FUNAI LT6-M22WB, A8C72EP, A8C73EP Service Manual
SERVICE MANUAL
This Service Manual is for the
LT6-M22BB(A8C72EP)
/LT6-M22WB(A8C73EP) model.
For the LT6-M22BB(A8C72EP)
/LT6-M22WB(A8C73EP) model,
the letter (A8C72EP)/(A8C73EP) is
printed on the Serial No. Label.
Refer to the Serial No. Label on the
right.
Serial No. Label
"A8C72EP"
Serial No. Label
"A8C73EP"
22″ COLOR LCD TELEVISION
LT6-M22BB/LT6-M22WB
22″ COLOR LCD TELEVISION
LT6-M22BB/LT6-M22WB
TABLE OF CONTENTS
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Important Safety Precautions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Standard Notes for Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Cabinet Disassembly Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Electrical Adjustment Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
How to Initialize the LCD Television. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Block Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
Schematic Diagrams / CBA and Test Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1
Exploded View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1
Mechanical Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1
Electrical Parts List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1
The LCD panel is manufactured to provide many years of useful life.
Occasionally a few non active pixels may appear as a tiny spec of color.
This is not to be considered a defect in the LCD screen.
1-1 A8C70SP
SPECIFICATIONS
< TUNER >
VHS/UHF Input ----------- 75Ω unbal., IEC Connector
Center IF ------------------- SECAM-L 38.9MHz, SECAM-L’ 33.9MHz
< LCD PANEL >
<DVB-T>
*1: modulation parameters = [8k 64QAM CR=2/3 GI=1/32]
*2: modulation parameters = [2k 64QAM CR=2/3 GI=1/32]
*3: modulation parameters = [2k 16QAM CR=3/4 GI=1/32]
< VIDEO >
Description Condition Unit Nominal Limit
1. Video S/N 80 dB --- 40
2. Audio S/N --- dB --- 40/40
Description Condition Unit Nominal Limit
1. Number of Pixels
Horizontal
Ver ti ca l
pixels
pixels
1680
1050
---
---
2. Viewing Angle
Horizontal
Ver ti ca l
°
°
-85 to 85
-80 to 80
---
---
Description Condition Unit Nominal Limit
1. RECEIVED
FREQ.RANGE
(-60dBm, 45ch.) *1
+
-
kHz
kHz
1000
900
500
-150
2. INPUT DYNAMIC
RANGE (mix./max) *1
VHF HIGH 7ch.
UHF 45ch.
dBm
dBm
-82.5/2
-81.1/2
-75/-10
-75/-10
3. C/N PERFORMANCE
*1
VHF HIGH 7ch.
UHF 45ch.
dB
dB
15
15
≦18
≦18
4. MULTIPATH
a. Performance with
short delay echoes
b. Performance with
long delay echoes
c. C/N Performance on
0dB echo channel
(14µs)
UHF 45ch.
c:*2
d:*3
c:*2
d:*3
c:*1
dB
dB
dB
dB
dB
18.7
14.0
19.1
13.0
20.7
≦23
≦20
≦23
≦18
≦24
Description Condition Unit Nominal Limit
1. Over Scan
Horizontal
Vertical
%
%
5
5
---
---
2. Color Temperature
AT 80% WHITE FIELD
x
y
°K 12000
0.272
0.278
--±0.005
±0.005
3. Resolution
Horizontal
Vertical
line
line
400
350
---
---
4. Brightness AT 100% WHITE FIELD cd/m
2
250 ---
1-2 A8C70SP
< AUDIO >
All items are measured across 8 Ω load at speaker output terminal.
Note: Nominal specifications represent the design specifications. All units should be able to approximate these.
Some will exceed and some may drop slightly below these specifications. Limit specifications represent
the absolute worst condition that still might be considered acceptable. In no case should a unit fail to meet
limit specifications.
Description Condition Unit Nominal Limit
1. Audio Output Power 10% THD: Lch/Rch W 1.0/1.0 0.8/0.8
2. Audio Distortion 500mW: Lch/Rch % 1.5/1.5 3.0/3.0
3. Audio Freq. Response
-
6dB: Lch
-
6dB: Rch
Hz
Hz
70 to 8 k
70 to 8 k
---
---
4. Audio S/N
VIDEO
Component
dB
dB
---
---
>45/45
>45/45
2-1 LTVP_ISP
IMPORTANT SAFETY PRECAUTIONS
Prior to shipment from the factory, our products are strictly inspected for recognized product safety and electrical
codes of the countries in which they are to be sold. However, in order to maintain such compliance, it is equally
important to implement the following precautions when a set is being serviced.
Safety Precautions for LCD TV
Circuit
1. Before returning an instrument to the
customer, always make a safety check of the
entire instrument, including, but not limited to, the
following items:
a. Be sure that no built-in protective devices are
defective and have been defeated during
servicing. (1) Protective shields are provided
on this chassis to protect both the technician
and the customer. Correctly replace all missing
protective shields, including any removed for
servicing convenience. (2) When reinstalling
the chassis and/or other assembly in the
cabinet, be sure to put back in place all
protective devices, including but not limited to,
nonmetallic control knobs, insulating
fishpapers, adjustment and compartment
covers/shields, and isolation resistor/capacitor
networks. Do not operate this instrument or
permit it to be operated without all
protective devices correctly installed and
functioning. Servicers who defeat safety
features or fail to perform safety checks
may be liable for any resulting damage.
b. Be sure that there are no cabinet openings
through which an adult or child might be able to
insert their fingers and contact a hazardous
voltage. Such openings include, but are not
limited to, (1) spacing between the LCD module
and the cabinet mask, (2) excessively wide
cabinet ventilation slots, and (3) an improperly
fitted and/or incorrectly secured cabinet back
cover.
c. Antenna Cold Check - With the instrument AC
plug removed from any AC source, connect an
electrical jumper across the two AC plug
prongs. Place the instrument AC switch in the
on position. Connect one lead of an ohmmeter
to the AC plug prongs tied together and touch
the other ohmmeter lead in turn to each tuner
antenna input exposed terminal screw and, if
applicable, to the coaxial connector. If the
measured resistance is less than 1.0 megohm
or greater than 5.2 megohm, an abnormality
exists that must be corrected before the
instrument is returned to the customer. Repeat
this test with the instrument AC switch in the off
position.
d. Leakage Current Hot Check - With the
instrument completely reassembled, plug the
AC line cord directly into a 230 V AC outlet. (Do
not use an isolation transformer during this
test.) Use a leakage current tester or a
metering system that complies with American
National Standards Institute (ANSI) C101.1
Leakage Current for Appliances and
Underwriters Laboratories (UL) 1410, (50.7).
With the instrument AC switch first in the on
position and then in the off position, measure
from a known earth ground (metal water pipe,
conduit, etc.) to all exposed metal parts of the
instrument (antennas, handle brackets, metal
cabinet, screw heads, metallic overlays, control
shafts, etc.), especially any exposed metal
parts that offer an electrical return path to the
chassis. Any current measured must not
exceed 0.5 milli-ampere. Reverse the
instrument power cord plug in the outlet and
repeat the test.
ANY MEASUREMENTS NOT WITHIN THE
LIMITS SPECIFIED HEREIN INDICATE A
POTENTIAL SHOCK HAZARD THAT MUST
BE ELIMINATED BEFORE RETURNING THE
INSTRUMENT TO THE CUSTOMER OR
BEFORE CONNECTING THE ANTENNA OR
ACCESSORIES.
2. Read and comply with all caution and safety-
related notes on or inside the receiver cabinet, on
the receiver chassis, or on the LCD module.
3. Design Alteration Warning - Do not alter or add
to the mechanical or electrical design of this LCD
TV receiver. Design alterations and additions,
including, but not limited to circuit modifications
and the addition of items such as auxiliary audio
and/or video output connections, might alter the
safety characteristics of this receiver and create a
hazard to the user. Any design alterations or
additions will void the manufacturer's warranty and
may make you, the servicer, responsible for
personal injury or property damage resulting
therefrom.
ALSO TEST WITH
PLUG REVERSED
USING AC
ADAPTER PLUG
AS REQUIRED
TEST ALL EXPOSED
METAL SURFACES
READING SHOULD
NOT BE ABOVE 0.5 mA
EARTH
GROUND
_
DEVICE
LEAKAGE
CURRENT
TESTER
+
BEING
TESTED
2-2 LTVP_ISP
4. Hot Chassis Warning -
a. Some TV receiver chassis are electrically
connected directly to one conductor of the AC
power cord and maybe safety-serviced without
an isolation transformer only if the AC power
plug is inserted so that the chassis is
connected to the ground side of the AC power
source. To confirm that the AC power plug is
inserted correctly, with an AC voltmeter,
measure between the chassis and a known
earth ground. If a voltage reading in excess of
1.0 V is obtained, remove and reinsert the AC
power plug in the opposite polarity and again
measure the voltage potential between the
chassis and a known earth ground.
b. Some TV receiver chassis normally have 85V
AC(RMS) between chassis and earth ground
regardless of the AC plug polarity. This chassis
can be safety-serviced only with an isolation
transformer inserted in the power line between
the receiver and the AC power source, for both
personnel and test equipment protection.
c. Some TV receiver chassis have a secondary
ground system in addition to the main chassis
ground. This secondary ground system is not
isolated from the AC power line. The two
ground systems are electrically separated by
insulation material that must not be defeated or
altered.
5. Observe original lead dress. Take extra care to
assure correct lead dress in the following areas: a.
near sharp edges, b. near thermally hot parts-be
sure that leads and components do not touch
thermally hot parts, c. the AC supply, d. high
voltage, and, e. antenna wiring. Always inspect in
all areas for pinched, out of place, or frayed wiring.
Check AC power cord for damage.
6. Components, parts, and/or wiring that appear to
have overheated or are otherwise damaged
should be replaced with components, parts, or
wiring that meet original specifications.
Additionally, determine the cause of overheating
and/or damage and, if necessary, take corrective
action to remove any potential safety hazard.
7. Product Safety Notice - Some electrical and
mechanical parts have special safety-related
characteristics which are often not evident from
visual inspection, nor can the protection they give
necessarily be obtained by replacing them with
components rated for higher voltage, wattage, etc..
Parts that have special safety characteristics are
identified by a ! on schematics and in parts lists.
Use of a substitute replacement that does not
have the same safety characteristics as the
recommended replacement part might create
shock, fire, and/or other hazards. The product's
safety is under review continuously and new
instructions are issued whenever appropriate.
Prior to shipment from the factory, our products
are strictly inspected to confirm they comply with
the recognized product safety and electrical codes
of the countries in which they are to be sold.
However, in order to maintain such compliance, it
is equally important to implement the following
precautions when a set is being serviced.
2-3 LTVP_ISP
Precautions during Servicing
A. Parts identified by the ! symbol are critical for
safety.
Replace only with part number specified.
B. In addition to safety, other parts and assemblies
are specified for conformance with regulations
applying to spurious radiation. These must also be
replaced only with specified replacements.
Examples: RF converters, RF cables, noise
blocking capacitors, and noise blocking filters, etc.
C. Use specified internal wiring. Note especially:
1) Wires covered with PVC tubing
2) Double insulated wires
3) High voltage leads
D. Use specified insulating materials for hazardous
live parts. Note especially:
1) Insulation Tape
2) PVC tubing
3) Spacers
4) Insulators for transistors.
E. When replacing AC primary side components
(transformers, power cord, etc.), wrap ends of
wires securely about the terminals before
soldering.
F. Observe that the wires do not contact heat
producing parts (heat sinks, oxide metal film
resistors, fusible resistors, etc.)
G. Check that replaced wires do not contact sharp
edged or pointed parts.
H. When a power cord has been replaced, check that
5~6 kg of force in any direction will not loosen it.
I. Also check areas surrounding repaired locations.
J. Use care that foreign objects (screws, solder
droplets, etc.) do not remain inside the set.
K. When connecting or disconnecting the internal
connectors, first, disconnect the AC plug from the
AC supply outlet.
L. When installing parts or assembling the cabinet
parts, be sure to use the proper screws and
tighten certainly.
2-4 LTVP_ISP
Safety Check after Servicing
Examine the area surrounding the repaired location
for damage or deterioration. Observe that screws,
parts and wires have been returned to original positions. Afterwards, perform the following tests and confirm the specified values in order to verify compliance
with safety standards.
1. Clearance Distance
When replacing primary circuit components, confirm
specified clearance distance (d) and (d') between soldered terminals, and between terminals and surrounding metallic parts. (See Fig. 1)
Table 1 : Ratings for selected area
Note: This table is unofficial and for reference only.
Be sure to confirm the precise values.
2. Leakage Current Test
Confirm the specified (or lower) leakage current between B (earth ground, power cord plug prongs) and
externally exposed accessible parts (RF terminals, antenna terminals, video and audio input and output terminals, microphone jacks, earphone jacks, etc.).
Measuring Method : (Power ON)
Insert load Z between B (earth ground, power cord
plug prongs) and exposed accessible parts. Use an
AC voltmeter to measure across both terminals of load
Z. See Fig. 2 and following table.
Table 2: Leakage current ratings for selected areas
Note: This table is unofficial and for reference only. Be sure to confirm the precise values.
AC Line Voltage Clearance Distance (d), (d’)
220 to 240 V
≥ 3mm(d)
≥ 6 mm(d’)
Fig. 1
Chassis or Secondary Conductor
Primary Circuit
d' d
Fig. 2
AC Voltmeter
(High Impedance)
Exposed Accessible Part
B
One side of
Power Cord Plug Prongs
Z
AC Line Voltage Load Z Leakage Current (i)
One side of power cord plug
prongs (B) to:
220 to 240 V
2kΩ RES.
Connected in
parallel
i≤0.7mA AC Peak
i≤2mA DC
RF or
Antenna terminals
50kΩ RES.
Connected in
parallel
i≤0.7mA AC Peak
i≤2mA DC
A/V Input, Output
3-1 TVP_SN
STANDARD NOTES FOR SERVICING
Circuit Board Indications
1. The output pin of the 3 pin Regulator ICs is
indicated as shown.
2. For other ICs, pin 1 and every fifth pin are
indicated as shown.
3. The 1st pin of every male connector is indicated as
shown.
Pb (Lead) Free Solder
Pb free mark will be found on PCBs which use Pb
free solder. (Refer to figure.) For PCBs with Pb free
mark, be sure to use Pb free solder. For PCBs
without Pb free mark, use standard solder.
How to Remove / Install Flat Pack-IC
1. Removal
With Hot-Air Flat Pack-IC Desoldering Machine:
1. Prepare the hot-air flat pack-IC desoldering
machine, then apply hot air to the Flat Pack-IC
(about 5 to 6 seconds). (Fig. S-1-1)
2. Remove the flat pack-IC with tweezers while
applying the hot air.
3. Bottom of the flat pack-IC is fixed with glue to the
CBA; when removing entire flat pack-IC, first apply
soldering iron to center of the flat pack-IC and heat
up. Then remove (glue will be melted). (Fig. S-1-6)
4. Release the flat pack-IC from the CBA using
tweezers. (Fig. S-1-6)
CAUTION:
1. The Flat Pack-IC shape may differ by models. Use
an appropriate hot-air flat pack-IC desoldering
machine, whose shape matches that of the Flat
Pack-IC.
2. Do not supply hot air to the chip parts around the
flat pack-IC for over 6 seconds because damage
to the chip parts may occur. Put masking tape
around the flat pack-IC to protect other parts from
damage. (Fig. S-1-2)
3. The flat pack-IC on the CBA is affixed with glue, so
be careful not to break or damage the foil of each
pin or the solder lands under the IC when
removing it.
Top View
Out
In
Bottom View
Input
5
10
Pin 1
Pin 1
Pb free mark
Fig. S-1-1
Hot-air
Flat Pack-IC
Desoldering
Machine
CBA
Flat Pack-IC
Tweezers
Masking
Tape
Fig. S-1-2
3-2 TVP_SN
With Soldering Iron:
1. Using desoldering braid, remove the solder from
all pins of the flat pack-IC. When you use solder
flux which is applied to all pins of the flat pack-IC,
you can remove it easily. (Fig. S-1-3)
2. Lift each lead of the flat pack-IC upward one by
one, using a sharp pin or wire to which solder will
not adhere (iron wire). When heating the pins, use
a fine tip soldering iron or a hot air desoldering
machine. (Fig. S-1-4)
3. Bottom of the flat pack-IC is fixed with glue to the
CBA; when removing entire flat pack-IC, first apply
soldering iron to center of the flat pack-IC and heat
up. Then remove (glue will be melted). (Fig. S-1-6)
4. Release the flat pack-IC from the CBA using
tweezers. (Fig. S-1-6)
With Iron Wire:
1. Using desoldering braid, remove the solder from
all pins of the flat pack-IC. When you use solder
flux which is applied to all pins of the flat pack-IC,
you can remove it easily. (Fig. S-1-3)
2. Affix the wire to a workbench or solid mounting
point, as shown in Fig. S-1-5.
3. While heating the pins using a fine tip soldering
iron or hot air blower, pull up the wire as the solder
melts so as to lift the IC leads from the CBA
contact pads as shown in Fig. S-1-5.
4. Bottom of the flat pack-IC is fixed with glue to the
CBA; when removing entire flat pack-IC, first apply
soldering iron to center of the flat pack-IC and heat
up. Then remove (glue will be melted). (Fig. S-1-6)
5. Release the flat pack-IC from the CBA using
tweezers. (Fig. S-1-6)
Note: When using a soldering iron, care must be
taken to ensure that the flat pack-IC is not
being held by glue. When the flat pack-IC is
removed from the CBA, handle it gently
because it may be damaged if force is applied.
Flat Pack-IC
Desoldering Braid
Soldering Iron
Fig. S-1-3
Fine Tip
Soldering Iron
Sharp
Pin
Fig. S-1-4
To Solid
Mounting Point
Soldering Iron
Iron Wire
or
Hot Air Blower
Fig. S-1-5
Fine Tip
Soldering Iron
CBA
Flat Pack-IC
Tweezers
Fig. S-1-6
3-3 TVP_SN
2. Installation
1. Using desoldering braid, remove the solder from
the foil of each pin of the flat pack-IC on the CBA
so you can install a replacement flat pack-IC more
easily.
2. The “●” mark on the flat pack-IC indicates pin 1.
(See Fig. S-1-7.) Be sure this mark matches the 1
on the PCB when positioning for installation. Then
presolder the four corners of the flat pack-IC. (See
Fig. S-1-8.)
3. Solder all pins of the flat pack-IC. Be sure that
none of the pins have solder bridges.
Instructions for Handling Semiconductors
Electrostatic breakdown of the semi-conductors may
occur due to a potential difference caused by
electrostatic charge during unpacking or repair work.
1. Ground for Human Body
Be sure to wear a grounding band (1 MΩ) that is
properly grounded to remove any static electricity that
may be charged on the body.
2. Ground for Workbench
Be sure to place a conductive sheet or copper plate
with proper grounding (1 MΩ) on the workbench or
other surface, where the semi-conductors are to be
placed. Because the static electricity charge on
clothing will not escape through the body grounding
band, be careful to avoid contacting semi-conductors
with your clothing.
Example :
Pin 1 of the Flat Pack-IC
is indicated by a " " mark.
Fig. S-1-7
Presolder
CBA
Flat Pack-IC
Fig. S-1-8
<Incorrect>
CBA
Grounding Band
Conductive Sheet or
Copper Plate
1MΩ
1MΩ
<Correct>
CBA
4-1 A8C72DC
CABINET DISASSEMBLY INSTRUCTIONS
1. Disassembly Flowchart
This flowchart indicates the disassembly steps for the
cabinet parts, and the CBA in order to gain access to
item(s) to be serviced. When reassembling, follow the
steps in reverse order. Bend, route and dress the
cables as they were.
2. Disassembly Method
Note:
(1) Order of steps in procedure. When reassembling,
follow the steps in reverse order. These numbers
are also used as the Identification (location) No. of
parts in figures.
(2) Parts to be removed or installed.
(3) Fig. No. showing procedure of part location
(4) Identification of parts to be removed, unhooked,
unlocked, released, unplugged, unclamped, or
desoldered.
P = Spring, L = Locking Tab, S = Screw,
CN = Connector
* = Unhook, Unlock, Release, Unplug, or Desolder
e.g. 2(S-2) = two Screws (S-2),
2(L-2) = two Locking Tabs (L-2)
(5) Refer to the following "Reference Notes in the
Ta b l e. "
Step/
Loc.
No.
Part
Removal
Fig.
No.
Remove/*Unhook/
Unlock/Release/
Unplug/Unclamp/
Desolder
Note
[1]
Stand
Cover
D1 2(S-1) ---
[2] Neck Cover D1 --------------- ---
[3]
Rear
Cabinet
D1 2(S-2), 3(S-3), 12(S-4) ---
[4]
Stand
Hinge
D1 --------------- ---
[5] Jack CBA
D2
D3
2(S-5), *CN107 ---
[7] Digital Main
CBA Unit
[5] Jack CBA
[13] IR Sensor CBA
[1] Stand Cover
[2] Neck Cover
[3] Rear Cabinet
[14] Function CBA
[16] Speaker(s)
[4] Stand Hinge
[6] Shield Box
[17] Front Cabinet
[10] Main CBA
[9] Shield(T)
[8] FFC Shield
[12] Inverter CBA
[11] Junction CBA
[15] LCD Module
Assembly
[6] Shield Box
D2
D3
2(S-6), (S-7), 3(S-8),
6(S-9), *CN101A,
*CN102A, *CN103A,
*CN104A, *CN4501,
*CN4502
---
[7]
Digital Main
CBA UnitD2D3
2(S-10), Connector IC
Card OSU
---
[8] FFC Shield D2 2(S-11) ---
[9] Shield(T) D2 2(S-12), (S-13) ---
[10] Main CBA
D2
D3
4(S-14), (S-15),
*CN106, *CN105A,
*CN802
---
[11]
Junction
CBA
D2
D3
*CN404A ---
[12]
Inverter
CBA
D2
D3
4(S-16), *CN401,
*CN402, *CN403,
*CN451
---
[13]
IR Sensor
CBA
D2
D3
(S-17), *CN301 ---
[14]
Function
CBA
D2
D3
--------------- ---
[15]
LCD
Module
Assembly
D2 --------------- ---
[16] Speaker(s) D2
4(S-18),
Speaker Holder(s)
---
[17]
Front
Cabinet
D2 --------------- ---
↓
(1)
↓
(2)
↓
(3)
↓
(4)
↓
(5)
Step/
Loc.
No.
Part
Removal
Fig.
No.
Remove/*Unhook/
Unlock/Release/
Unplug/Unclamp/
Desolder
Note
4-2 A8C72DC
[3] Rear Cabinet
(S-1)
(S-4)
(S-2)
(S-3)
(S-3)
(S-3)
(S-4)
(S-4)
(S-4)
(S-4)
(S-4)
[1] Stand Cover
[2] Neck Cover
[4] Stand Hinge
Fig. D1
4-3 A8C72DC
(S-16)
(S-16)
(S-18)
(S-18)
(S-17)
(S-15)
(S-14)
(S-14)
(S-11)
(S-12)
(S-5)
(S-8)
(S-7)
(S-8)
(S-6)
(S-9)
(S-9)
(S-10)
[5] Jack CBA
[13] IR Sensor
CBA
[6] Shield Box
[8] FFC
Shield
[9] Shield(T)
[11] Junction CBA
[12] Inverter CBA
[17] Front Cabinet
[10] Main CBA
[14] Function CBA
[16]
Speaker
[7] Digital Main
CBA Unit
[15] LCD Module
Assembly
[16] Speaker
Connector IC
Card OSU
Speaker
Holders
Speaker
Holders
(S-18)
(S-13)
Fig. D2
4-4 A8C72DC
TV Cable Wiring Diagram
IR Sensor CBA
Function
CBA
CN106
CN105A
CN301
Main CBA
CN802
CN202
CN4501 CN4502
CN11
Digital Main CBA Unit
Jack CBA
CN201
CN3704CN4503CN3701CN3601
CN103ACN102ACN101ACN104A
To LCD Module
Assembly
CN107
To Speaker
Fig. D3
CN403
CN402
CN451
CN401
To Speaker
Junction
CBA
Inverter CBA
To LCD Module
Assembly
CN404B
CN404A
CL404
5-1 A8C70EA
ELECTRICAL ADJUSTMENT INSTRUCTIONS
General Note: “CBA” is abbreviation for
“Circuit Board Assembly.”
Note: Electrical adjustments are required after
replacing circuit components and certain
mechanical parts. It is important to perform
these adjustments only after all repairs and
replacements have been completed.
Also, do not attempt these adjustments unless
the proper equipment is available.
Test Equipment Required
1. DC Voltmeter
2. Pattern Generato
3. Color Analyzer
How to make the Service remote
control unit:
Cut “A” portion of the attached remote control unit as
shown in Fig. 1.
How to set up the service mode:
Service mode:
1. Use the service remote control unit.
2. Turn the power on.
3. Press the service button on the service remote
control unit as shown in Fig.1.
Fig. 1
A
service button
5-2 A8C70EA
1. Purity Check Mode
This mode cycles through full-screen displays of red,
green, blue, and white to check for non-active pixels.
1. Enter the Service mode.
2. Each time pressing [7] button on the service
remote control unit, the display changes as
follows.
2. VCOM Adjustment.
1. Operate the unit for more than 20 minutes.
2. Set the color analyzer and bring the optical
receptor to the center on the LCD-Panel surface
after zero point calibration as shown above.
Note: The optical receptor must be set
perpendicularly to the LCD Panel surface.
3. Enter the Service mode.
4. [VCOM1]
Press [2] button on the service remote control unit.
[VCOM2]
Press [3] button on the service remote control unit.
5. Press [P / ] buttons on the service remote
control unit so that the color analyzer value
becomes minimum.
[7] button
Note:
When entering this mode, the default setting is White mode.
Purity Check Mode
[7] button
Red mode
Green mode
Blue mode
Black mode
[7] button
White mode
[7] button
[7] button
White 25% mode
[7] button
Test Point
Adj. Point
Screen
[P / ]
buttons
M. EQ. Spec.
Color analyzer
See below
Figure
Color Analyzer
It carries out in a darkroom.
L = 3 cm
Perpendicularity
5-3 A8C70EA
The following adjustment normally are not attempted in
the field. Only when replacing the LCD Panel then adjust
as a preparation.
3. White Balance Adjustment
Purpose: To mix red, green and blue beams correctly
for pure white.
Symptom of Misadjustment: White becomes bluish
or reddish.
1. Operate the unit for more than 20 minutes.
2. Input the White Raster(70%=70IRE, 30%=30IRE).
3. Set the color analyzer to the CHROMA mode and
bring the optical receptor to the center on the
LCD-Panel surface after zero point calibration as
shown above.
Note: The optical receptor must be set
perpendicularly to the LCD Panel surface.
4. Enter the Service mode. Press [ -] button on the
service remote control unit and select “C/D” mode.
5. [CUTOFF]
Press [3] button to select “COB” for Blue Cutoff
adjustment. Press [1] button to select “COR” for
Red Cutoff adjustment.
[DRIVE]
Press [6] button to select “DB” for Blue Drive
adjustment. Press [4] button to select “DR” for Red
Drive adjustment.
6. In each color mode, press [P / ] buttons to
adjust the values of color.
7. Adjust Cutoff and Drive so that the color
temperature becomes 12000°K (x
=
0.272 / y
=
0.278 ±0.005).
Tes t Point
Adj. Point Mode Input
Screen
[P / ]
buttons
[VIDEO]
C/D
White Raster
(APL 70%)
or
(APL 25%)
M. EQ. Spec.
Pattern Generator,
Color analyzer
x= 0.272 ± 0.005
y= 0.278 ± 0.005
Figure
Color Analyzer
It carries out in a darkroom.
L = 3 cm
Perpendicularity
INPUT: WHITE 70%, 30%
30%=30IRE
70%=70IRE
INPUT SIGNAL
6-1 A8CN0INT
HOW TO INITIALIZE THE LCD TELEVISION
How to initialize the LCD television:
1. Turn the power on.
2. To enter the service mode, press the service
button on the service remote control unit. (Refer to
page 5-1.)
- To cancel the service mode, Press [ ] button on
the remote control unit.
3. Press [ ] button on the service remote control
unit to initialize the LCD television.
4. "INITIALIZED" will appear in the upper right of the
screen. "INITIALIZED" color will change to green
from red when initializing is complete.
7-1
System Control Block Diagram
A8C72BLS
BLOCK DIAGRAMS
LED1
KEY SWITCH
IC4700
(SUB MICRO CONTROLLER)
IC4513
(MAIN MICRO CONTROLLER)
3
XOUT
XIN
X3101
4MHz
OSC
DIGITAL MAIN CBA UNIT
IR SENSOR CBAFUNCTION CBAMAIN CBA
CN301
REMOTE
SENSOR
RS301
+3.3V
D302
POWER
STANDBY
D303
LED144
CN202
REMOTE22
P-ON-H155
CN104ACN3601
REMOTE22 4
101211
PROTECT3
BACKLIGHT-ADJ
BACKLIGHT-SW
CN105A
REMOTE
11
12
RXD
15
6
8
CLKOUT
CLKIN
X3301
25MHz
OSC
U25
U26
P-ON-H1
TO
INVERTER
BLOCK
DIAGRAM
(CL404)
BACKLIGHT-ADJ
AC24
BACKLIGHT-SW
A2
TXD1
P22
TO DIGITAL
SIGNAL
PROCESS
BLOCK
DIAGRAM
TO POWER
SUPPLY
BLOCK
DIAGRAM
PROTECT1
22
P-ON-H1
14
P-ON-H2
13
P-ON-H2
P-ON-H1125
TXD
16
RXD1
N22
AMP-MUTE-SUB
18
REMOTE
R22
RESET-MAIN
5
RESET-MAIN
TO AUDIO-2
BLOCK
DIAGRAM
V24
LED144
REMOTE22
P-ON-H155
CN201
KEY-IN166
CN106
LED118 8
CN101A
P-ON-H213 13
CN3701
KEY-IN125 1
KEY-IN1
24
VCOM-PWM
21
VCOM-PWM
AA2
AMP-MUTE-MAIN
AMP-MUTE
SCL
SDA
19
20
IC3102 (MEMORY)
5
6
SDA
SCL
PROTECT2
RESET
23
PROTECT121 5
CN101ACN3701
PROTECT220 6
RESET17 9
4
PROTECT3
PROTECT319 7
IC3706 (MEMORY)
SPI-CLK
SPI-DO
SPI-DI
SPI-CS
SCK
SI
SO
CS
Y25
Y24
W25
W24
652
1
AF12
AE12
SCL
SDA
TO AUDIO-1
BLOCK
DIAGRAM
SCL
SDA
NICAM-RESET
B11
NICAM-RESET
SCART-MUTE
B2
SCART-MUTE
SCL
SDA
TO VIDEO
BLOCK
DIAGRAM
TO VIDEO
BLOCK
DIAGRAM
24223
3
BACKLIGHT-ADJ
BACKLIGHT-SW
CN104ACN3601
PROTECT1
PROTECT2
RESET
TO POWER
SUPPLY
BLOCK
DIAGRAM
INPUT0
A11
INPUT0
INPUT1
E12
INPUT1
INPUT2
D12
INPUT2
D1
SLOW-SW1E1FBIN1
C12
S-SW
SLOW-SW1
FBIN1
S-SW
INPUT2
Q3823
Q3819
Q3822
MAIN CBA
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