LG 32LV3700-ZC / 32LV370S / 32LV375G-ZC / 32LV375S-ZC / 32LV375W-ZC (CHASSIS:LD12B) Service Manual ▷ View online
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SAFETY PRECAUTIONS
Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by in the
Schematic Diagram and Exploded View.
It is essential that these special safety parts should be replaced with the same components as recommended in this manual to prevent
Shock, Fire, or other Hazards.
Do not modify the original design without permission of manufacturer.
Schematic Diagram and Exploded View.
It is essential that these special safety parts should be replaced with the same components as recommended in this manual to prevent
Shock, Fire, or other Hazards.
Do not modify the original design without permission of manufacturer.
General Guidance
An isolation Transformer should always be used during the
servicing of a receiver whose chassis is not isolated from the AC
power line. Use a transformer of adequate power rating as this
protects the technician from accidents resulting in personal injury
from electrical shocks.
servicing of a receiver whose chassis is not isolated from the AC
power line. Use a transformer of adequate power rating as this
protects the technician from accidents resulting in personal injury
from electrical shocks.
It will also protect the receiver and it's components from being
damaged by accidental shorts of the circuitry that may be
inadvertently introduced during the service operation.
damaged by accidental shorts of the circuitry that may be
inadvertently introduced during the service operation.
If any fuse (or Fusible Resistor) in this TV receiver is blown,
replace it with the specified.
replace it with the specified.
When replacing a high wattage resistor (Oxide Metal Film Resistor,
over 1 W), keep the resistor 10 mm away from PCB.
over 1 W), keep the resistor 10 mm away from PCB.
Keep wires away from high voltage or high temperature parts.
Before returning the receiver to the customer,
always perform an AC leakage current check on the exposed
metallic parts of the cabinet, such as antennas, terminals, etc., to
be sure the set is safe to operate without damage of electrical
shock.
metallic parts of the cabinet, such as antennas, terminals, etc., to
be sure the set is safe to operate without damage of electrical
shock.
Leakage Current Cold Check(Antenna Cold Check)
With the instrument AC plug removed from AC source, connect an
electrical jumper across the two AC plug prongs. Place the AC
switch in the on position, connect one lead of ohm-meter to the AC
plug prongs tied together and touch other ohm-meter lead in turn to
each exposed metallic parts such as antenna terminals, phone
jacks, etc.
If the exposed metallic part has a return path to the chassis, the
measured resistance should be between 1 MΩ and 5.2 MΩ.
When the exposed metal has no return path to the chassis the
reading must be infinite.
An other abnormality exists that must be corrected before the
receiver is returned to the customer.
electrical jumper across the two AC plug prongs. Place the AC
switch in the on position, connect one lead of ohm-meter to the AC
plug prongs tied together and touch other ohm-meter lead in turn to
each exposed metallic parts such as antenna terminals, phone
jacks, etc.
If the exposed metallic part has a return path to the chassis, the
measured resistance should be between 1 MΩ and 5.2 MΩ.
When the exposed metal has no return path to the chassis the
reading must be infinite.
An other abnormality exists that must be corrected before the
receiver is returned to the customer.
Leakage Current Hot Check
(See below Figure)
Plug the AC cord directly into the AC outlet.
Do not use a line Isolation Transformer during this check.
Connect 1.5 K / 10 watt resistor in parallel with a 0.15 uF capacitor
between a known good earth ground (Water Pipe, Conduit, etc.)
and the exposed metallic parts.
Measure the AC voltage across the resistor using AC voltmeter
with 1000 ohms/volt or more sensitivity.
Reverse plug the AC cord into the AC outlet and repeat AC voltage
measurements for each exposed metallic part. Any voltage
measured must not exceed 0.75 volt RMS which is corresponds to
0.5 mA.
In case any measurement is out of the limits specified, there is
possibility of shock hazard and the set must be checked and
repaired before it is returned to the customer.
Connect 1.5 K / 10 watt resistor in parallel with a 0.15 uF capacitor
between a known good earth ground (Water Pipe, Conduit, etc.)
and the exposed metallic parts.
Measure the AC voltage across the resistor using AC voltmeter
with 1000 ohms/volt or more sensitivity.
Reverse plug the AC cord into the AC outlet and repeat AC voltage
measurements for each exposed metallic part. Any voltage
measured must not exceed 0.75 volt RMS which is corresponds to
0.5 mA.
In case any measurement is out of the limits specified, there is
possibility of shock hazard and the set must be checked and
repaired before it is returned to the customer.
Leakage Current Hot Check circuit
1.5 Kohm/10W
To Instrument’s
exposed
METALLIC PARTS
exposed
METALLIC PARTS
Good Earth Ground
such as WATER PIPE,
CONDUIT etc.
such as WATER PIPE,
CONDUIT etc.
AC Volt-meter
When 25A is impressed between Earth and 2nd Ground
for 1 second, Resistance must be less than 0.1
*Base on Adjustment standard
IMPORTANT SAFETY NOTICE
0.15 uF
Ω
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SPECIFICATION
NOTE : Specifications and others are subject to change without notice for improvement.
1. Application range
This specification is applied to the LCD TV used LD12B chassis.
2. Requirement for Test
Each part is tested as below without special appointment.
1) Temperature: 25 ºC ± 5 ºC(77 ºF ± 9 ºF), CST: 40 ºC ± 5 ºC
2) Relative Humidity : 65 % ± 10 %
3) Power Voltage
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.
* 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
2) Demanded other specification
- Safety : CE, IEC specification
- EMC :CE, IEC
- EMC :CE, IEC
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4. Model General Specification
No. Item
Specification
Remarks
1 Market
EU(PAL
Market-36Countries)
DTV & Analog (Total 36 countries)
DTV (MPEG2/4, DVB-T) : 31 countries
(England/Italy/Germany/France/Spain/Sweden/Finland/Netherlands/Belgium/Luxemburg/
Greece/Denmark/Czech/Austria /Hungary/Swiss/Croatia/Turkey/Norway/Slovenia/Poland/
Ukraine/Portugal/Ireland/Moroco/Latvia/Estonia/Lithania/Rumania/Russia/Slovakia)
DTV (MPEG2/4, DVB-T2): 5 countries
(England/Sweden/Finland/Denmark/Norway)
DTV (MPEG2/4, DVB-C): 10 countries
(Sweden/Finland/Denmark/Norway/Austria/Swiss/Germany/Netherlands/Hungary/Slovenia)
Analog Only - 5 countries
(Bosnia/Serbia/Bulgaria/Albania/Kazakhstan)
2 Broadcasting system
1) PAL-BG
- DVB-T2/S is supported in specific models.
2) PAL-DK
1. DVB-T2 : Model name : xxxxxxxT
3) PAL-I/I’
2. DVB-S : Model name : xxxxxxxS
4) SECAM L/L’
- SECAM L/L’ is not supported in DVB-T2 models.
5) DVB-T/C
6) DVB-T2
7) DVB-S
3 Receiving system
Analog : Upper Heterodyne
G
DVB-T
Digital : COFDM , QAM
- 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
G
DVB-C
- Symbolrate : 4.0Msymbols/s to 7.2Msymbols/s
- Modulation : 16QAM, 64-QAM, 128-QAM and 256-QAM
G
DVB-T2
- Guard Interval(Bitrate_Mbit/s)
1/4,1/8,1/16,1/32,1/128,19/128,19/256,
- Modulation : Code Rate
QPSK : 1/2, 2/5, 2/3, 3/4, 5/6
16-QAM : 1/2, 2/5, 2/3, 3/4, 5/6
64-QAM : 1/2, 2/5, 2/3, 3/4, 5/6
256-QAM : 1/2, 2/5, 2/3, 3/4, 5/6
G
DVB-S
G
DVB-S2
4 Scart Jack (1EA)
PAL, SECAM
Scart Jack is Full scart and support RF-OUT(analog & DTV)
SECAM is not supported in DVB-T2 models.
5
Video Input RCA(1EA) PAL, SECAM, NTSC
4System : PAL, SECAM, NTSC, PAL60
SECAM is not supported in DVB-T2 models.
6
Component Input(1EA) Y/Cb/Cr, Y/Pb/Pr
7
RGB Input
RGB-PC
Analog(D-SUB 15PIN)
8
HDMI Input (3EA)
HDMI1-DTV (DVI)
PC(HDMI version 1.3)
HDMI2-DTV
Support HDCP
HDMI3-DTV
9
Audio Input (3EA)
RGB/DVI Audio, Component, AV
L/R Input
10 SDPIF out (1EA)
SPDIF out
11 Earphone out (1EA)
Antenna, AV1, AV2, AV3, Component,
RGB, HDMI1, HDMI2, HDMI3, USB
12 USB (1EA)
EMF
JPEG, MP3
For SVC (download)
DivX HD
- 6 -
5. Component Video Input (Y, C
B
/P
B
, C
R
/P
R
)
No.
Specification
Remark
Resolution
H-freq(kHz)
V-freq(Hz)
1.
720x480 15.73
60.00
SDTV,DVD
480i
2.
720x480 15.63
59.94
SDTV,DVD
480i
3.
720x480
31.47
59.94 480p
4.
720x480
31.50
60.00 480p
5.
720x576
15.625
50.00
SDTV,DVD 625 Line
6.
720x576 31.25
50.00
HDTV
576p
7.
1280x720
45.00
50.00 HDTV
720p
8.
1280x720
44.96
59.94 HDTV
720p
9.
1280x720 45.00
60.00
HDTV
720p
10.
1920x1080 31.25
50.00
HDTV
1080i
11.
1920x1080
33.75
60.00 HDTV
1080i
12.
1920x1080 33.72
59.94
HDTV
1080i
13.
1920x1080 56.250
50
HDTV
1080p
14.
1920x1080
67.5 60 HDTV
1080p
No.
Specification
Proposed
Remarks
Resolution
H-freq(kHz)
V-freq(Hz)
Pixel Clock(MHz)
1.
720*400
31.468
70.08
28.321
For only DOS mode
2.
640*480
31.469
59.94
25.17
VESA
Input 848*480 60 Hz, 852*480 60 Hz
-> 640*480 60 Hz Display
3.
800*600
37.879
60.31
40.00 VESA
4.
1024*768 48.363 60.00
65.00 VESA(XGA)
5.
1280*768 47.78 59.87
79.5
WXGA
6.
1360*768 47.72
59.8
84.75 WXGA
7.
1920*1080 66.587
59.93
138.625 WUXGA
FHD
model
6. RGB Input (PC)
