JVC AV-14A14/A, AV-14A14/H, AV-14AG14/U, AV-14AMG4/G, AV-14AMG4/S Service Manual

SERVICE MANUAL

COLOUR TELEVISION

AV-14A14/A, AV-14A14/H,

AV-14AG14/U, AV-14AMG4/G,

AV-14AMG4/S

BASIC CHASSIS

CW

TABLE OF CONTENTS

1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7 4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13 5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-28

COPYRIGHT © 2004 Victor Company of Japan, Limited

No.YA150

2004/12

SPECIFICATION

						Contents
Items								AV-14AG14/U
				AV-14A14/A		AV-14A14/H		AV-14AMG4/G
								AV-14AMG4/S
Dimensions (W × H × D)				36.4cm × 33.35cm × 37.4cm
Mass				9kg
TV RF System				B, G, I, D, K				B, G, I, D, K, M
Colour System			TV Mode	PAL / SECAM				PAL / SECAM / NTSC3.58 /
								NTSC4.43
		Video Mode		PAL / SECAM / NTSC3.58 / NTSC4.43				PAL / SECAM / NTSC3.58 /
								NTSC4.43
Receiving Frequency			VHF Low	46.25MHz ~ 168.25MHz (AU0 ~ S10)
		VHF High		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
Intermediate			VIF	38.0MHz
Frequency
			SIF	D/K: 31.5MHz (6.5MHz)				D/K: 31.5MHz (6.5MHz)
				I: 32.0MHz (6.0MHz)				I: 32.0MHz (6.0MHz)
				B/G: 32.5MHz (5.5MHz)				B/G: 32.5MHz (5.5MHz)
								M: 33.5MHz (4.5MHz)
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.)		50W, 0.4A		65W (Max.) / 48W (Avg.)
Picture Tube				A34JXV70X
				14-inch, aspect ratio 4:3, conventional square face type, tinted
Screen Size				Visible size : 34.0cm (Diagonal) / 28.7cm × 21.7cm (H ×			V)
High Voltage				22.5kV±1.5kV (at zero beam current)
Speaker				8cm, round type × 1
Audio Output				3W
Video / Audio Input		Video [1/2]		1V(p-p), negative sync, 75Ω , RCA pin jack × 2
[1/2]		Audio [1/2]		500mV(rms) (-4dBs ), high impedance, RCA pin jack ×			2
Video / Audio Output			Video	1V(p-p), 75Ω , RCA pin jack ×		1
			Audio	500mV(rms)(-4dBs), Low impedance (400Hz when modulated 100%), RCA pin jack × 1
Headphone				3.5mm stereo mini jack ×	1
Remote Control Unit				RM-C1261-2H
				(AA/R06/UM-3 battery ×	2)

Design & specifications are subject to change without notice.

1-2 (No.YA150)

SECTION 1 PRECAUTION

1.1SAFETY 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	ON EACH EXPOSED
			METAL PART

GOOD EARTH GROUND

(No.YA150)1-3

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

2.1FEATURES

•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.

•I2C bus control utilizes single chip ICs.

•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 +.

2.2MAIN DIFFERENCE LIST

	Items	AV-14A14/A	AV-14A14/H		AV-14AG14/U
	POWER CONSUMPTION	65W (Max.) / 48W (Avg.)	50W, 0.4A	65W (Max.) / 48W (Avg.)
	PLUG TYPE

	Items		AV-14AMG4/G				AV-14AMG4/S
	POWER CONSUMPTION	65W (Max.) / 48W (Avg.)					←
	PLUG TYPE

2.3FUNCTIONS

REMOTE CONTROL UNIT

RM-C1261-2H
1
2	11	1	SOUND SYSTEM key	12	Number keys
3		2	COLOUR SYSTEM key	13	-/-- key
4		3	FAVORITE CHANNEL keys	14	MENU(OK) key
5		4	TV / VIDEO key	15	MENU ( / , / ) keys
	12	5	PICTURE MODE key	16	MUTING key
6
7	13	6	Not used	17	VOLUME (-/+) keys
8	14	7	OFF TIMER key
9	15	8	RETURN + key
	16	9	DISPLAY / BACK key
10	17	10	CHANNEL (-/+) keys
		11	POWER key
1-4 (No.YA150)

FRONT PANEL CONTROLS

	VIDEO	AUDIO
	IN (VIDEO-2)
			MENU	CHANNEL	VOLUME
			OK
1	2	3	4	5	6	7	8	9
1	HEADPHONE jack				6	VOLUME (-/+) buttons
2	IN (VIDEO-2) : VIDEO				7	Remote control sensor
3	IN (VIDEO-2) : AUDIO				8	POWER lamp
4	MENU (OK) button				9	MAIN POWER button
5	CHANNEL (-/+) buttons

REAR TERMINAL

3	VIDEO-1 INPUT TERMINAL

1 VIDEO

2 AUDIO

	VIDEO-1	OUTPUT	OUTPUT TERMINAL
	INPUT

3 VIDEO

4 AUDIO

VIDEO

AUDIO

5 Aerial input terminal

1

2

4

5

(No.YA150)1-5

2.4MAIN CPU [MAIN PWB : IC701] PIN FUNCTION

	Pin	Pin name	I/O	Function
	no.
	1	VssP2	-	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	Ssif/RefIn/Avl/RefOut	O	Automatic Volume Levelling/ sound IF input /
				subcarrier reference output / external reference
				signal input for I signal mixer for DVB operation
	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	QssO/AmO/AudeEm	O	QSS intercarrier output / AM output /
				deemphasis / (front-end audio out)
	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	Audio L output for audio power amplifier
	61	AudioLsR	O	Audio R output for audio power amplifier
	62	HP-L	O	Headphone L
	63	HP-R	O	Headphone R

	Pin	Pin name	I/O	Function
	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	COMPONENT-PIP	-	Not used
	103	COMB_SW_NT3.5/OTHER	-	Not used
	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)

1-6 (No.YA150)

SECTION 3

DISASSEMBLY

3.1DISASSEMBLY PROCEDURE

3.1.1 REMOVING THE REAR COVER

•Unplug the power cord.

(1)Remove the 4 screws [A], 2 screws [B] and 1 screw [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.

3.1.2REMOVING 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.)

3.1.3REMOVING THE SPEAKER

•Remove the REAR COVER.

•Remove the MAIN PW BOARD.

(1)Raise the SPEAKER HOLDER claw [D] slightly, and remove the SPEAKER HOLDER.

(2)Remove the 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.

(No.YA150)1-7

PICTURE TUBE

FRONT CABINET

MAIN PWB

(CRT SOCKET PWB)

SPEAKER

SPEAKER HOLDER

FBT

MAIN PWB

REAR COVER

C

B (x2)

A (x4)

Fig.1

1-8 (No.YA150)

3.2REPLACEMENT OF MEMORY IC

3.2.1 MEMORY IC

This TV uses the following memory IC.

Memory IC: IC702 on MAIN PWB

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".

3.2.2 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 Table 1.

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 Table 3. 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 4.) If readjustment is necessary, perform adjustment referring to "ADJUSTMENTS PROCEDURE".

NAME OF REMOTE CONTROL KEYS

PICTURE MODE
	MENU OK
DISPLAY / BACK	MENU
MENU	MENU
	MENU

SERVICE MENU

SERVICE MENU

1. IF	2. V/C
3. AUDIO	4. DEF
5. VSM W/B	6. S TATUS
7. PLUG & PLAY (ON)
1-7 : SELECT	DISPLAY : EXIT

******* **** ***** *****

******** *** ***

Fig.1

SYSTEM CONSTANT-1

SYSTEM CONSTANT SET 1

SYSTEM	TRIPLE
COMB	NO
TILT	NO
SUPER BASS	NO
TEXT	NO
LANGUAGE	ERCMI
: SEL : OPE	DISP : EXIT

SYSTEM CONSTANT-2

SYSTEM CONSTANT SET 2

SOUND	MONO
BILINGUAL	NO
BLUE BACK MUTE	NO
COLOUR AUTO	NO
ECO SENSOR	NO
: SEL : OPE	DISP : EXIT

SYSTEM CONSTANT-3

SYSTEM CONSTANT SET 3

SURROUND	NO
PICTURE BOOSTER	NO
COMPONENT	NO
PIP	NO
S INPUT	NO
: SEL : OPE	DISP : EXIT

Fig.2

(No.YA150)1-9