LG 42LG61 (CHASSIS:LA84B) Service Manual ▷ View online
- 5 -
IC Remove/Replacement
Some chassis circuit boards have slotted holes (oblong) through
which the IC leads are inserted and then bent flat against the
circuit foil. When holes are the slotted type, the following technique
should be used to remove and replace the IC. When working with
boards using the familiar round hole, use the standard technique
as outlined in paragraphs 5 and 6 above.
Some chassis circuit boards have slotted holes (oblong) through
which the IC leads are inserted and then bent flat against the
circuit foil. When holes are the slotted type, the following technique
should be used to remove and replace the IC. When working with
boards using the familiar round hole, use the standard technique
as outlined in paragraphs 5 and 6 above.
Removal
1. Desolder and straighten each IC lead in one operation by gently
1. Desolder and straighten each IC lead in one operation by gently
prying up on the lead with the soldering iron tip as the solder
melts.
melts.
2. Draw away the melted solder with an anti-static suction-type
solder removal device (or with solder braid) before removing the
IC.
IC.
Replacement
1. Carefully insert the replacement IC in the circuit board.
2. Carefully bend each IC lead against the circuit foil pad and
1. Carefully insert the replacement IC in the circuit board.
2. Carefully bend each IC lead against the circuit foil pad and
solder it.
3. Clean the soldered areas with a small wire-bristle brush.
(It is not necessary to reapply acrylic coating to the areas).
"Small-Signal" Discrete Transistor
Removal/Replacement
1. Remove the defective transistor by clipping its leads as close as
Removal/Replacement
1. Remove the defective transistor by clipping its leads as close as
possible to the component body.
2. Bend into a "U" shape the end of each of three leads remaining
on the circuit board.
3. Bend into a "U" shape the replacement transistor leads.
4. Connect the replacement transistor leads to the corresponding
4. Connect the replacement transistor leads to the corresponding
leads extending from the circuit board and crimp the "U" with
long nose pliers to insure metal to metal contact then solder
each connection.
long nose pliers to insure metal to metal contact then solder
each connection.
Power Output, Transistor Device
Removal/Replacement
1. Heat and remove all solder from around the transistor leads.
2. Remove the heat sink mounting screw (if so equipped).
3. Carefully remove the transistor from the heat sink of the circuit
Removal/Replacement
1. Heat and remove all solder from around the transistor leads.
2. Remove the heat sink mounting screw (if so equipped).
3. Carefully remove the transistor from the heat sink of the circuit
board.
4. Insert new transistor in the circuit board.
5. Solder each transistor lead, and clip off excess lead.
6. Replace heat sink.
5. Solder each transistor lead, and clip off excess lead.
6. Replace heat sink.
Diode Removal/Replacement
1. Remove defective diode by clipping its leads as close as
1. Remove defective diode by clipping its leads as close as
possible to diode body.
2. Bend the two remaining leads perpendicular y to the circuit
board.
3. Observing diode polarity, wrap each lead of the new diode
around the corresponding lead on the circuit board.
4. Securely crimp each connection and solder it.
5.
5.
Inspect (on the circuit board copper side) the solder joints of
the two "original" leads. If they are not shiny, reheat them and if
necessary, apply additional solder.
necessary, apply additional solder.
Fuse and Conventional Resistor
Removal/Replacement
1. Clip each fuse or resistor lead at top of the circuit board hollow
Removal/Replacement
1. Clip each fuse or resistor lead at top of the circuit board hollow
stake.
2. Securely crimp the leads of replacement component around
notch at stake top.
3. Solder the connections.
CAUTION: Maintain original spacing between the replaced
component and adjacent components and the circuit board to
prevent excessive component temperatures.
component and adjacent components and the circuit board to
prevent excessive component temperatures.
Circuit Board Foil Repair
Excessive heat applied to the copper foil of any printed circuit
board will weaken the adhesive that bonds the foil to the circuit
board causing the foil to separate from or "lift-off" the board. The
following guidelines and procedures should be followed whenever
this condition is encountered.
Excessive heat applied to the copper foil of any printed circuit
board will weaken the adhesive that bonds the foil to the circuit
board causing the foil to separate from or "lift-off" the board. The
following guidelines and procedures should be followed whenever
this condition is encountered.
At IC Connections
To repair a defective copper pattern at IC connections use the
following procedure to install a jumper wire on the copper pattern
side of the circuit board. (Use this technique only on IC
connections).
To repair a defective copper pattern at IC connections use the
following procedure to install a jumper wire on the copper pattern
side of the circuit board. (Use this technique only on IC
connections).
1. Carefully remove the damaged copper pattern with a sharp
knife. (Remove only as much copper as absolutely necessary).
2. carefully scratch away the solder resist and acrylic coating (if
used) from the end of the remaining copper pattern.
3. Bend a small "U" in one end of a small gauge jumper wire and
carefully crimp it around the IC pin. Solder the IC connection.
4. Route the jumper wire along the path of the out-away copper
pattern and let it overlap the previously scraped end of the good
copper pattern. Solder the overlapped area and clip off any
excess jumper wire.
copper pattern. Solder the overlapped area and clip off any
excess jumper wire.
At Other Connections
Use the following technique to repair the defective copper pattern
at connections other than IC Pins. This technique involves the
installation of a jumper wire on the component side of the circuit
board.
Use the following technique to repair the defective copper pattern
at connections other than IC Pins. This technique involves the
installation of a jumper wire on the component side of the circuit
board.
1. Remove the defective copper pattern with a sharp knife.
Remove at least 1/4 inch of copper, to ensure that a hazardous
condition will not exist if the jumper wire opens.
condition will not exist if the jumper wire opens.
2. Trace along the copper pattern from both sides of the pattern
break and locate the nearest component that is directly
connected to the affected copper pattern.
connected to the affected copper pattern.
3. Connect insulated 20-gauge jumper wire from the lead of the
nearest component on one side of the pattern break to the lead
of the nearest component on the other side.
Carefully crimp and solder the connections.
CAUTION: Be sure the insulated jumper wire is dressed so the
it does not touch components or sharp edges.
of the nearest component on the other side.
Carefully crimp and solder the connections.
CAUTION: Be sure the insulated jumper wire is dressed so the
it does not touch components or sharp edges.
- 6 -
SPECIFICATION
NOTE : Specifications and others are subject to change without notice for improvement.
4. General Specification(TV)
No. Item
Specification Remark
1.
Receiving System
ATSC/ NTSC-M
2.
Available Channel
1) VHF : 02~13
2) UHF : 14~69
3) DTV : 02-69
4) CATV : 01~135
5) CADTV : 01~135
3.
Input Voltage
100 - 240V~, 50/60Hz
4. Market
NORTH
AMERICA
5.
Screen Size
42 inch Wide(1920 x 1080)_FHD+120Hz
6. Aspect
Ratio
16:9
7. Tuning
System
FS
8. LCD
Module
LC420WUF-SAB
LPL Without Inv(FHD+120Hz)
9.
Operating Environment
1) Temp : 0 ~ 40 deg
2) Humidity : ~ 80 %
10.
Storage Environment
1) Temp : -20 ~ 60 deg
2) Humidity : ~ 85 %
1. Application Range.
This spec sheet is applied to the 37"/42"/47"/52" LCD TV used
LA84B chassis.
LA84B chassis.
2. Specification
Each part is tested as below without special appointment
2.1 Temperature : 25±5°C(77±9°F), CST : 40±5°C
2.2 Relative Humidity : 65±10%
2.3 Power Voltage : Standard input voltage
2.2 Relative Humidity : 65±10%
2.3 Power Voltage : Standard input voltage
(100~240V@ 50/60Hz)
• Standard Voltage of each products is marked by models
• Standard Voltage of each products is marked by models
2.4 Specification and performance of each parts are followed
each drawing and specification by part number in
accordance with BOM .
accordance with BOM .
2.5 The receiver must be operated for about 20 minutes prior
to the adjustment.
3. Test method
3.1 Performance : LGE TV test method followed.
3.2 Demanded other specification
3.2 Demanded other specification
Safety : UL, CSA, IEC specification
3.3 EMC : FCC, ICES, IEC specification
- 7 -
5. Chrominance & Luminance Specification
No
Item
Min
Typ
Max
Unit
Measurement Result
Remark
1.
White peak brightness
400
500
cd/m
2
453
Pass
37/ 42/ 47LG60-UA, 42LG61-UA
(Center 1- point / Full White Pattern)
360
450
52LG60-UA
2.
White average brightness
cd/m
2
N/A N/A
N/A
3.
Brightness uniformity
80
%
88. 7
Pass Full white
4.
Color coordinate
RED
X
Typ.
0.640
Typ.
0.641
Pass 42LG60-UA, 42LG61-UA
-0.03
0.638
+0.03
37LG60-UA
0.638
47LG60-UA
0.610
0.640
0.670
52LG60-UA
Y
Typ.
0.335
Typ.
0.334 Pass
42LG60-UA,
42LG61-UA
-0.03
0.334
+0.03
37LG60-UA
0.335
47LG60-UA
0.300
0.330
0.360
52LG60-UA
GREEN
X
Typ.
0.289
Typ.
0.287
Pass 42LG60-UA, 42LG61-UA
-0.03
0.291
+0.03
37LG60-UA
0.289
47LG60-UA
0.250
0.280
0.310
52LG60-UA
Y
Typ.
0.610
Typ.
0.608 Pass
42LG60-UA,
42LG61-UA
-0. 03
0.607
+0.03
37LG60-UA
0.609
47LG60-UA
0.570
0.600
0.630
52LG60-UA
BLUE
X
Typ.
0.144 Typ.
0.143 Pass. 42LG60-UA, 42LG61-UA
-0.03
0.145
+0.03
37LG60-UA
0.145 47LG60-UA
0.120
0.150
0.180
52LG60-UA
Y
Typ. 0.066
Typ.
0.064 Pass
42LG60-UA,
42LG61-UA
-0.03
0.062
-0.03
37LG60-UA
0.063
47LG60-UA
0.030
0.060
0.090
52LG60-UA
WHITE
X
0.279 0.276
Pass
37/42/47LG60-UA,
42LG61-UA
0.242
0.272
0.302
52LG60-UA
Y
0.292
0.291 Pass
37/42/47LG60-UA,
42LG61-UA
0.247
0.277
0.307
52LG60-UA
5.
Color coordinate uniformity
N/A
N/A
6.
Contrast ratio
1000:1 1400:1
37/42LG60-UA, 42LG61-UA
900:1 1300:1
47LG60-UA
1200:1 1800:1
52LG60-UA
7.
Dynamic Contrast Ratio
8000:1 10000:1
37/42/47/52LG60-UA,42LG61-UA
8.
Color Temperature
Cool
10000 11000 12000
10500 Pass
<Test Condition>
Standard 8300
9300
10300
9500
HDMI
Input
Warm
5500
6500
7500
7300
85% Full white pattern
9.
Color Distortion,DG
10.0
%
7
Pass
10.
Color Distortion,DP
10.0
deg
8
Pass
11.
Color S/N, AM/FM
43.0
dB
45
Pass
12.
Color Killer Sensitivity
-80
dBm
-83
Pass
- 8 -
Peak & average Brightness & Contrast measure standard specification
- White Peak brightness measure specification
- White Peak brightness measure specification
1) In non-impressed condition, measure peak brightness displayable as much as possible LCD module.
2) Measuring instrument: CA-110 or a sort of Color Analyzer.
3) Pattern Generator : VG-828 or a sort of digital pattern generator (displayable Full White & 1/25 White Window pattern)
4) Measure condition
2) Measuring instrument: CA-110 or a sort of Color Analyzer.
3) Pattern Generator : VG-828 or a sort of digital pattern generator (displayable Full White & 1/25 White Window pattern)
4) Measure condition
- Test pattern: in center, 1/5(H)x1/5(V) of Window Pattern (white pattern in non-impressed condition)
- SET condition : Contrast & Brightness Level 100%
- Environment condition : Dark room in the non outside light
- Video menu option condition
- SET condition : Contrast & Brightness Level 100%
- Environment condition : Dark room in the non outside light
- Video menu option condition
5) Measurement
- Do heat-run LCD module at 30minutes in normal temperature (25°…) by using full white pattern of 15% signal level(38 gray
level).
- Impress test pattern signal in 1/5(H) * 1/5(V) White Window of 100%(255Gray Level)
- measure 3 times brightness of central white window, and mark peak brightness in max brightness degree
- measure the same condition in video signal /RGB signal.
- measure 3 times brightness of central white window, and mark peak brightness in max brightness degree
- measure the same condition in video signal /RGB signal.
Average Brightness measure specification
1) Impress 100%(255Gray Level) full white pattern at the same peak brightness measurement.
2) Measure average brightness in 9 points.
2) Measure average brightness in 9 points.
Contrast ratio measure specification
1) Test display signal : 30x30 dots White Window signal & all Black Raster signal
2) Dark room measure condition : Using touch type Color analyzer CA-100 Dark room in the non outside light
3) Bright room measure condition : In bright room of 150Lx illumination in the panel surface, locate a source of light on the above
2) Dark room measure condition : Using touch type Color analyzer CA-100 Dark room in the non outside light
3) Bright room measure condition : In bright room of 150Lx illumination in the panel surface, locate a source of light on the above
45°of the panel surface.
4) Measure method
- In standard test condition, impress 30x30 dots White Window Pattern signal .
Measure center peak brightness degree Lw of white window
- Impress black Raster signal as contrast ratio measurement signal.
Measure black brightness degree Lb of PDP central
Calculate the following numerical formula.
Contrast ratio = Lw / Lb
Calculate the following numerical formula.
Contrast ratio = Lw / Lb
* If it does not use Prior measurement, use generally simple test measurement.
The Correct measure specification is followed by IEC61988-2/CD, JAPAN EIAJ-2710
Signal
Picture Mode
Fresh Contrast
Fresh Color
Black Level
RF NTSC-M Vivid
Off
Off
Low
AV NTSC-J Vivid Off
Off High
Component 720P
Vivid
Off
Off
High
RGB 1024x768 Vivid
Off
NA
NA
HDMI DTV
720P Vivid
Off
Off
Low
1 4 7
2 5 8
3 6 9
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