JVC AV-48WP74/AHA User manual

SERVICE MANUAL
COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LTD. No.52105B
2003/6
REAR PROJECTION TELEVISION
52105B20036AV-48WP74/AHA,
AV-56WP74/AHA
The following items for the AV-48WP74/AHA and AV-56WP74/AHA model were changed partly from AV-
48WP74/HA and AV-56WP74/HA model.
Therefore, this service manual describes only the items which differ from those of the AV-48WP74/HA and
AV-56WP74/HA model service manual.
For details other than those described in this manual, please refer to the AV-48WP74/HA and AV-56WP74/
HA model service manual (No.52105, 2003/04).
OUTLINE
HOW TO IDENTIFY MODELS
Since the mirror was changed, we have issued the SERVICE MANUAL for AV-48WP74/AHA and AV-56WP74/
AHA.
MODEL
A suffix “AHA” is added to the serial No. after at the rating label.
Indicated
SERIAL No. “AHA”
AV-48WP74
AV-56WP74
BASIC CHASSIS
SB3
Supplementary

(No.52105B)
AV & MULTIMEDIA COMPANY VIDEO DISPLAY CATEGORY 12, 3-chome, Moriya-cho, kanagawa-ku, Yokohama, kanagawa-prefecture, 221-8528, Japan
VICTOR COMPANY OF JAPAN, LIMITED
Printed in Japan
WPC
DIFFERENCE LIST
EXPLODED VIEW PARTS LIST -1 (Page 3-2)
EXPLODED VIEW -1
Ref. No. PARTS No. PARTS NAME DESCRIPTION
AV-48WP74/HA AV-48WP74/AHA
4 QYSBSF4012Z ------------ TAP SCREW (X2) Delete
5 LC31752-001A-A ------------ MIRROR BRACKET (X2) Delete
23 LC31733-001A-A LC32173-003A-A MIRROR Glass
70 ------------ QYSBSF4012Z TAP SCREW (X13) Addition
71 ------------ LC21316-001A-A MIRROR HOLDER TOP Addition
72 ------------ LC21317-001A-A MIRROR HOLDER BOTTOM Addition
73 ------------ LC21311-001B-A MIRROR HOLDERLEFT Addition
74 ------------ LC21311-002B-A MIRROR HOLDER RIGHT Addition
Ref. No. PARTS No. PARTS NAME DESCRIPTION
AV-56WP74/HA AV-56WP74/AHA
4 QYSBSF4012Z ------------ TAP SCREW (X2) Delete
5 LC41419-001A-A ------------ MIRROR BRACKET (X2) Delete
6 QYSBSF4012Z ------------ TAP SCREW (X2) Delete
23 LC31954-001A-A LC32173-002A-A MIRROR Glass
70 ------------ QYSBSF4012Z TAP SCREW (X13) Addition
71 ------------ LC21316-001A-A MIRROR HOLDER TOP Addition
72 ------------ LC21317-001A-A MIRROR HOLDER BOTTOM Addition
73 ------------ LC21311-001B-A MIRROR HOLDERLEFT Addition
74 ------------ LC21311-002B-A MIRROR HOLDER RIGHT Addition
23
71
70
70
73
74
72
70

SERVICE MANUAL
COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LTD. No.52105
2003/4
AV-48WP74
AV-56WP74
REAR PROJECTION TELEVISION
5210520034AV-48WP74/HA,
AV-56WP74/HA
TABLE OF CONTENTS
1 PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
3 ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21
4 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-64
BASIC CHASSIS
SB3

AV-48WP74
AV-56WP74
1-2 (No.52105)
SPECIFICATION
Design & specifications are subject to change without notice.
Items Contents
AV-48WP74 AV-56WP74
Dimensions (W x H x D) 120.0cm x 124.4cm x 60.9cm
( 47 1/4" x 49" x 24" ) 136.8cm x 138.6cm x 66.7cm ( 53 7/8" x 54 5/8" x 26 3/8" )
Mass 81kg (179 Ibs) 95kg (209 Ibs)
TV RF System
Color System
Sound System
CCIR (M)
NTSC
BTSC System (Multi Channel Sound)
TV Receiving Channels and
Frequency VL Band
VH Band
UHF Band
(02~06) 54MHz~88MHz
(07~13) 174MHz~216MHz
(14~69) 470MHz~806MHz
CATV Receiving Channels and
Frequency Low Band
High Band
Mid Band
Super Band
Hyper Band
Ultra Band
Sub Mid Band
54MHz~804MHz
(02~06, A-8) by (02~06 & 01)
(07~13) by (07~13)
(A~1) by (14~22)
(J~W) by (23~36)
(W+1~W+28) by (37~64)
(W+29~W+84) by (65~125)
(A8, A4~A1) by (01, 96~99)
TV/CATV Total Channel 180 Channels
Antenna Terminal (VHF/UHF) 75ohm unbalanced F-type connector
Intermediate Frequency
Video IF Carrier
Sound IF Carrier 45.75MHz 41.25MHz (4.5MHz)
Color Sub Carrier 3.58MHz
Power Input
Power Consumption 120V AC, 60Hz 248W (Max)
Screen Transparent screen (unitized fresnel lens/double lenticular lens)
Screen Size 48" (122cm) Measured diagonally, 16:9 ratio
(W:106.3 cm x H:59.8 cm) 56" (142cm) Measured diagonally, 16:9 ratio (W:124 cm x H:69.8 cm)
Projection Tube
High Voltage 17cm (6.7") tube x 3 ( R/G/B ) 31kV±1.0kV (at zero beam current)
Speaker
Audio Power Output 16cm round x 2 (Woofer), 5.5cm round x 2 (Tweeter) 10W+10W
External Input Video Input
Audio Input
S-Video
Component Input
1V (p-p), 75ohm (RCA pin jack x 4)
500mV(rms) ( -4dBs), high impedance (RCA pin jack x 8)
Y: 1V (p-p) positive, 75ohm negative sync provided
C: 0.286V(p-p) (burst signal)
Mini-DIN 4pin connector x 2
Y: 1V (p-p), 75ohm (RCA pin jack x 2)
Pb: ±0.35V(p-p), 75ohm (RCA pin jack x 2)
Pr: ±0.35V(p-p), 75ohm (RCA pin jack x 2)
1080i DTV (digital broadcast) ready
Digital Input
Audio Input
DVI-D signal link 19pin connector
(Digital-input terminal is not compatible with computer signal)
500mV(rms) ( -4dBs), high impedance (RCA pin jack x 2)
Subwoofer Output More than 0 to 1000mV (rms) (+2.2dBs) (RCA pin jack x1)
Audio Output (VARI/FIX) VARI : More than 0 to 1000mV (rms) (+2.2dBs)
FIX : 500mV(rms) (-4dBs), low impedance (1kHz when modulated 100%)
(RCA pin jack x 2)
Speaker Input 45W 16ohm (maximum input)
AV Compulink lll Ø3.5mm mini jack
Remote Control Unit RM-C1200G (AA/R6/UM-3 battery x 2)

AV-48WP74
AV-56WP74
(No.52105)1-3
SECTION 1
PRECAUTIONS
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 visualinspectionnor canthe protection affordedby them
necessarily be obtained by using replacement components rated for
higher voltage, wattage, etc. Replacement parts that have these
special safety characteristics are identified in the parts list of Service
manual. Electrical components having such features are
identifiedby shading on theschematics 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
replacementpart shown intheparts list ofServicemanualmaycause
shock, fire, or other hazards.
(4) Use isolation transformer when hot chassis.
The chassis and any sub-chassis contained in some products are
connected to one side of the AC power line. An isolation transformer
of adequate capacity should be inserted between the product and the
AC power supply point while performing any service on some
products when the HOT chassis is exposed.
(5) 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 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.
(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-Rayemission, arcingandpossible 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) 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).
(8) 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
10kΩ2W resistor to the anode button.
(9) 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.
(10) 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, screwheads, 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 1100V 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 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 1000 ohms per volt or more sensitivity in
the following manner. Connect a 1500ohm 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.).
(11) High voltage hold down circuit check.
After repair of the high voltage hold down circuit, this circuit shall be
checked to operate correctly.
See item "How to check the high voltage hold down circuit".
AC VOLTMETER
(HAVING 1000 /V,
OR MORE SENSITIVITY)
PLACE THIS PROBE
ON EACH EXPOSED
METAL PART
1500 10W
0.15 F AC-TYPE
GOOD EARTH GROUND
PWB
White line side
WHT
PW
POWER CORD
REPLACEMENT WARNING.
Connecting the white line side of power
cord to "WHT" character side.
A V
This mark shows a fast
operating fuse, the
letters indicated below
show the rating.

AV-48WP74
AV-56WP74
1-4 (No.52105)
1.2 INSTALLATION
1.2.1 INSTALLATION SITE
(1) The rear of this set is provided with ventilation openings.
Install the set more than 5 cm from a wall and in a location
with good ventilation.
(2) Avoid the following types of locations.
a) Unstable locations (location must be able to
withstand heavy weight).
b) Locations subjected to direct sunlight.
c) Near stoves or other heating devices.
d) Locations subjected to humidity or oily smoke.
e) Dusty locations.
f) Locations with strong vibration.
1.2.2 INSTALLATION ADJUSTMENT
When installing, moving or changing the orientation of the set,
perform static convergence adjustment according to the
following procedure.
Adjusting CRT color convergence have two method, AUTO,
MANUAL and RESET. It adjust on the MENU screen.
NOTE :
Please have you TV on for at least 20 minutes before sing this
feature.
This adjustment will be needed only when the colors of the
characters/lines are separated and lack in distinction. If not,
please don't perform the adjustment.
AUTO
(1) Press the [MENU] key, and select the
"CONVERGENCE" in the INITIAL SETUP menu with the
[function up/down] key.
(2) Press the [function left/right] key, then CONVERGENCE
menu appear.
(3) Press the [function up/down] key, and select the
"AUTO".
(4) Press the [function left/right] key.
(5) he convergence adjustment will start. It will take about 50
seconds.
MANUAL
(1) Press the [MENU] key, and select the
"CONVERGENCE" in the INITIAL SETUP menu with
[function up/down] key.
(2) Press the [function left/right] key, the CONVERGENCE
menu appears.
(3) Press the [function up/down] key, and select the
"MANUAL".
(4) Press the [function left/right] key, then CONVERGENCE
adjustment screen appear. [Fig.1]
• If all the crosses are white, no convergence
adjustment is needed.
(5) Select the location you want to adjust by using the
[number (2/4/5/6/8)] keys on the remote control unit.
[Fig.2]
(6) Press the [SELECT] key to change the color of the box
to the color of the cross you want to adjust (red or blue).
• You cannot adjust the green cross.
(7) Use the [function up/down] key and the [function left/
right] keys to adjust the position of the cross.
(8) Adjust the three colors crosses until they overlap and
appear as a single white cross.
(9) Press the [OK] key.
NOTE :
• When you adjust the convergence, make sure you
start with the center position (position 5), and work
your way around radial for best results
• When you make the adjustment in the center
(positions 5), you are making the adjustment for the
whale screen. In other positions, you are making the
adjustment only in that area.
• You can reset the adjustment if you do not like the
results, See below.
• If you perform AUTO CONVERGENCE after
performing MANUAL CONVERGENCE, your
manual convergence you performed will be
cancelled.
(10) Press the [MENU] key to end the convergence
adjustment procedure.
RESET
RESET in the CONVERGENCE menu resets all convergence
adjustments to the factory default setting.
Fig.1
Fig.2
(more than 5cm)
Wall
VENTILATION OPENING
5
2
46
8

AV-48WP74
AV-56WP74
(No.52105)1-5
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
2.1 FEATURES
• New chassis design enable use of an interactive on screen control.
• 2-3 PULL DOWN : You can enjoy DVD movies at the highest picture quality.
• MOTION COMPENSATION : With this function, the seamless reproduction of dynamic motion on the screen has been realized.
• Bullet-in DSD (Digital Supper Detail) circuit and 3 dimension Y/C separate circuit.
• Receive DTV broadcast (1080i / 720p / 480p / 480i)
• Built-in HDCP / Component (Y / Pb / Pr) input.
• Built-in Hyper Sound, BBE circuit.
2.2 FUNCTIONS
S-VIDEO
S-VIDEO
VIDEO
VIDEO
OPERATE
OPERATE
L / MONO
/ MONO
R
INPUT4
SUPER
SUPER
FOCUS
FOCUS
AUDIO OUTSUBWOOFER
OUT
DIGITAL IN
INPUT-3
INPUT-2
INPUT-1
RL
AUDIO VIDEO S-VIDEO
RL
AUDIO
RL
OVER
OVER
INPUT-2
Y
P
b
P r
Y
P
b
P r
INPUT-1
COMPONENT VIDEO
AV COMPULINK
SPEAKER INPUT
16 45W MAX
1
2
9
8
7
3
3
4
5
4
1
10
6
5
2
FRONT CONTROL KEY & TERMINAL
REAR TERMINAL
MENU Button ( OPERATE )
1
CHANNERL -/+ Button ( OPERATE / )
2
SPEAKER INPUT
7
SUBWOOFER / AUDIO OUT
8
AV COMPULINK
9
AUDIO INPUT (For DIGITAL IN)
10
VOLUME -/+ Button
3
MAIN POWER Button
4
POWER LED (Blue)
5
INPUT4
( AUDIO / VIDEO / S-VIDEO )
6
DIGITAL IN
( DVI-D Signal Link 19pin )
1
INPUT 1
( AUDIO / VIDEO / S-VIDEO )
2
INPUT 2
( AUDIO / VIDEO / S-VIDEO )
3
INPUT 3
( AUDIO / VIDEO )
4
COMPONENT VIDEO INPUT 1
( Y / Pb / Pr )
5
COMPONENT VIDEO INPUT 2
( Y / Pb / Pr )
6
6

AV-48WP74
AV-56WP74
1-6 (No.52105)
RM-C1200G
POWER
VIDEO
STATUS
INPUT2
INPUT3
INPUT4
DIGITAL-IN
INPUT1
SPLIT
100+
3
9
6
RETURN+
/TV
MUTING
MENU
C.C.
BACK
TV
CATV VCR DVD
THEATER
PRO NATURAL
CINEMA
LIGHT
SLEEP TIMER DISPLAY SOUND
1
7
4
2
8
0
5
3
9
6
POP
FREEZE SWAP SELECT
INDEX
ASPECT
EZ SURF
+
CH
VOL VOL
+
CH
OK
REC
OPEN/CLOSE STILL/PAUSE
STOP PAUSE
PLAY FFREW
VCR CHANNEL
PREV NEXT
TV/VCR
VCR/DVD
POWER
MULTI SCREEN
14
5
7
9
11
10
6
8
14
12
13
23
15
16 17
19
18
20
22
23
21
REMOTE CONTROL UNIT [RM-C1200G]
POWER Key
1
ASPECT Key
2
VCR / DVD Switch
3
TV / CATV Switch
4
Input select Keys
5
THEATER PRO Key
6
SLEEP TIMER Key
7
DISPLAY Key
8
MUTING Key (memory Key)
9
Function up / down / right / left Keys
(CH + / CH - / VOL + / VOL - Keys)
10
MENU Key
11
MULTI SCREEN operation Keys
12
Number (1~0)Keys
13
100+ Key
14
RETURN+ / TV Key
15
VIDEO STATUS Key
16
NATURAL CINEMA Key
17
LIGHT Key
18
SOUND Key
19
C.C.(Closed Caption) Key
20
OK Key
21
BACK Key
22
VCR / DVD operation Keys
23

AV-48WP74
AV-56WP74
(No.52105)1-7
DIGITAL-IN TERMINAL FUNCTIONS
PIN ASSIGNMENT
1 RX2-
Pin
No. Pin name
2 RX2+
3 GND2/ 4
4 RX4-
5 RX4+
6 SCL
7 SDA
8NC
9 RX1-
10 RX1+
11 GND1/3
12 RX3-
13 RX3+
Pin
No. Pin name
14 5V
15 GND
16 HTPLG
17 RX0-
18 RX0+
19 GND0/5
20 RX5-
21 RX5+
22 GNDC
23 TXC+
24 TXC-
2
3
6
7
8
1
9
10
11
12
13
14
15
16
4
5
18
19
20
21
22
23
24
17

AV-48WP74
AV-56WP74
1-8 (No.52105)
2.3 TECHNICAL INFORMATION
2.3.1 MAIN MICRO COMPUTER (CPU) FUNCTION (MN102H75K)
Pin No. Pin name I/O Function
1 NC - --------
2 /MICON_V I V.sync for OSD
3 LB_PRO I Low B protection detection
4 NC - --------
5 /RST I Main cpu reset input
6 NC - --------
7 /TEST I +3.3V
8 OSD_YS O OSD Ys output
9 NC - --------
10 NC - --------
11 A_MU O Audio muting
12 /MICON_H I H sync input
13 M_MU O Monitor sound out muting
14 P46,OSDXI - Keep for OSD
15 P45,OSDXO - Keep for OSD
16 SDA2 I/O I2C bus (CLK) for MTS
17 AC_IN I AC (60Hz) input
18 SCL2 O I2C bus (DATA) for MTS
19 TU_POW O Tuner power control
20 VCOI I LPF input
21 PDO O LPF output
22 /IP_RESET O Reset
23 OSD_YM O OSD YM output
24 OSD_B O OSD blue output
25 POWER_LED O Lighting for POWER LED
26 OSD_G O OSD green output
27 OSD_R O OSD red output
28 VREF I --------
29 IP_ERR I AMDP program load detect.
30 IREF I --------
31 COMP I --------
32 AVDD I +3.3V
33 CLL I For sub CCD
34 VREFLS I STD VOL for sub CCD
35 SUB_CCD I For sub CCD
36 NC - --------
37 VSS I GND
38 MAIN_CCD I For main CCD
39 VREFHS I STD VOL for main CCD
40 CLH I For main CCD
41 VDD/VPP O +3.3V
42 CLK SW1 O IP clock switch
43 CLK SW2 O IP clock switch
44 ON_TIM O Lighting for ON TIMER
45 CONVER_RXD O Convergence control
46 CONVER TXD I Convergence control
47 SBT1 I --------
48 NC - --------
49 NC - --------
50 NC - --------
51 NC - --------
52 EE_ABL O ACL control
53 CHROMA O Chroma / gamma control
54 DC_COTL O DC, control
55 NC - --------
56 NC - --------
57 TU2_AID I Main AFC input
58 /LOB_POW O Low B power control
59 COMPULINK I AV COMPULINK lll input
60 /POWERGOOD I Power condition check
61 MECA_ON I Machine SW interrupt
62 /MAIN_POW O Main power control
63 NC - --------
64 /B1 POW O B1 power control
65 C/N I AFC voltage input
66 X_RAY I X-ray protection detection
67 NC - --------
68 KEY2 I Front key input 2
69 KEY1 I Front key input 1
70 SCL1 O I2C bus (CLK) for EEP-ROM
71 SDA1 I/O I2C bus (SDA) for EEP-ROM
72 REMO I Remote control input
73 NC - --------
74 VSS I GND
75 OSC2 O 4MHz clock oscillation
76 OSC1 I 4MHz clock oscillation
77 VDD I +3.3V
78 SCL0 O I2C bus (CLK) for general
79 AP_CLK - --------
80 SDA0 I/O I2C bus (SDA) for general
81 NC - --------
82 NC - --------
83 NC - --------
84 P_MU O Picture muting
Pin No. Pin name I/O Function

AV-48WP74
AV-56WP74
(No.52105)1-9
2.4 MAIN PARTS LOCATION
2.4.1 PWB ASS'Y ARRANGEMENT
The PWB ASS'Y is indicated below.
PWB ASS’Y NAME AV-48WP74 AV-56WP74
MAIN PWB ASS'Y SSB-1070A-M2 SSB-1069A-M2
RECEIVER PWB ASS'Y SSB0R368A-M2 SSB0R368A-M2
MI-COM & DIST MODULE PWB ASS'Y SSB0D070A-M2 SSB0D069A-M2
POWER & DEF PWB ASS'Y SSB-2070A-M2 SSB-2069A-M2
DEF OSC PWB ASS'Y SSB0H068A-M2 SSB0H068A-M2
LINE FILTER PWB ASS'Y SSB-9068A-M2 SSB-9068A-M2
FRONT RELAY PWB ASS'Y SSB0L268A-M2 SSB0L268A-M2
CONVERGENCE OUT PWB ASS'Y SSB-5068A-M2 SSB-5068A-M2
DIGITAL CONVERGENCE MODULE PWB ASS'Y SSB0K070A-M2 SSB0K069A-M2
DIGITAL INPUT MODULE PWB ASS'Y -------- --------
REMOCON SENSOR PWB ASS'Y SSB-8068A-M2 SSB-8068A-M2
R CRT SOCKET PWB ASS'Y SSB-3168A-M2 SSB-3168A-M2
G CRT SOCKET PWB ASS'Y SSB-3268A-M2 SSB-3268A-M2
B CRT SOCKET PWB ASS'Y SSB-3368A-M2 SSB-3368A-M2
G VM PWB ASS'Y SSB-7268A-M2 SSB-7268A-M2
FRONT CONTROL PWB ASS'Y SSB0L068A-M2 SSB0L068A-M2
FRONT CONTROL ASS'Y PROJECTION UNIT
REMOCON SENSOR
PWB
FRONT CONTROL
PWB
CRT SOCKET
PWB (R/G/B) VM PWB (G only)
DIGITAL INPUT
MODULE PWB
AV TERMANEL BOARD
(This figure is only MAIN UNIT)
DEF OSC
PWB
POWER & DEF
PWB
MAIN PWB
RECEIVER PWB
LINE FILTER
PWB
MI-COM & DIST
MODULE PWB
FRONT RELAY
PWB
CONVERGENCE OUT
PWB
DIGITAL CONVERGENCE
MODULE PWB

AV-48WP74
AV-56WP74
1-10 (No.52105)
2.5 SCREEN HANDLING CAUTIONS
2.5.1 SCREEN STORAGE
Store the SCREEN ASS'Y in a standing position in order to avoid deformation. If the screen is stored horizontally, there is risk of
deforming the screen face.
When necessary to place the SCREEN ASS'Y horizontally, position the screen side upwards and sure to place spacers between the
screen and resting site (floor or stand etc.) to prevent the screen from sagging.
2.5.2 SCREEN SURFACE
Since the screen surface is easily scratched or soiled, use ample care when handling.
2.6 PROJECTION UNIT REPLACEMENT
2.6.1 ADJUSTMENT DURING REPLACEMENT
When replacing the three R, G and B projection units, first replace the R and B units and perform focus / screen / raster centering
adjustments with reference to the G unit. Then replace the G unit and perform G focus / screen / convergence adjustment. Finally
perform R & B convergence adjustments. Use care to simultaneously removes all three-projection units.
2.6.2 DISASSEMBLY CAUTION
The projection units include locations that are not to be disassembled during service. When replacing projection unit parts,
disassemble to the state indicated in the figure below.
The figure indicates screws and wires that are not to be removed. Use care not to remove these.
SCREEN BRACKET
(TOP)
SCREEN BRACKET
(RIGHT)
SCREEN BRACKET
(BOTTOM)
Leave the screen with protector fresnel
lens and double lenticular lens attached.
If cannot be disassembled further.
SCREEN BRACKET
(LEFT)
SENSOR
SCREEN
FRONT CABINET
SENSOR
SENSOR
SENSOR
A( x 5)
A( x 5)
A( x 7)
A( x 7)
DISASSEMBLY PROCEDURE
If the screen or screen panel need to
be replaced, remove the 24 screws A.
LENS ASS'Y SCREW ( x 4)
LENS ASS'Y
CRTASS'Y (COUPLER ASS'Y)
DEF. / CONVER. YOKE
VM PWB (G only)
PC MAGNET
PC MAGNET
TAPE
R CRT SOCKET PWB ASS'Y
G CRT SOCKET PWB ASS'Y
B CRT SOCKET PWB ASS'Y
Check that tape is applied to the CRT neck.
If absent, the deflection yoke can dislodge.
Deflection yoke wires : to connector on POWER & DEF. PWBASS'Y.
[R="RHV", G="GHV", B="BHV"]
Convergence yoke wires : to connector on CONVERGENCE PWB ASS'Y.
[R="R", G="G", B="B"]
Do not remove screws
Do not disassembly
ANODE wires : to DIVIDER

AV-48WP74
AV-56WP74
(No.52105)1-11
2.7 DISASSEMBLY PROCEDURE
• Make sure that the power cord is pulled out from the AC outlet.
2.7.1 SPEAKER GRILLE
(1) Remove 4 screws [ A ] from rear side.
(2) Open the door of the FRONT CONTROL BOX and remove
2 screws [ B ] from front side.
(3) Take out the SPEAKER GRILLE.
2.7.2 SPEAKER (WOOFER)
• Take out the SPEAKER GRILLE
(1) Remove 4 screws [ C ].
(2) Take out the WOOFER.
(3) Disconnect the speaker wire from speaker terminal.
*Remove the both side speaker same manner.
2.7.3 SPEAKER (TWEETER)
• Take out the SPEAKER GRILLE
(1) Remove 2 screws [ D ].
(2) Take out the TWEETER.
(3) Disconnect the speaker wire from speaker terminal.
*Remove the both side speaker same manner.
2.7.4 FRONT BOARD
• Take out the SPEAKER GRILLE.
(1) Remove 4 screws [ E ].
(2) Take out the FRONT BOARD.
2.7.5 FRONT CONTROL BOX
• Take out the SPEAKER GRILLE.
(1) Remove 4 screws [ F ] attaching the FRONT CONTROL
BOX.
(2) Disconnect the connector [BH], [R], [BG] on the FRONT
CONTROL PWB.
(3) Take out the FRONT CONTROL BOX.
2.7.6 FRONT CONTROL PWB
• Take out the SPEAKER GRILLE.
• Take out the FRONT CONTROL BOX.
(1) Remove 3 screws [ G ] from rear side of FRONT
CONTROL BOX.
(2) Take out the FRONT CONTROL PWB.
Fig.1
Fig.2
C
A
SPEAKER
(TWEETER)
SPEAKER
(WOOFER)
SPEAKER WIRE
D
F
E
B
A
FRONT CONTROL
BOX
FRONT BOARD
SPEAKER GRILL
G
BH BGR
FRONT CONTROL BOX
REAR SIDE FRONT CONTROL PWB
CAUTION AT DISASSEMBLY
1
3
5
2
4
6
56WP74CP-S : DIGITAL INPUT MODULE [AV-56WP74]
48WP74CP-S : DIGITAL INPUT MODULE [AV-48WP74]
POWER CORD
SB
connector
AV JACK BOARD
Prior to disassembly, unplug the power code from the AC outlet
without fail. (Turn the power "off".)
Short the SB connector [1] pin and [2] pin of the DIGITAL INPUT
MODULE. (At the time of assembling)
Before the rear panel is inserted into the cabinet, release the
short-circuit between the SB connector [1] pin and [2] pin of the
DIGITAL INPUT MODULE.
After releasing the short-circuit between the SB connectors, do
not turn the power on until the rear panel is inserted into the
cabinet.
Negligence in carrying out the above steps may cause the
inactivation of the TV.

AV-48WP74
AV-56WP74
1-12 (No.52105)
2.7.7 SCREEN ASS'Y
• Take out the SPEAKER GRILLE.
• Take out the FRONT CONTROL BOX.
(1) Remove the 2 screws [ H ] under the SCREEN ASS'Y from
front side.
(2) Remove 10 screws [ I ] from rear side.
(3) Take out the connector [ CN00Z ].
(4) Take out the SCREEN ASS'Y.
NOTE :
• Please place the SCREEN ASS'Y on a flat table without
fail.
• Because of the large size, at least two parsons are
recommended for removal and reassemble.
• Use core not to scratch the screen during work.
• During assembly, be sure to engage the left and right tabs
with the cabinet mounting positions.
• When supporting the SCREEN ASS'Y, grasp the both
sides of the screen panel instead of the upper side of the
screen panel.
Fig.3
2.7.8 MIRROR
• Take out the SPEAKER GRILLE.
• Take out the FRONT CONTROL BOX.
• Take out the SCREEN ASS'Y.
(1) Remove 2 screws [ J ] attaching the mirror stopper.
(2) Raise slightly to disengage of the mirror from the hooks.
(3) Take out the MIRROR.
NOTE :
• The MIRROR is front-coated. Do not touch the front of the
MIRROR.
• At least 2 persons are recommended for removable and
reassemble.
Fig.4
SCREEN ASS'Y
CN00Z
I
H
MIRROR
MIRROR STOPPER
J

AV-48WP74
AV-56WP74
(No.52105)1-13
2.7.9 REAR PANEL
(1) Loosen 7 screws [ K ].
(2) Remove 4 screws [ L ].
(3) Raise slightly REAR PANEL upward.
(4) Take out the REAR PANEL.
NOTE :
• Before the rear panel is inserted into the cabinet, release
the short-circuit between the [SB] connector (1) pin and
(2) pin of the DIGITAL INPUT UNIT. (Refer to "CAUTION
AT DISASSEMBLY" on Page 11).
• After releasing the short-circuit between the [SB]
connectors, do not turn the power on until the rear panel
is inserted into the cabinet.
Fig.5
2.7.10 PARTITION
• Take out the REAR PANEL.
(1) Pull out the PARTITION back ward.
2.7.11 REAR COVER
• Take out the SPEAKER GRILLE.
• Take out the FRONT CONTROL BOX.
• Take out the SCREEN ASS'Y.
(1) Remove 2 screws [ M ]. (Fig.5)
(2) Remove 2 screws [ N ] from front side.
(3) Slightly pull for backside to disengage of the REAR
COVER from hooks.
(4) Take out the REAR COVER.
• Because of the large size, at least two persons are rec-
ommended for removal and reassemble.
Fig.6
Prior to starting the work, be sure to read the following
written instructions on the CAUTION LABEL attached to the
REAR PANEL.
UNPLUG THE POWER CORD FROM AC OUTLET BEFORE
OPEN THE REAR COVER (PANEL).
When the rear cover (panel) is removed, follow "CAUTION AT
DISASSEMBLY" procedure in the service manual before
plugging the TV's power cord into an AC outlet.
Failure to follow the procedure will result in PERMANENT
damage to some of the television features.
L
M
KREAR PANEL
PARTITION
BRACKET
REAR COVER
N

AV-48WP74
AV-56WP74
1-14 (No.52105)
2.7.12 MAIN UNIT
• Take out the SPEAKER GRILLE.
• Take out the connector [BH], [R], [BG] on the FRONT
CONTROL PWB.
• Take out the REAR PANEL.
(1) Remove 4 screws [ O ] from front side.
(2) Remove 1 screw [ P ] and 3 screws [ Q ] attaching the
MAIN CHASSIS and BODY.
(3) Pull out the MAIN UNIT rear side.
NOTE :
• Except for confirmation of projection of images on the
screen and audio output through the speakers, the
removed MAIN UNIT is still workable in the same state as
if it is still built in the TV set.Therefore,theMAIN UNIT can
be removed, if necessary, for board diagnosis, electric
testing, etc. apart from confirmation of screen images and
audio output.
• When wire clamps are removed during work, use care to
restore them precisely to their original positions.
Performance can be affected if these are not returned to
the original positions.
• Because of the large size, at least two persons are
recommended for removal and reassemble.
• When carrying the MAIN UNIT, use care not to drop,
shock or shake it.
• Do not stain or damage the lens of the PROJECTION
UNIT.
• Do not look through the PROJECTION UNIT.
2.7.12.1 CHECKING THE P.W. BOARD
When checking the MAIN PWB, POWER & DEF PWB, etc., raise
the MAIN UNIT with the HV DIVIDER side down for the sake of
convenience. You can checking the POWER & DEF PWB and
CONVERGENCE OUT PWB.
Fig.7
2.7.13 LINE FILTER PWB
• Take out the REAR PANEL.
• Take out the AV TERMINAL BOARD. (Refer to next page)
(1) Disconnect the connector [B], [F] on the LINE FILTER
PWB.
(2) Remove 3 screws [ R ] attaching the LINE FILTER
BRACKET and earth wire.
(3) Remove 3 screws [ S ] attaching LINE FILTER PWB.
(4) Take out the LINE FILTER PWB.
Fig.8
REAR SIDE
BODY
O
MAIN UNIT
Q
P
LINE FILTER BRACKET
LINE FILTER BRACKET
LINE FILTER PWB
R
S
BF
R

AV-48WP74
AV-56WP74
(No.52105)1-15
2.7.14 AV TERMINAL BOARD
• Take out the REAR PANEL
(1) Remove 9 screws [ T ].
(2) Remove 1 screws [ U ].
(3) Pull out the POWER CORD CLAMP from AV TERMINAL
BOARD left side.
(4) Remove the nut [ V ] attaching the ANTENNA TERMINAL.
(5) Take out the AV TERMINAL BOARD.
2.7.15 DIGITAL INPUT MODULE
• Take out the REAR PANEL
(1) Remove 2 screws [ W ] from rear side of the AV TERMINAL
BOARD.
(2) Take out the DIGITAL INPUT MODULE.
NOTE :
• When removing the DIGITAL INPUT MODULE, refer to
the "CAUTION AT DISASSEMBLY" section on page 11.
Fig.9
2.7.16 MAIN CHASSIS
• Take out the REAR PANEL.
• Take out the AV TERMINAL BOARD.
• Take out the LINE FILTER BRACKET.
(1) Remove 2 screws [ X ] both side of the MAIN CHASSIS.
(2) Remove 1 screws [ Y ] attaching the earth wire.
(3) Remove 1 screw [ P ] attaching the MAIN CHASSIS and
BODY.(Fig.7)
(4) Pull out the MAIN CHASSIS for back side.
NOTE :
• If necessary, remove the anode wires, connectors,
respectively.
Fig.10
AV TERMINAL
BOARD
W
VU
T
DIGITAL INPUT
MODULE
ANTENNA TERMINAL
POWER CORD
POWER CORD
CLAMP
X
X Y
EARTH WIRE
MAIN CHASSIS

AV-48WP74
AV-56WP74
1-16 (No.52105)
2.7.17 PROJECTION UNIT
• Take out the SPEAKER GRILLE
• Take out the FRONT CONTROL BOX
• Take out the REAR PANEL
• Take out the MAIN UNIT.
(1) Take out the CRT SOCKET PWB.
(2) Remove 4 screws [ Z ] attaching the PROJECTION UNIT.
(3) Pull out the PROJECTION UNIT, upward.
NOTE :
• Refer to "PROJECTION UNIT REPLACEMENT" on page
10 when taking out and replacing the PROJECTION
UNIT.
• When wire clamps are removed during work, use care to
restore them precisely to their original positions.
Performance can be affected if these are not returned to
the original positions.
2.7.18 HV DIVIDER
• Take out the REAR PANEL
(1) Remove 1 screws [ a ] attaching the HV DIVIDER.
(2) Take out the HV DIVIDER.
Wires of the transformer (FBT) and CRT of each
PROJECTION UNIT can be removed by turning the
connector portions.
NOTE :
• If necessary, remove the anode wires, and replacing the
HV DIVIDER, take care to correctly engage the [ b ]
connector.
2.7.19 REMOCON SENSOR PWB
• Take out the REAR PANEL
(1) Remove 1 screws [ c ] attaching the REMOCON SENSOR
PWB.
(2) Take out the REMOCON SENSOR PWB.
Fig.11
PROJECTION UNIT
REMOCON
SENSOR PWB
HV DIVIDER
Pull Turn
Z
a
b
c

AV-48WP74
AV-56WP74
(No.52105)1-17
2.8 REPLACEMENT OF CHIP COMPONENT
2.8.1 CAUTIONS
(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.
2.8.2 SOLDERING IRON
(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.
2.8.3 REPLACEMENT STEPS
1. How to remove Chip parts
[Resistors, capacitors, etc.]
(1) As shown in the figure, push the part with tweezers and
alternately melt the solder at each end.
(2) Shift with the tweezers and remove the chip part.
[Transistors, diodes, variable resistors, etc.]
(1) Apply extra solder to each lead.
(2) As shown in the figure, push the part with tweezers and
alternately melt the solder at each lead. Shift and remove
the chip part.
Note :
After removing the part, remove remaining solder from the
pattern.
2. How to install Chip parts
[Resistors, capacitors, 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. 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 Aas indicated in the figure.
(4) Then solder leads Band C.
SOLDER SOLDER
AB
C
A
B
C

AV-48WP74
AV-56WP74
1-18 (No.52105)
2.9 MEMORY IC REPLACEMENT
2.9.1 MEMORY IC
This memory IC stores data for proper operation of the video and
deflection circuits.
When replacing, be sure to use an IC containing this (initial
value) data.
Fig.1
2.9.2 MEMORY IC REPLACEMENT PROCEDURE
(1) Power off
Switch off the power and disconnect the power cord from
the wall outlet.
(2) Replace the memory IC
Initial value must be entered into the new IC.
(3) Power on
Connect the power cord to the wall outlet and switch on the
power.
(4) SERVICE MENU setting
a) Press [SLEEP TIMER] key and, while the indication of
SLEEP TIMER 0 MIN is being displayed, press
[DISPLAY] key and [VIDEO STATUS] key on the
remote control unit (Fig.2) simultaneously.
b) The SERVICE MENU screen of Fig.1 is displayed.
c) Verify what to set in the SERVICE MENU, and set
whatever is necessary (Fig.1).
Refer to the SERVICE ADJUSTMENT for setting.
d) Press the [BACK] key twice to return normal screen.
(5) Receive channel setting
Refer to the OPERATING INSTRUCTIONS (USER'S
GUIDE) and set the receive channels (Channels Preset) as
described.
(6) User settings
Check the user setting items according to after page.
Where these do not agree, refer to the OPERATING
INSTRUCTIONS (USER'S GUIDE) and set the items as
described. Fig.2
2.9.3 SERVICE ADJUSTMENT ITEM
SERVICE MENU
SERVICE MENU
1.PICTURE/SOUND
2.YC SEP
3.WHITE BALANCE
4.MEMORY SETUP
5.RF AFC
6.CONVER A
7.CONVER BD
8.PP
9.IP
0.GCR
RM-C1200G
POWER
VIDEO
STATUS
INPUT2
INPUT3
INPUT4
DIGITAL-IN
INPUT1
SPLIT
100+
3
9
6
RETURN+
/TV
MUTING
MENU
C.C.
BACK
TV
CATV VCR DVD
THEATER
PRO NATURAL
CINEMA
LIGHT
SLEEP TIMER DISPLAY SOUND
1
7
4
2
8
0
5
POP
FREEZE SWAP SELECT
INDEX
ASPECT
EZ SURF
+
CH
VOL VOL
+
CH
OK
REC
OPEN/CLOSE STILL/PAUSE
STOP PAUSE
PLAY FFREW
VCR CHANNEL
PREV NEXT
TV/VCR
VCR/DVD
POWER
SERVICE MENU SELECT KEY
MULTI SCREEN
POWER
NUMBER
FUNCTION
(UP)
FUNCTION
(RIGHT)
FUNCTION
(DOWN)
DISPLAY
FUNCTION
(LEFT)
MENU
SLEEP
TIMER
MEMORY
(MUTING)
VIDEO
STATUS
BACK
Setting item Item No. Remark Setting item Item No. Remark
1.PICTURE / SOUND 7.CONVER B
AUDIO A01~A27 Convergence adjustment ------
VIDEO S01~S99 8.PP
DEFLECTION D01~D32 Multi-picture adjustment and
setting ADM001~ADM034 Do not adjust
FACTORY setting F01~F70 PPA001~PPA008 Do not adjust
2.YC SEP PPB001~PPB036 Do not adjust
YC separation setting YCM001~YCM185 Do not adjust PPC001~PPC008 Do not adjust
YCS001~YCS114 Do not adjust PPD001~PPD025 Do not adjust
3.WHITE BALANCE 9.IP
LOW LIGHT / HIGH LIGHT
adjustment BR, DRV R, DRV B, CWT R, CWT G,
CWT B
DIST process setting IPA001~IPA120 Do not adjust
4.MEMORY SETUP ------ Do not adjust IPB001~IPB079 Do not adjust
5.RF AFC IPC001~IPC044 Do not adjust
Tuner AFC setting TUNER, AFC,FINE Do not adjust IPD001~IPD026 Do not adjust
6.CONER A IPE001~IPE015 Do not adjust
Convergence adjustment CPA01~CPA08 0.GCR
CCA01~CCA09 Ghost reduction setting Not use
CBA01~CBA80 Do not adjust