DOWNLOAD LG 42LB9RTA (CHASSIS:LP7BB) Service Manual ↓ Size: 5.26 MB | Pages: 31 in PDF or view online for FREE

Model
42LB9RTA (CHASSIS:LP7BB)
Pages
31
Size
5.26 MB
Type
PDF
Document
Service Manual
Brand
Device
TV / LCD
File
42lb9rta-chassis-lp7bb.pdf
Date

LG 42LB9RTA (CHASSIS:LP7BB) 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.
Removal
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.
2.  Draw  away  the  melted  solder  with  an  anti-static  suction-type
solder removal device (or with solder braid) before removing the
IC.
Replacement
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
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
leads  extending  from  the  circuit  board  and  crimp  the  "U"  with
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
board.
4.  Insert new transistor in the circuit board.
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
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.
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.
Fuse and Conventional Resistor
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.
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.
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).
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.
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.
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.
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.
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.
- 6 -
1. Application range
This  spec  sheet  is  applied  to  the  LCD  TV  used  LP7BB
chassis
2. Specification
Each part is tested as below without special appointment.
(1) Temperature : 25 ± 5°C(77 ± 9°F), CST : 40 ± 5°C
(2) Relative Humidity : 65% ± 10%
(3) Power Voltage : Standard  input  voltage  (100-240V~,
50/60Hz)
*Standard Voltage of each products is marked by models
(4) Specification  and  performance  of  each  parts  are  followed
each  drawing  and  specification  by  part  number  in
accordance with BOM.
(5) The receiver must be operated for about 20 minutes prior
to the adjustment.
3. Test method
(1) Performance : LGE TV test method followed
(2) Demanded other specification
Safety
: CE, IEC Specification
EMC
: CE, IEC
SPECIFICATION
NOTE : Specifications and others are subject to change without notice for improvement.
4. General TV Specification
No
Item
Specification
Remark
1. 
Video input applicable system
NTSC-M, PAL M/N
2. 
Receivable Broadcasting System
1) NTSC
2) PAL M
3) PAL N
3. 
RF Input Channel
BAND
NTSC
VHF
2 ~ 13
UHF
14 ~ 69
CATV 
1 ~ 125
4. 
Input Voltage
100-240V~ / 50Hz, 60Hz 
5.
Market
Central & South America
6.
Operating Environment
1) Temp  : 0 ~ 40 deg
2) Humidity : 10 ~ 90 %RH
7. 
Storage Environment
1) Temp  : -20 ~ 50 deg
2) Humidity : 10 ~ 90 %RH
8.
Power Consumption
Power on
≤ 260(42”)
(Green)
≤ 220(32”)
9.
Stand by
Cool
≤ 1W(32”, 42”)
Warm
≤ 40W(32”, 42”)
When recordign the manual recording
10.
Frequency range
H : 31 ~ 61 khz
PC Input
V : 56 ~ 75 Hz
11.
Video Input (2EA)
NTSC, PAL M/N
12.
S-Video Input (1EA)
NTSC, PAL M/N
Side only
13.
Component Input (2EA)
Y/Cb/Cr, Y/Pb/Pr
14.
RGB Input (1EA)
RGB-PC
15.
HDMI Input (2EA)
HDMI-PC
HDMI-DTV
16.
Audio Input (5EA)
PC Audio, Component (2EA), AV(2EA)
L/R Input
17.
Audio variable out (1EA)
18.
USB Input (1EA)
DivX, MP3, JPEG
19.
AV out (1EA)
- 7 -
5. General Module Specification
No
Item
Specification
Remark
1 .
Panel
42" TFT WXGA LCD
32" TFT WXGA LCD
2.
LCD Module
Outline 
42"
983 x 576 x 47.3
(H)mm x (V)mm x (D)mm
Dimension
32"
760.0 x 450.0 x 48.0
Pixel Pitch
42"
0.227 x 0.681 x RGB
mm
32"
0.17025 x 0.51075 x RGB
Pixel Format
1366 x 768 Pixels RGB strip arrangement
Coating
Hard coating(3H), Anti-glare treatment 
of the front polarizer, 
Back Light
42"
18CCFL
32"
18CCFL
6. Set Optical Feature (LCD Module)
No
Item
Min
Typ
Max
Unit
Maker
Remark
1.
Luminance
400
500
LPL(0RT)
- 50cm from the surface
32",42"
- Full White Pattern
2.
View angle (R/L, U/D)
178/178
degree
LPL 32”, 42”
- CR > 10
3.
White 
White
X
-0.03
0.279/0.279/0.279
+0.03
coordinate
Y
0.292/0.292/0.292
Red
X
0.635/0.636/0.635
Y
0.339/0.343/0.344
Green
X
0.282/0.284/0.286
Y
0.606/0.615/0.614
Blue
X
0.145/0.144/0.146
Y
0.064/0.063/0.061
4.
Contrast ratio
CR
600
800
32"
LPL(0-RT)
800
1000
42"
LPL(0-RT)
5.
Luminance Variation
1.3
- 8 -
7. Component Video Input (Y, PB, PR)
No
Resolution
H-freq(kHz)
V-freq.(kHz)
Pixel clock(MHz)
Remarks
1.
720*480
15.73
59.94
13.500
SDTV, DVD 480I(525I)
720*480
15.75
60.00
13.514
SDTV, DVD 480I(525I)
2.
720*576
15.625
50.00
13.500
SDTV, DVD 576I(625I)
3.
720*480
31.47
59.94
27.000
SDTV 480P
720*480
31.50
60.00
27.027
SDTV 480P
4.
720*576
31.25
50.00
27.000
SDTV 576P
5.
1280*720
44.96
59.94
74.176
HDTV 720P
1280*720
45.00
60.00
74.250
HDTV 720P
6.
1280*720
37.50
50.00
74.25
HDTV 720P 50Hz
7.
1920*1080
33.72
59.94
74.176
HDTV 1080I
1920*1080
33.75
60.00
74.250
HDTV 1080I
8.
1920*1080
28.125
50.00
74.250
HDTV 1080I 50Hz, 
9.
1920*1080
67.5
60.00
148.5
HDTV 1080P
10.
1920*1080
56.25
50
148.5
HDTV 1080P 50Hz
8.  RGB Input ( PC )
No
Resolution
H-freq(kHz)
V-freq.(kHz)
Pixel clock(MHz)
Remarks
1
720*400
31.469
70.08
28.32
DOS
2.
640*480
31.469
59.94
25.17
VESA(VGA)
3
640*480
37.500
75.00
31.50
VESA(VGA)
4
800*600
37.879
60.31
40.00
VESA(SVGA)
5
800*600
46.875
75.00
49.50
VESA(SVGA)
6
1024*768
48.363
60.00
65.00
VESA(XGA)
7
1024*768
56.476
70.06
78.75
VESA(XGA)
8
1024*768
60.023
75.02
79.50
VESA(XGA)
9
1280*768
47.776
59.87
80.125
WXGA(42XGA,50",60")
10
1360*768
47.712
60.01
85.50
WXGA(42XGA,50",60")
11
1366*768
47.700
60.00
84.62
WXGA(42XGA,50",60")
9. HDMI Input ( PC )
No
Resolution
H-freq(kHz)
V-freq.(kHz)
Pixel clock(MHz)
Remarks
1
720*400
31.469
70.08
28.32
DOS
2
640*480
31.469
59.94
25.17
VESA(VGA)
3
640*480
37.500
75.00
31.50
VESA(VGA)
4
800*600
37.879
60.31
40.00
VESA(SVGA)
5
800*600
46.875
75.00
49.50
VESA(SVGA)
6
1024*768
48.363
60.00
65.00
VESA(XGA)
7
1024*768
56.476
70.06
75.00
VESA(XGA)
8
1024*768
60.023
75.02
78.75
VESA(XGA)
9
1280*768
47.776
59.87
79.50
WXGA(42XGA,50",60")
10
1360*768
47.712
60.01
85.50
WXGA(42XGA,50",60")
11
1366*768
47.700
60.00
84.62
WXGA(42XGA,50",60")
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