View LG 55LS4500 (CHASSIS:LA25C) Service Manual online
P/NO : MFL67454211 (1208-REV00)
CHASSIS : LA25C
MODEL : 55LS4500
55LS4500-UD
CAUTION
BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
LED LCD TV
SERVICE MANUAL
- 2 -
CONTENTS
CONTENTS .............................................................................................. 2
PRODUCT SAFETY ................................................................................. 3
SPECIFICATION ....................................................................................... 4
ADJUSTMENT INSTRUCTION ................................................................ 6
TROUBLESHOOTING .............................................................................13
BLOCK DIAGRAM ...................................................................................24
EXPLODED VIEW .................................................................................. 25
SCHEMATIC CIRCUIT DIAGRAM ..............................................................
- 3 -
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 M
Ω 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
IMPORTANT SAFETY NOTICE
SAFETY PRECAUTIONS
- 4 -
SPECIFICATION
NOTE : Specifications and others are subject to change without notice for improvement.
1. Application range
This spec sheet is applied LCD TV with LA25A/B/C chassis
2. Test condition
Each part is tested as below without special notice.
1) Temperature : 25 ºC ± 5 ºC(77 ± 9 ºF), CST : 40 ± 5 ºC
2) Relative Humidity: 65 % ± 10 %
3) Power Voltage
- AC 110-240 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 : UL, CSA, IEC specification
- EMC: FCC, ICES, IEC specification
4. General Specification
No
Item
Specification
Remark
1
Receiving System
1) ATSC / NTSC-M
2
Available Channel
1) VHF : 02~13
2) UHF : 14~69
3) DTV : 02-69
4) CATV : 01~135
5) CADTV : 01~135
2) UHF : 14~69
3) DTV : 02-69
4) CATV : 01~135
5) CADTV : 01~135
3
Input Voltage
1) AC 100 ~ 240V 50/60Hz
120V, 50/60Hz on the label (USA)
4
Market
NORTH AMERICA
5
Screen Size
32/37/42 inch Wide (1920 × 1080)
FHD + 60Hz 42LS3400-UA
22/26/32 inch Wide (1366 × 768)
HD + 60Hz
32LS3400-UA
6
Aspect Ratio
16:9
7
Tuning System
FS
8
Module(Direct LED)
LC320DXN-SER2
LGD
32LS3400-UA
LC420DUN-SER2
LGD
42LS3400-UA
9
Operating Environment
1) Temp : 0 ~ 40 deg
2) Humidity : ~ 80 %
10 Storage Environment
1) Temp : -20 ~ 60 deg
2) Humidity : ~ 85 %