DOWNLOAD LG 32LN49XX / 32LN4900 (CHASSIS:LB35B) Service Manual ↓ Size: 6 MB | Pages: 58 in PDF or view online for FREE

Model
32LN49XX 32LN4900 (CHASSIS:LB35B)
Pages
58
Size
6 MB
Type
PDF
Document
Service Manual
Brand
Device
TV / LCD
File
32ln49xx-32ln4900-chassis-lb35b.pdf
Date

LG 32LN49XX / 32LN4900 (CHASSIS:LB35B) 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 cir-
cuit 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 remain-
ing 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 pos-
sible 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 when-
ever 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 connec-
tions).
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 con-
nected 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 -
SPECIFICATION
NOTE : Specifications and others are subject to change without notice for improvement.
1. Application range
This specification is applied to the LB35B chassis.
2. Requirement for Test
Each part is tested as below without special appointment.
(1) Temperature: 25 °C ± 5 °C(77 °F ± 9 °F), CST: 40 °C ± 5 °C
(2) Relative Humidity: 65 % ± 10 %
(3) Power Voltage
: Standard input voltage (AC 100-240 V~, 50/60 Hz)
* 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 5 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 
4. Model General Specification
* HDMI 1.4 with Deep Color is only apply for FHD Model
No.
Item
Specification
Remarks
1.
Market
NON EU
2.
Broadcasting system
PAL/SECAM B/G/D/K
PAL-I
NTSC-M
3.
Channel Storage
BAND
PAL(BG,I)
NTSC(M)
China(DK)
VHF/UHF
01-C69
2~78
C1~C69
Cable
S1~S47
1~71
S1~S47
4.
Receiving system
Upper Heterodyne
5.
Video Input
PAL, SECAM, NTSC
Rear (2EA)
6.
Component Input
Y/Cb/Cr, Y/Pb/Pr
Rear (1EA)
7.
USB Input
MP3, JPEG,Movie
Side(1EA)
8.
AV Audio Output 
RF/AV/HDMI Audio Output
Rear (1EA)
9.
D-SUB INPUT
S/W Upgrade Only
Rear (1EA)
10. HDMI Input 
HDMI-DTV, Only PCM MODE
Rear (2EA)
11. Audio Input (1EA)
AV&Component 
L/R Input(2EA)
- 7 -
5. Component Video Input (Y, P
B
, P
R
)
No.
Resolution
H-freq(kHz)
V-freq(Hz)
Pixel clock(MHz)
Proposed
1.
720*480
15.73
59.94
13.500
SDTV, DVD 480I(525I)
2.
720*480
15.75
60.00
13.514
SDTV, DVD 480I(525I)
3.
720*576
15.625
50.00
13.500
SDTV, DVD 576I(625I) 50Hz
4.
720*480
31.47
59.94
27.000
SDTV 480P
5.
720*480
31.50
60.00
27.027
SDTV 480P
6.
720*576
31.25
50.00
27.000
SDTV 576P 50Hz
7.
1280*720
44.96
59.94
74.176
HDTV 720P
8.
1280*720
45.00
60.00
74.250
HDTV 720P
9.
1280*720
37.50
50.00
74.25
HDTV 720P 50Hz
10.
1920*1080
28.125
50.00
74.250
HDTV 1080I 50Hz, 
11.
1920*1080
33.72
59.94
74.176
HDTV 1080I
12.
1920*1080
33.75
60.00
74.25
HDTV 1080I
13.
1920*1080
56.25
50
148.5
HDTV 1080P
14.
1920*1080
67.432
59.94
148.350
HDTV 1080P
15.
1920*1080
67.5
60.00
148.5
HDTV 1080P
6. HDMI Input
6.1. PC Mode
* Spec. out but it can be shown the picture at only HDMI/DVI IN 1 via DVI to HDMI Cable
* Monitor Range Limits
  Min Vertical Freq - 58 Hz / Max Vertical Freq - 63 Hz
  Min Horiz. Freq - 28 kHz / Max Horiz. Freq - 68 kHz
  Pixel Clock  - 150 MHz
No.
Resolution
H-freq(kHz)
V-freq.(Hz)
Pixel clock(MHz)
Proposed
Remarks
1.
640×480
31.469
59.94
25.17
VESA(VGA)
2.
800×600
37.879
60.317
40.00
VESA(SVGA)
3.
1024×768
48.363
60.004
65.00
VESA(XGA)
4.
1280×768
47.776
59.87
79.5
VESA(WXGA)
5.
1360×768
47.72
59.799
84.62
VESA(WXGA)
6
1366×768
47.7
60.00
84.62
WXGA
7.
1280×1024
63.595
60.00
108.875
SXGA
8.
1920×1080
66.647
59.988
138.625
WUXGA
- 8 -
No.
Resolution
H-freq(kHz)
V-freq.(kHz)
Pixel clock(MHz) 
Proposed
Remarks
1.
720*480
15.73
59.94
13.500
SDTV, DVD 480I(525I)
Spec. out but display.
2.
720*480
15.75
60.00
13.514
SDTV, DVD 480I(525I)
3.
720*576
15.625
50.00
13.500
SDTV, DVD 576I(625I) 50Hz
4.
720*480
31.47
59.94
27
SDTV 480P
5.
720*480
31.5
60.00
27.027
SDTV 480P
6.
720*576
31.25
50.00
27
SDTV 576P
7.
1280*720
44.96
59.94
74.176
HDTV 720P
8.
1280*720
45
60.00
74.25
HDTV 720P
9.
1280*720
37.5
50.00
74.25
HDTV 720P
10. 1920*1080
28.125
50.00
74.25
HDTV 1080I 
11
1920*1080
33.72
59.94
74.176
HDTV 1080I
12
1920*1080
33.75
60.00
74.25
HDTV 1080I
13
1920*1080
56.25
50.00
148.5
HDTV 1080P 
14
1920*1080
67.432
59.94
148.350
HDTV 1080P
15
1920*1080
67.5
60.00
148.5
HDTV 1080P
16
1920*1080
27
24.00
74.25
HDTV 1080P 
17
1920*1080
33.75
30.00
74.25
HDTV 1080P 
18
1920*1080
26.97
23.97
74.25
HDTV 1080P
19
1920*1080
33.716
29.976
74.25
HDTV 1080P
6.2. DTV Mode
Page of 58
Display

Click on the first or last page to see other 32LN49XX / 32LN4900 (CHASSIS:LB35B) service manuals if exist.