LG 37LB1R (CHASSIS:ML-051B) 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.
1.General Specification(TV)
No
Item
Specification
Remark
1.
Video input applicable system
PAL-D/K, B/G, I, NTSC-M, SECAM
NTSC 4.43
2.
Receivable Broadcasting System
1) PAL/SECAM BG
(ZE/TE)
2) PAL/SECAM DK
EU/Non-EU
3) PAL I/I
(PAL Market)
4) SECAM L/L'
5) NTSC M
6) PAL-N/M
6),7) South America Market
7) NTSC M
7) Except South America NTSC Market (ME)
3.
RF Input Channel
VHF : E2 ~ E12
PAL
UHF : E21 ~ E69
CATV : S1 ~ S20
HYPER : S21~ S47
L/L' : B, C, D
FRANCE
VHF : 2~13
NTSC
UHF : 14~69
CATV : 1~125
VHF Low : 1 ~ M10
JAPAN
VHF High : 4~S22
UHF : S23~62
4.
Input Voltage
AC 100 ~ 240 V/50Hz, 60Hz
5.
Market
Worldwide
6.
Picture Size
800.4mm
31.51inch(32LB1R)
940.3mm
37.02 inch(37LB1R)
7.
Tuning System
FVS 100 program
PAL, 200 PR.(Option)
FS
NTSC
8.
Operating Environment
1) Temp : 0 ~ 40 deg
2) Humidity : 10~90 %
9.
Storage Environment
3) Temp : -20 ~ 50 deg
4) Humidity : 10~90 %
10.
Display
LCD Module
LPL
- 7 -
2. General Specification
No
Item
Specification
Remark
1
Panel
32", 37" TFT WXGA LCD
2
Frequency range
H : 31 ~ 61Khz
PC Input
V : 56 ~ 75Hz
3
Control Function
1) Contrast/Brightness
2) H-Position / V-Position
3) Tracking : Clock / Phase
4) Auto Configure
5) Reset
4
Component Jack
1 : Y
Middle east / NTSC Area
3 : Pb
5 : Pr
7 : Line1 Ready
9 : LINE2
11: LINE3
13: Line3 Ready
D4 Jack(525i, 525p, 750p,1125i)
2 : Y GND
JAPAN Only
4 : Pb GND
6 : Pr GND
8 : LINE1
10:Line2 Ready
12:SWITCH GND
14: SWITCH
5
H/V-Sync
Video
Power consumption
LED
Power ON
-
-
≤
145W(32")
≤
180W(37")
Green
Stand by
≤
3.0W
Red
DPMS Mode
ON/OFF
OFF
≤
30W
Green
Power off
-
-
-
*
6
LCD Module
Outline
32"
760.0x450.0x48.0(mm)
(H)x(V)x(D)
Dimension
37"
877.0 x 516.8 x 55.5(mm)
Pixel Pitch
32"
0.1702 x 0.5107 x RGB(mm)
37"
0.200 x 0.600 x RGB
Pixel Format
1366 horiz. By 768 vert.
Pixels RGB strip arrangement
Coating
Hard coating(3H), Anti-glare
reatment of the front polarizer,
Back Light
32"
20EEFL
37"
16CCFL
- 8 -
3.Optical Feature(LCD Module)
Item
Remark
Specification
Viewing Angle<CR
10>
Luminance
Contrast Ratio
CIE Color Coordinates
Typical
MAX/MIN
ALL white/All back
LPL
R/L, U/D
Luminance(cd/
)
Variation
CR
CR
D
(With Al)
Typ
176, 176
500
600
1200
0.285
0.293
0.640
0.341
0.287
0.610
0.146
0.069
WHITE
RED
GREEN
BLUE
W
x
W
y
R
R
y
G
x
G
y
B
x
B
y
Typ.
Typ.
Typ.
Typ.
Typ.
Typ.
Typ.
Typ.
No.
1
2
3
4
4.Component Video Input (Y, P
B
, P
R
)
No
Specification
Proposed
Resolution
H-freq(kHz)
V-freq(Hz)
1.
640x480
15.73
60
SDTV, DVD 480i
ZE, TE, ME
2.
640x480
15.63
59.94
SDTV, DVD 480i
ZE, TE, ME
3.
720x480
31.47
59.94
EDTV 480p
TE, ME
4.
720x576
15.625
50.00
SDTV, DVD 625 Line
ZE, TE, ME
5.
720x576
31.25
50.00
HDTV 576p
TE, ME
6.
1280x720
45.00
60.00
HDTV 720p
TE, ME
7.
1280x720
44.96
59.94
HDTV 720p
TE, ME
8.
1920x1080
31.25
50.00
HDTV 1080i 50Hz (AU Ver.)
TE, ME
9.
1920x1080
33.75
60.00
HDTV 1080i 60Hz (ATSC)
TE, ME
10.
1920x1080
33.72
59.94
HDTV 1080i 59.94Hz
TE, ME
5. PC INPUT Mode Table
No
Resolution
H-freq(kHz)
V-freq.(Hz)
Pixel clock(MHz)
Proposed
Analog RGB, Digital RGB
1
720x400
31.468
70.8
28.321
2
640x480
31.469
59.94
25.17
VESA
37.684
75.00
31.5
VESA
3
800x600
37.879
60.31
40.00
VESA
46.875
75
49.5
VESA
4
832x624
49.725
74.55
57.283
5
1024x768
48.363
60.00
65.00
VESA(XGA)
56.47
70.00
75.00
VESA(XGA)
60.123
75.029
78.75
VESA(XGA)
6
1280x768
47.776
59.870
79.50
VESA(WXGA)
7
1360x768
47.720
59.799
84.75
VESA(WXGA)
8
1366x768
47.720
59.799
84.75
Supported
Min
400
800
Typ.
-0.03
Max
1.3
Typ.
+0.03
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