LG 32LT75 / 32LT76 (CHASSIS:LD74A) Service Manual ▷ View online
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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(LCD MODULE)
2. Model General Specification
Item
Specification
Remark
Market
UK, France, Germany, Spain, Sweden, Finland, Italy
Broadcasting system
PAL-BG
UK, France, Germany, Spain, Sweden, Finland, Italy
PAL-DK
PAL-I,I’
DVB-T (ID TV)
Receiving system
Analog : Upper Heterodyne
Digital : COFDM
Scart Jack (2EA)
PAL, SECAM
Scart 1 Jack is Full scart and support RF-OUT(analog)
Scart 2 jack is Half scart and support MNT-OUT.
Video Input (2EA)
PAL, SECAM, NTSC
4 System :
PAL, SECAM, NTSC, PAL60
S-Video Input (1EA)
PAL, SECAM, NTSC
4 System :
PAL, SECAM, NTSC, PAL60
Component Input (1EA)
Y/Cb/Cr, Y/ Pb/Pr
RGB Input
RGB-PC,
RGB-DTV
HDMI Input (2EA)
HDMI-PC
HDMI-DTV & SOUND
Audio Input (4 EA)
PC Audio, Component, AV (2EA)
L/R Input
Item
Specification
Remark
Display Screen Device
32” wide Color Display Module
LCD
Aspect Ratio
16:9
LCD Module
32” TFT WXGA LCD
MAKER : LPL
Operating Environment
Temp. : 0 ~ 40 deg
Humidity : 0 ~ 85%
LGE SPEC
Storage Environment
Temp. : -20 ~ 60 deg
Humidity : 0 ~ 85 %
Input Voltage
100-240V~, 50/60Hz
Power Consumption
Power on (Green)
Total 114.32W (Typ.) (Logic=4.32(4.1)W, Backlight =110W )
St-By (Red) : 1.0 W
Type Size
760.0 x 450.0 x 48.0
Pixel Pitch
0.17025 x 0.51075
Back Light
18 EEFL
Display Colors
16.7M (16,777,216)
Coating
3H, AG
Item
Min
Typ
Max
Unit
Maker
Remark
Luminance
400
500
cd/m
LPL(0RT)32”
-50cm from the surface
(W/O PC mode)
- Full White Pattern
View angle (R/L, U/D)
178/178
degree
32”
Color Coordinate
White
X
Typ.
0.279/0.279/0.279
Typ.
LPL 32”
Y
-0.03
0.292/0.292/0.292
+0.03
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
Contrast ratio
(W/O PC mode)
600
800
32”
LPL(0-RT)
Luminance Variation
1.3
- 7 -
3. Chroma & Brightness (LCD Module-LPL)
4. Component Video Input (Y, P
B
, P
R
)
No
Specification
Proposed
Resolution
H-freq(kHz)
V-freq(Hz)
1
720*480
15.73
60.00
SDTV, DVD 480i
2
720*480
15.63
59.94
SDTV, DVD 480i
3
720*480
31.47
59.94
480p
4
720*576
15.625
50.00
SDTV, DVD 625 Line
5
720*576
31.25
50.00
HDTV 576p
6
1280*720
45.00
50.00
HDTV 720p
7
1280*720
44.96
59.94
HDTV 720p
8
1920*1080
31.25
50.00
HDTV 1080i
9
1920*1080
33.75
60.00
HDTV 1080i
10
1920*1080
33.72
59.94
HDTV 1080i
- 8 -
6. HDMI input (DTV Mode)
5. RGB PC INPUT Mode Table
No
Resolution
H-freq(kHz)
V-freq.(Hz)
Pixel clock(MHz)
Proposed
Remark
1.
720*400
31.468
70.08
28.321
2.
640*480
31.469
59.94
25.17
VESA
Input 848*480 60Hz, 852*480 60Hz
37.684
75.00
31.50
--> 640*480 60Hz Display
3
800*600
37.879
60.31
40.00
VESA
46.875
75.00
49.50
4
832*624
49.725
74.55
57.283
Macintosh
5
1024*768
48.363
60.00
65.00
VESA(XGA)
56.470
70.00
75.00
60.123
75.029
78.75
6
1280*768
47.78
59.87
79.5
WXGA
7
1360*768
47.72
59.8
84.75
WXGA
8
1366*768
47.56
59.6
84.75
WXGA
9
1280*1024
63.595
60.0
108.875
SXGA
FHD Model only
10
1400*1050
65.160
60.0
122.50
SXGA
FHD Model only
11
1600*1200
74.077
60.0
130.375
UXGA
Reduced Blanking Timing, FHD Model only
Input 1920*1200 60Hz -> 1600*1200 60Hz Display
12
1920*1080
66.647
59.988
138.625
WUXGA
Reduced Blanking Timing
No
Resolution
H-freq(kHz)
V-freq.(Hz)
Pixel clock(MHz)
Proposed
Remark
1.
720*480
31.47
59.94
27.00
SDTV 480P(4:3)
PC mode -> 640*480 60Hz Display
2.
720*480
31.50
60
27.027
SDTV 480P(4:3)
3.
640*480
31.469
59.94
25.175
SDTV 480P(4:3)
4.
640*480
31.469
60.00
25.20
SDTV 480P(4:3)
5.
720*480
31.47
59.94
27.000
SDTV 480P(16:9)
6.
720*480
31.50
60.00
27.027
SDTV 480P(16:9)
7.
720*576
31.25
50.00
27.000
SDTV 576P
8.
1280*720
37.50
50.00
74.176
HDTV 720P
9.
1280*720
44.96
59.94
74.176
HDTV 720P
PC mode -> 1280*720 60Hz Display
10.
1280*720
45.00
60.00
74.250
HDTV 720P
11
1920*1080
33.72
59.94
74.176
HDTV 1080I
12
1920*1080
33.75
60.00
74.250
HDTV 1080I
13
1920*1080
28.125
50.00
74.250
HDTV 1080I 50Hz
14
1920*1080
27.000
24.00
74.250
HDTV 1080P 24Hz
15
1920*1080
56.250
50
148.500
HDTV 1080P 50Hz
16
1920*1080
67.433
59.94
148.352
HDTV 1080P
PC mode -> 1920*1080 60Hz Display
17
1920*1080
67.500
60
148.500
HDTV 1080P
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