LG 55LM4610 / 55LM4650 (CHASSIS:LB21B) 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 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 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 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 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 LB21B 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
No.
Item
Specification
Remarks
1.
Market
Austrailia, New Zealand, Singapore, Malaysia,
Vietnam, Indonesia,
only Analog for A-ASIA
2.
Broadcasting system
1) PAL/SECAM-B/G/D/K
2) PAL-I/II
3) NTSC-M
4) DVB-T
PAL for NZ/SG
3.
Channel Storage
ATV - 135EA, DTV - 1000EA
4.
Receiving system
Analog : Upper Heterodyne
Digital : COFDM(DVB-T)
▪ DVB-T
- Guard Interval(Bitrate_Mbit/s)
1/4, 1/8, 1/16, 1/32
- Modulation : Code Rate
QPSK : 1/2, 2/3, 3/4, 5/6, 7/8
16-QAM : 1/2, 2/3, 3/4, 5/6, 7/8
64-QAM : 1/2, 2/3, 3/4, 5/6, 7/8
5.
Video(Composite) Input PAL, SECAM, NTSC
4 System : PAL, SECAM, NTSC, PAL60
6.
Component Input
Y/Cb/Cr, Y/Pb/Pr
7.
RGB Input
RGB-PC
Analog (D-sub 15PIN)
8.
HDMI Input
HDMI1-DTV/DVI
HDMI2-DTV/DVI
HDMI3-DTV
PC
- Non 3D HD/FHD Model : HDMI version 1.3
- 3D Model : HDMI version 1.4a
Support HDCP
9.
Audio Input
RGB/DVI audio, Component, AV
10. SPDIF out
SPDIF out
11. USB
For My Media(Movie/Photo/Music List) or SVC
12. LAN
DLNA
Only LB21B
- 7 -
5. Component Video Input (Y, P
B
, P
R
)
6. RGB (PC)
No.
Resolution
H-freq(kHz)
V-freq(Hz)
Pixel clock(MHz)
Proposed
1
720*480i
15.73
59.94
13.500
SDTV, DVD 480I(525I)
2
720*480i
15.73
60.00
13.514
SDTV, DVD 480I(525I)
3
720*576i
15.625
50.00
13.500
SDTV, DVD 576I(625I) 50Hz
4
720*480p
31.47
59.94
27.000
SDTV 480P
5
720*480p
31.50
60.00
27.027
SDTV 480P
6
720*576p
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
26.97
23.976
63.296
HDTV 1080P
14
1920*1080
27.00
24.000
63.36
HDTV 1080P
15
1920*1080
33.71
29.97
79.120
HDTV 1080P
16
1920*1080
33.75
30.00
79.20
HDTV 1080P
17
1920*1080
56.25
50
148.5
HDTV 1080P
18
1920*1080
67.432
59.94
148.350
HDTV 1080P
19
1920*1080
67.5
60.00
148.5
HDTV 1080P
No.
Resolution
H-freq(kHz)
V-freq.(Hz)
Pixel clock(MHz)
Proposed
Remarks
1
640*350
31.468
70.09
25.17
EGA
2
720*400
31.469
70.09
28.32
DOS
3
640*480
31.469
3.
640*480
31.469
4
800*600
37.879
60.317
40
VESA(SVGA)
5
1024*768
48.363
60.004
65
VESA(XGA)
6
1360*768
47.712
60.015
84.75
VESA(WXGA)
7
1920*1080
66.587
59.934
138.50
WUXGA (Reduced Blanking)
Only FHD Model
- 8 -
7. HDMI Input
(1) DTV Mode
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
26.97
23.976
63.296
HDTV 1080P
14
1920*1080
27.00
24.000
63.36
HDTV 1080P
15
1920*1080
33.71
29.97
79.120
HDTV 1080P
16
1920*1080
33.75
30.00
79.20
HDTV 1080P
17
1920*1080
56.25
50.00
148.5
HDTV 1080P
18
1920*1080
67.432
59.94
148.350
HDTV 1080P
19
1920*1080
67.5
60.00
148.5
HDTV 1080P
(2) PC Mode
No.
Resolution
H-freq(kHz)
V-freq.(Hz)
Pixel clock(MHz)
Proposed
Remarks
1
640*350
31.468
70.09
25.17
EGA
2
720*400
31.469
70.09
28.32
DOS
3
640*480
31.469
59.94
25.17
VESA(VGA)
4
800*600
37.879
60.317
40
VESA(SVGA)
5
1024*768
48.363
60.004
65
VESA(XGA)
6
1152*864
54.348
60.053
80.002
VESA(VGA)
7
1360*768
47.712
60.015
84.75
VESA(WXGA)
8
1280*1024
63.981
60.02
109.00
SXGA
Only FHD Model
(Support to HDMNI-PC)
9
1920*1080
67.5
60
158.40
WUXGA (Reduced Blanking)
Only FHD Model
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