Funai LH7-M19BB Schematic

SERVICE MANUAL
This Service Manual is for the LH7-M19BB (A93N2EP) model. For the LH7-M19BB (A93N2EP) model, the letter (A93N2EP) is printed on the Serial Number Label on the back of the unit. Refer to the Serial Number Label on the right.
"A93N2EP"
19 COLOR LCD TELEVISION
LH7-M19BB
19 COLOR LCD TELEVISION
LH7-M19BB
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
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
Block Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
Schematic Diagrams / CBA and Test Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1
Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1
Exploded View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1
Mechanical Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1
Electrical Parts List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-1
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.

SPECIFICATIONS

< TUNER >
VHS/UHF Input ----------- 75 unbal., IEC Connector Center IF ------------------- SECAM-L 38.9MHz, SECAM-L’ 33.9MHz
Description Condition Unit Nominal Limit
1. Video S/N 80 dB --- 40
2. Audio S/N --- dB --- 40/40
< LCD PANEL >
Description Condition Unit Nominal Limit
1. Number of Pixels
2. Viewing Angle
<DVB-T>
Description Condition Unit Nominal Limit
1.
RECEIVED FREQ.RANGE (-60dBm, 45ch.) *1, *2
2. INPUT DYNAMIC RANGE (mix./max)
3. C/N PERFORMANCE
(-50dBm)
4. MULTIPATH (-50dBm)
a. Performance with
short delay echoes
b. Performance with
long delay echoes
Horizontal
Ver t i cal
Horizontal
Ver t i cal
+
-
c:*1 VHF HIGH 8ch.
UHF 45ch.
d:*2 VHF HIGH 8ch.
UHF 45ch.
c:*1 VHF HIGH 8ch.
UHF 45ch.
d:*2 VHF HIGH 8ch.
UHF 45ch.
UHF 45ch.
c:*3 d:*4 c:*3 d:*4
pixels pixels
kHz kHz
dBuV dBuV
dBuV dBuV
dB dB
dB dB
dB dB dB dB
1366
768
° °
---
---
1000
900
25/101 25/101
18/101 18/101
15 15
11 11
18.7
14.0
19.1
13.0
---
---
-85 to 85
-80 to 80
500 167
28/98 29/98
21/98 21/98
1818
1414
23202318
*1: modulation parameters = [8k 64QAM CR=2/3 GI=1/32] *2: modulation parameters = [8k 16QAM CR=3/4 GI=1/8] *3: modulation parameters = [2k 64QAM CR=2/3 GI=1/32] *4: modulation parameters = [2k 16QAM CR=3/4 GI=1/32]
< VIDEO >
Description Condition Unit Nominal Limit
1. Over Scan
2. Color Temperature
3. Resolution
4. Brightness AT 100% WHITE FIELD cd/m
Horizontal
Ver t i cal
AT 70% WHITE FIELD
x y
Horizontal
Ver t i cal
1-1 A93N2SP
line line
% %
°K 9200
2
5 5
0.286
0.295
400 350
260 ---
---
---
--­±0.008 ±0.008
---
---
< AUDIO >
All items are measured across 16 load at speaker output terminal.
Description Condition Unit Nominal Limit
1. Audio Output Power 10% THD: Lch/Rch W 3.0/3.0 2.0/2.0
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 Lch/Rch dB ---
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.
45/45
1-2 A93N2SP

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.
READING SHOULD NOT BE ABOVE 0.5 mA
LEAKAGE
DEVICE
BEING
TESTED
TEST ALL EXPOSED METAL SURFACES
ALSO TEST WITH PLUG REVERSED USING AC ADAPTER PLUG AS REQUIRED
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.
CURRENT
TESTER
+
EARTH GROUND
_
2-1 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.
2-2 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.
2-3 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
AC Line Voltage Clearance Distance (d), (d’)
220 to 240 V
Note: This table is unofficial and for reference only. Be sure to confirm the precise values.
3mm(d)
8mm(d’)
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.).
Chassis or Secondary Conductor
Primary Circuit
d' d
Exposed Accessible Part
Z
AC Voltmeter (High Impedance)
Fig. 1
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
AC Line Voltage Load Z Leakage Current (i)
2kRES.
Connected in
parallel
220 to 240 V
50k RES.
Connected in
parallel
Note: This table is unofficial and for reference only. Be sure to confirm the precise values.
i0.7mA AC Peak
i2mA DC
i0.7mA AC Peak
i2mA DC
One side of
B
Power Cord Plug Prongs
One side of power cord plug
prongs (B) to:
Antenna terminals
A/V Input, Output
Fig. 2
RF or
2-4 LTVP_ISP

STANDARD NOTES FOR SERVICING

Circuit Board Indications
1. The output pin of the 3 pin Regulator ICs is indicated as shown.
Top View
Out
2. For other ICs, pin 1 and every fifth pin are indicated as shown.
Pin 1
3. The 1st pin of every male connector is indicated as shown.
Pin 1
Input
In
Bottom View
5
10
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.
Pb free mark
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)
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.
Hot-air Flat Pack-IC Desoldering
CBA
Masking Tape
Tweezers
3-1 TVP_SN
Machine
Flat Pack-IC
Fig. S-1-2
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)
Flat Pack-IC
Desoldering Braid
Soldering Iron
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)
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.
Sharp Pin
Fine Tip Soldering Iron
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)
Fig. S-1-4
To Solid Mounting Point
CBA
Hot Air Blower
or
Iron Wire
Soldering Iron
Fig. S-1-5
Fine Tip Soldering Iron
Flat Pack-IC
Tweezers
Fig. S-1-6
3-2 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 pin 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.
Example :
Pin 1 of the Flat Pack-IC is indicated by a " " mark.
Fig. S-1-7
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 M) 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 M) 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.
<Incorrect>
CBA
Presolder
Flat Pack-IC
Fig. S-1-8
<Correct>
1M
CBA
Grounding Band
1M
CBA
Conductive Sheet or Copper Plate
3-3 TVP_SN

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.
[1] Stand
Assembly
[10] Junction CBA
[2] Rear Cabinet
[3] Tuner Shield
[4] Power Supply CBA
[8] LCD Module Assembly
[11] Function CBA
[12] Front Cabinet
[9] Speaker(s)
[5] Jack Holder
[6] Shield Box
[7] Digital Main CBA Unit
2. Disassembly Method
Removal
Step/
Loc.
Part
No.
Stand
[1]
Assembly
Rear
[2]
Cabinet
Tuner
[3]
Shield
Power
[4]
Supply CBA
[5] Jack Holder D2 2(S-7) ---
[6] Shield Box
Digital Main
[7]
CBA UnitD2D3
LCD
[8]
Module Assembly
[9] Speaker(s) D2
Junction
[10]
CBA
Remove/*Unhook/
Fig.
No.
Unlock/Release/
Unplug/Unclamp/
Note
Desolder
D1 3(S-1) ---
D1 12(S-2), 2(S-3), 3(S-4) ---
D2 (S-5) ---
9(S-6), *CN152, *CN301, *CN302, *CN303, *CN401,
D2
*CN404, *CN801,
D3
*CN802, *CN1001, *CN1002
D2D34(S-8), (S-9), 5(S-10),
2(H-1), *CN3901
--------------- ---
D2 (S-11) ---
4(S-12),Speaker Holder(s)
D2
Desolder ---
D3
---
---
---
Removal
Step/
Loc.
No.
Part
Fig.
Remove/*Unhook/
Unlock/Release/
No.
Unplug/Unclamp/
Note
Desolder
[11]
[12]
(1)
Function CBA
Front Cabinet
(2)
D2
2(S-13) ---
D3
D2 --------------- ---
(3)
(4)
(5)
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. N = Nut, L = Locking Tab, S = Screw, H = Hex 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 le . "
4-1 A93N2DC
(S-2)
[2] Rear Cabinet
(S-2)
(S-4)
(S-2)
(S-4)
(S-2)
[1] Stand Assembly
(S-2)
(S-3)
(S-1)
Fig. D1
4-2 A93N2DC
[12] Front Cabinet
[9] Speaker
Speaker Holder
[8] LCD Module Assembly
(S-12)
[10] Junction CBA
(S-13)
[11] Function CBA
[9] Speaker
Speaker Holder
(S-12)
(S-10)
(S-10)
[7] Digital Main CBA Unit
(S-6)
[6] Shield Box
[5] Jack Holder
[3] Tuner Shield
(S-8)
(H-1)
(S-9)
(S-7)
(S-8)
(S-5)
[4] Power Supply CBA
(S-11)
(S-6)
(S-6)
Fig. D2
4-3 A93N2DC
TV Cable Wiring Diagram
To LCD Module Assembly
Power Supply CBA
To LCD Module Assembly
CN1001
CN1002
CN801
To Speaker
AC CORD
CN301
CN302
CN303
CN404
CN401
CN152
CN802
To Speaker
CN3901
CN3701
CN3703
CN3702
CN3401
CN3704
Digital Main CBA Unit
Function CBA
CN101B
Junction CBA
CN101
CN101A
Fig. D3
4-4 A93N2DC

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.
service button
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.
Purity Check Mode
White mode
[7] button
[7] button
Black mode
A
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.
[7] button
Red mode
[7] button
Green mode
[7] button
Blue mode
[7] button
White 20% mode
Note:
When entering this mode, the default setting is White mode.
5-1 A93F0EA
2. VCOM Adjustment.
4. Auto Calibration [PC]
Test Point
Screen
M. EQ. Spec.
Color analyzer
Figure
To avoid interference from ambinent light, this adjustment should be performed in a dark room.
Perpendicularity
L = 3 cm
Color Analyzer
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. 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.
Adj. Point
[P / ]
buttons
See below
Purpose: To bring the color adjustment of PC into standard alignment.
Symptom of Misadjustment: If this adjustment is incorrect, PC signals do not reproduce the corresponding color.
1. Input SVGA 100% White signal.
2. Enter the service mode.
3. To enter the Auto Calibration adjustment mode, press [5] button on the service remote control unit.
4. To start auto adjustment, press [P ] button on the service remote control unit.
- In the auto adjustment mode, “Calibration Check”
appears on the screen.
- Upon completion, “OK” appears on the screen.
3. Auto Calibration [Component]
Purpose: To bring the color adjustment of each
component into standard alignment.
Symptom of Misadjustment: If this adjustment is incorrect, component signals do not reproduce the corresponding color.
1. Input 720P 100% Color Bar signal.
2. Enter the service mode.
3. To enter the Auto Calibration adjustment mode, press [6] button on the service remote control unit.
4. To start auto adjustment, press [P ] button on the service remote control unit.
- In the auto adjustment mode, “Calibration Check”
appears on the screen.
- Upon completion, “OK” appears on the screen.
5-2 A93F0EA
The following adjustment normally are not attempted in the field. Only when replacing the LCD Panel then adjust as a preparation.
5. White Balance Adjustment
[Video/Component/PC]
Purpose: To mix red, green and blue beams correctly
for pure white.
Symptom of Misadjustment: White becomes bluish or reddish.
Test Point
Screen
Adj. Point Mode Input
[P / ]
buttons
M. EQ. Spec.
[VIDEO]
C/D
White Raster
(APL 70%)
or
(APL 40%)
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 9200°K (x ±0.005).
8. Change the video signal input in step 2 and repeat from step 3.
=
0.286 / y= 0.295
Pattern Generator,
Color analyzer
Figure
To avoid interference from ambinent light, this adjustment should be performed in a dark room.
Perpendicularity
L = 3 cm
INPUT: WHITE 70%, 40%
1. Operate the unit for more than 20 minutes.
2. [VIDEO input] Input the White Raster (70%=70IRE, 40%=40IRE). [Component input] Input the 720P White Raster (70%=70IRE, 40%=40IRE). [PC input] Input the SVGA White Raster (70%=70IRE, 40%=40IRE).
x= 0.286 ± 0.005 y= 0.295 ± 0.005
Color Analyzer
INPUT SIGNAL
40%=40IRE
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.
70%=70IRE
5-3 A93F0EA

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.
6-1 A93F0INT
FLOW CHART NO.1
The power cannot be turned on.

TROUBLESHOOTING

Is the fuse (F601) normal?
Ye s
Is normal state restored when once unplugged power cord is plugged again several seconds?
Ye s
Is the AL+33V line voltage normal?
Ye s
Check each rectifying circuit of the secondary circuit and service it if defective.
FLOW CHART NO.2
The fuse blows out.
Check the presence that the primary component is leaking or shorted and service it if defective.
After servicing, replace the fuse (F601).
FLOW CHART NO.3
When the output voltage fluctuates.
No
No
No
See FLOW CHART No.2 <The fuse blows out.>
Check if there is any leak or short-circuiting on the primary circuit component, and service it if defective. (IC605, Q601, Q602, D602, D604, D605, D607, T601, R602)
Check the presence that the rectifying diode or circuit is shorted in each rectifying circuit of secondary side, and service it if defective.
Does the photocoupler circuit on the secondary side operate normally?
Ye s
Check IC605, D603, D606 and their periphery, and service it if defective.
FLOW CHART NO.4
When buzz sound can be heard in the vicinity of power circuit.
Check if there is any short-circuit on the rectifying diode and the circuit service it if defective. (D612, D619, D616, D622, D637, Q605, Q606, Q609, Q611, Q615, Q616)
No
Check IC605, Q603, D615, D620, D628 and their periphery, and service it if defective.
in each rectifying circuit of the secondary side, and
7-1 A93N2TR
FLOW CHART NO.5
AL+3.3V is not output.
Is approximately 7V voltage supplied to the collector of Q605?
Ye s
Is approximately 4V voltage supplied to the base of Q605?
Ye s
Replace Q605.
FLOW CHART NO.6
P-ON+5V is not output.
Is approximately 8V voltage supplied to the collector of Q616?
Ye s
Is approximately 6V voltage supplied to the base of Q616?
Ye s
Replace Q616.
No
No
No
No
Check D637, C628 and their periphery circuit, and service it if defective.
Check D634 and their periphery circuit, and service it if defective.
Check D637, C628 and their periphery circuit, and service it if defective.
Check Q610, D653, P-ON-H2 line and their periphery circuit, and service it if defective.
FLOW CHART NO.7
AL+33V is not outputted.
Is approximately 33V voltage supplied to the cathode of D619?
Ye s
Check if there is any leak or short-circuit on the loaded circuit, and service it if defective.
FLOW CHART NO.8
AL+15V is not outputted.
Is approximately 16V voltage supplied to the cathode of D612?
Ye s
Check if there is any leak or short-circuit on the loaded circuit, and service it if defective.
No
No
Check D619, D623, C616 and their periphery circuit, and service it if defective.
Check D612, D620, C613 and their periphery circuit, and service it if defective.
7-2 A93N2TR
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