)(-4dBs), Low impedance (400Hz when modulated 100%), RCA pin jack × 1

(AA/R06/UM-3 battery × 2)

AV-14FMG4/G AV-14FMG4/S AV-14FMT4/G

---

Contents

FLOF (Fastext)
WST (World Standard Text)

RM-C1260-2H

(AA/R06/UM-3 battery × 2)

Design & specifications are subject to change without notice.

1-2 (No.YA148)

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 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 10kΩ

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.

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 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 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 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.).

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

0.15 F AC-TYPE

PLACE THIS PROBE

1500 10W

GOOD EARTH GROUND

ON EACH EXPOSED
ME TAL PAR T

(No.YA148)1-3

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

2.1 FEATURES

• New chassis design enables use of an interactive on-screen control.

• Pure flat CRT produces fine textured picture in every detail.

• Wide range voltage (110V ~ 240V) for AC power input.

• With AUDIO/VIDEO input terminals.

2

C bus control utilizes single chip ICs.

•I

• By means of AUTO PROGRAM, the TV stations can be selected automatically and the TV channels can also be rearranged
automatically.

• Built-in OFF TIMER & RETURN +.

2.2 MAIN DIFFERENCE LIST

Items AV-14FMG4/G AV-14FMG4/S AV-14FMT4/G

MAIN PWB ASS'Y SCW-1329A-H2 SCW-1330A-H2 SCW-1327A-H2

FRONT CABINET ASS'Y LC10831-039A-H ← LC10831-040A-H
REMOTE CONTROL UNIT RM-C1261-2H ← RM-C1260-2H

POWER CORD QMPR340-165-K2 QMPR650-165-JC QMPR340-165-K2

1-4 (No.YA148)

2.3 FUNCTIONS

 REMOTE CONTROL UNIT

RM-C1261-2H [AV-14FMG4/G, AV-14FMG4/S]

1

2

11

3

4

5

12

6

7
8

9

13

14

15

16

10

17

SOUND SYSTEM key

1

COLOUR SYSTEM key

2

FAVORITE CHANNEL keys

3

TV / VIDEO key

4

PICTURE MODE key

5

Not used

6

OFF TIMER key

7

RETURN + key

8

DISPLAY / BACK key

9

CHANNEL (-/+) keys

10

POWER key

11

Number keys

12

-/-- key

13

14

MENU(OK) key

15

MENU ( / , / ) keys

16

MUTING key

17

VOLUME (-/+) keys

RM-C1260-2H [AV-14FMT4/G]

1

2

3

4

5

6

7

8

9

10
11

17)

12
13
14
15
16

17

18

19

20

21

22

23
24
25
26

SOUND SYSTEM key

1

COLOUR SYSTEM key

2

FAVORITE CHANNEL keys

3

DISPLAY BACK key

4

MENU ( / , / ) keys

5

TEXT key

6

7

MENU (OK) key

8

PICTURE MODE key

9

OFF TIMER key

RETURN + key

10

CHANNEL (-/+) keys

11

INDEX key

12

MODE key

13

REVEAL key

14

Not used

15

16

STORE key

POWER key

17

18

TV / VIDEO key

19

MUTING key

20

Number keys

-/-- key

21

22

VOLUME (-/+) keys

HOLD key

23

SUB PAGE key

24

25

CANCEL key

SIZE key

26

(No.YA148)1-5

 FRONT PANEL CONTROLS

 REAR TERMINAL

VIDEO AUDIO

IN (VIDEO-2)

1

HEADPHONE jack

1

IN (VIDEO-2) : VIDEO

2

IN (VIDEO-2) : AUDIO

3

MENU (OK) button

4

CHANNEL (-/+) buttons

5

3

2

3

MENU

OK

4

5

6

7

6

VOLUME (-/+) buttons

7

Remote control sensor

8

TIMER lamp

9

POWER lamp

10

MAIN POWER button

8

9

10

VIDEO-1 INPUT TERMINAL

VIDEO-1

INPUT

1 2 4

OUTPUT

VIDEO

AUDIO

VIDEO

1

AUDIO

2

OUTPUT TERMINAL

VIDEO

3

4

AUDIO

5

Aerial input terminal

5

1-6 (No.YA148)

2.4 MAIN CPU [MAIN PWB : IC701] PIN FUNCTION

Pin
no.

1VssP2 -GND
2 VssC4 - GND
3 V1.8C4 I 1.8V (Digital)
4 V3.3A3 I 3.3V
5 VrefP_Sdac I 3.3V (Positive)
6 VrefN_Sdac - GND
7 VrefP_Sdac I 3.3V (Negative)
8 VrefN_Sdac - GND

9 VrefP_Sdac I 3.3V (Positive)
10 XtalIn I 24.576MHz for system clock
11 XtalOut O 24.576MHz for system clock
12 VssA1 - GND
13 NECK I V-guard input/ I/O switch
14 CONT I 1.8V regulator control
15 V5P1 I +5V
16 Ph2 - Phase-2 filter
17 Ph1 - Phase-1 filter
18 Gnd1 - GND
19 SecPll - SECAM PLL decoupling
20 Dec8G - Bandgap decoupling
21 EW O East-West drive output
22 VDRB- O Vertical drive B output
23 VDRA+ O Vertical drive A output
24 Vif1 I Video IF input 1
25 Vif2 I Video IF input 2
26 Vsc - Vertical sawtooth capacitor
27 Iref I Reference current input
28 GndIF - GND
29 Sif1 I Sound IF input 1
30 Sif2 I Sound IF input 2
31 AGC O Tuner AGC output
32 EHT I EHT/overvoltage protection input
33

34 L3 I Audio-L3 input (left signal)
35 R3 I Audio-R3 input (right signal)
36 L-OUT O Audio L output
37 R-OUT O Audio R output
38 DecsDem - Decoupling sound demodulator
39

40 Gnd2 - GND
41 PllIf - IF-PLL loop filter
42 SifAgc - AGC sound IF
43 IfVo/FmRo/DvbO O Not used
44 NC O Not used
45 V8AudioSwitches I 8V
46 AgcSsif - AGC capacitor second sound IF
47 V5P2 I 5V
48 V-OUT O Video output
49 L1 I Audio-L1 input
50 R1 I Audio-R1 input
51 V3 I Video V3 input
52 C4 I Not used
53 Audio2InL I Not used
54 Audio2InR I Not used
55 V2/Y I Video V2 input
56 L2 I Audio L2 input (Left signal)
57 R2 I Audio R2 input (right signal)
58 Y3/Cvbs I S-Video Y1 input
59 C1 I S-Video C1 input
60 AudioLsL O
61 AudioLsR O
62 HP-L O Headphone L
63 HP-R O Headphone R

Pin name I/O Function

Ssif/RefIn/Avl/RefOut

QssO/AmO/AudeEm

O

Automatic Volume Levelling/ sound IF input /
subcarrier reference output / external reference
signal input for I signal mixer for DVB operation

O QSS intercarrier output / AM output /

deemphasis / (front-end audio out)

Audio L output for audio power amplifier
Audio R output for audio power amplifier

Pin
no.

64 CVBSO/PIP O CVBS / PIP output
65 SVM O Scan velocity modulation output
66 FbiSo I Flyback input/sandcastle output
67 Hout O Horizontal output
68 VssComb - GND
69 V5Comb I 5V
70 Vin/R2/Pr I PIP R input
71 Uin/B2/Pb I PIP B input
72 Yin/G2/Y I PIP G input
73 Ysync I Not used
74 Yout O Not used
75 Uout/INSSW2 I YUV insertion input
76 NC O Not used
77 INSSW3 I YUV insertion input
78 R3/Pr I Component PR input (Video-2)
79 G3/Y I Component Y input (Video-2)
80 B3/Pb I Component PB input (Video-2)
81 Gnd3 - GND
82 V5P3 I 5V
83 BCL I Beam current limiter input
84 BLKIN I Black current input
85 Rout O R output
86 Gout O G output
87 Bout O B output
88 V3.3A1 I 3.3V
89 RefAdN - GND
90 V3.3RefAdP I 3.3V (Positive)
91 RefAd I 3.3/2V
92 GndA - GND
93 V1.8A I 1.8V
94 V3.3A2 I 3.3V
95 VssADC - GND
96 V1.8ADC I 1.8V
97 REMOTE I Remote control
98 PW_LED I POWER LED control

99 P11/TO I POWER LED control
100 V1.8C2 I 1.8V
101 VssC2 - GND
102
103
104 VER_PROTECT O X-ray protect
105 S_REDUCE O Sound control
106 P00/I2SDI1 O Not used
107 POWER O SUB POWER control
108 SCL1 I I2C bus clock
109 SDA1 I/O I2C bus data
110 V3.3P I 3.3V
111 ROTATION O ROTATION
112 3.58/OTHER O NTSC 3.58 detection
113 A_MUTE O Audio muting
114 4.5/OTHER O NTSC 4.43 detection
115 PROT I Protect
116 ECO_IN I ECO sensor level detection
117 V1.8C1 I 1.8V (Digital)
118 DecV1V8 I 1.8V
119 KEY_IN I Key scan data
120 VDO-DET I Video DET input
121 VSSC1+P1 - Digital GND
122 P24/PWM3 I S-Video DET input
123 P25/PWM4 O GTVA_reset
124 V1.8C3 I 1.8V (Digital)
125 VssC3 - GND
126 P12/Int2 I External interrupt
127 SDA0 I/O I2C bus data (for memory)
128 SCL0 I I2C bus clock (for memory)

Pin name I/O Function

COMPONENT-PIP
COMB_SW_NT3.5/OTHER

- Not used

- Not used

(No.YA148)1-7

SECTION 3

DISASSEMBLY

3.1 DISASSEMBLY PROCEDURE

3.1.1 REMOVING THE REAR COVER

• Unplug the power cord.
(1) Remove the 4 screws [A], 1 screw [B] and 2 screws [C] as

shown in Fig.1.

(2) Withdraw the REAR COVER toward you.

CAUTION:

When reinstalling the rear cover, carefully push it inward after
inserting the MAIN PWB into the REAR COVER groove.

3.1.2 REMOVING THE MAIN PW BOARD

• Remove the REAR COVER.
(1) Slightly raise the both sides of the MAIN PWB by hand.
(2) Withdraw the MAIN PWB backward.

(If necessary, take off the wire clamp and connectors, etc.)

3.1.3 REMOVING THE SPEAKER

• Remove the REAR COVER.
(1) Remove the 2 screws [D] as shown in Fig.1.
(2) Follow the same steps when removing the other hand

SPEAKER.

3.1.4 CHECKING THE MAIN PW BOARD

• 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.

CAUTIONS:

• 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.

• When repairing, connect the DEG. COIL to the DEG.

connector on the MAIN PWB.

3.1.5 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.

1-8 (No.YA148)

PICTURE TUBE

FRONT CABINET

SPEAKER

MAIN PWB
(CRT SOCKET PWB)

D

(x2)

FBT

SPEAKER

MAIN PWB

D

(x2)

REAR COVER

A

(x4)

B

Fig.1

C

(x2)

(No.YA148)1-9