32LV3700-ZC, 32LV370S, 32LV375G-ZC, 32LV375S-ZC, 32LV375W-ZC (CHASSIS:LD12B) — LG TV Service Manual (repair manual)

Model
32LV3700-ZC 32LV370S 32LV375G-ZC 32LV375S-ZC 32LV375W-ZC (CHASSIS:LD12B)
Pages
74
Size
12.16 MB
Type
PDF
Document
Service Manual
Brand
Device
TV / LCD
File
32lv3700-zc-32lv370s-32lv375g-zc-32lv375s-zc-32lv3.pdf
Date

View LG 32LV3700-ZC / 32LV370S / 32LV375G-ZC / 32LV375S-ZC / 32LV375W-ZC (CHASSIS:LD12B) Service Manual online

LED LCD TV
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
CHASSIS : LD12B
MODEL: 32LV3700
32LV3700-ZC
MODEL: 
32LV375G/S/W
32LV375G/S/W-ZC
P/NO : MFL67002301 (1101-REV00)
- 2 -
CONTENTS
CONTENTS .............................................................................................. 2
PRODUCT SAFETY ................................................................................. 3
SPECIFICATION ....................................................................................... 4
ADJUSTMENT INSTRUCTION ................................................................ 8
BLOCK DIAGRAM.................................................................................. 14
EXPLODED VIEW .................................................................................. 15
SCHEMATIC CIRCUIT DIAGRAM ..............................................................
- 3 -
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.
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.
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.
If any fuse (or Fusible Resistor) in this TV receiver is blown,
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.
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. 
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.
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.
Leakage Current Hot Check circuit
1.5 Kohm/10W
To Instrument’s
exposed 
METALLIC PARTS
Good Earth Ground
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
- 4 -
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
: 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 
Page of 74
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Here you can view online or download LG 32LV3700-ZC / 32LV370S / 32LV375G-ZC / 32LV375S-ZC / 32LV375W-ZC (CHASSIS:LD12B) Service Manual in pdf. This Service Manual can help you recover, restore, fix, disassemble and repair LG 32LV3700-ZC / 32LV370S / 32LV375G-ZC / 32LV375S-ZC / 32LV375W-ZC (CHASSIS:LD12B) LCD. Information contained in LG 32LV3700-ZC / 32LV370S / 32LV375G-ZC / 32LV375S-ZC / 32LV375W-ZC (CHASSIS:LD12B) service manual (repair manual) typically includes:

  • Disassembly, troubleshooting, programming, maintenance, remote, adjustment, installation and setup instructions.
  • Schematics, wiring and block diagrams.
  • Printed wiring boards (PWB) and printed circuit boards (PCB).
  • Parts list (bill of materials).