55LM4600 (CHASSIS:LT21B) — LG TV Service Manual (repair manual)

Model
55LM4600 (CHASSIS:LT21B)
Pages
46
Size
5.9 MB
Type
PDF
Document
Service Manual
Brand
Device
TV / LCD
File
55lm4600-chassis-lt21b.pdf
Date

View LG 55LM4600 (CHASSIS:LT21B) Service Manual online

P/NO : MFL67362821 (1205-REV00)
CHASSIS : LT21B
MODEL : 55LM4600   
55LM4600-DB
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 .............................................................. 10
SCREW ASSEMBLY WORKING GUIDE ............................................... 19
TROUBLE SHOOTING ............................................................................20
BLOCK DIAGRAM .................................................................................. 26
EXPLODED VIEW  .................................................................................. 27
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 LT21B/C Chassis
2. Test condition
Each part is tested as below without special notice.
1) Temperature : 25 ºC ± 5 ºC (77 ºF ± 9 ºF), CST : 40 ºC±5 ºC
2) Relative Humidity: 65 % ± 10 %
3) Power Voltage
- Taiwan : 110V 60Hz
- Colombia : [email protected]/60Hz)
* 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 
- 5 -
4. General Specification
No
Item
Specification
Remark
1.
Screen Size
31.55 inch
LC320EUN-SEM2
31.50 inch
T320HVN01.0(60Hz/FHD/AUO)
31.51 inch
LC320DXN-SER2(60Hz/HD)
31.55 inch
LC320WUN-SCA2(60Hz/FHD/EEFL)
31.51 inch
LC320EXN-SEA2(60Hz/HD)
31.50 inch
T320XVN01.1(60Hz/HD/AUO)
31.51 inch
LC320WXN-SCA2(10 years module)
31.51 inch
LC320DXN-SEU2(60Hz/FHD)
31.55inch
LC320EUN-SEF2(T120)
42.02 inch
LC420DUN_SEU2(60Hz/FHD)
42.92 inch
LC420EUE-SEF1(T120)
46.96 inch
LC470EUE-SEF1(T120)
42.02 inch
LC420WUE-SCA2(60Hz/FHD/EEFL)
42.02 inch
T420HVN02.1(60Hz/FHD/EEFL/AUO)
54.64 inch
LC550EUE-SEF1(T120)
46.96 inch
LC470EUE-SEM1(60Hz/FHD)
42.02 inch
LC420EUE-SEM1(60Hz/FHD)
42.02 inch
LC420DUN_SER2(60Hz/FHD)
42.00 inch
T420HVN01.1(60Hz/FHD/AUO)
2.
Aspect Ratio
16:9
All
3.
LCD Module
31.55” Color WUXGA TFT-LCD Module
LC320EUN-SEM2
31.50” Color WUXGA TFT-LCD Module
T320HVN01.0(60Hz/FHD/AUO)
31.55” Color WUXGA TFT-LCD Module
LC320WUN-SCA2(60Hz/FHD/EEFL)
31.51” Color WXGA TFT-LCD Module
LC320EXN-SEA2(60Hz/HD)
31.51” Color WXGA TFT-LCD Module
LC320DXN-SER2(60Hz/HD)
31.51” Color WUXGA TFT-LCD Module
LC320DXN-SEU2(60Hz/FHD)
31.50” Color WXGA TFT-LCD Module
T320XVN01.1(60Hz/HD/AUO)
31.55” Color WXGA TFT-LCD Module
LC320WXN-SCA2(10 years module)
31.55” Color WUXGA TFT-LCD Module
LC320EUN-SEF2(T120)
42.02” Color WUXGA TFT-LCD Module
LC420DUN_SEU2(60Hz/FHD)
46.96” Color WUXGA TFT-LCD Module
LC470EUE-SEF1(T120)
42.02” Color WUXGA TFT-LCD Module
LC420EUE-SEF1(T120)
54.64” Color WUXGA TFT-LCD Module
LC550EUE-SEF1(T120)
46.96” Color WUXGA TFT-LCD Module
LC470EUE-SEM1(60Hz/FHD)
42.02” Color WUXGA TFT-LCD Module
LC420DUN_SER2(60Hz/FHD)
42.02” Color WUXGA TFT-LCD Module
LC420EUE-SEM1(60Hz/FHD)
42.00” Color WUXGA TFT-LCD Module
T420HVN01.1(60Hz/FHD/AUO)
42.02” Color WUXGA TFT-LCD Module
LC420WUE-SCA2(60Hz/FHD/EEFL)
42.02” Color WUXGA TFT-LCD Module
T420HVN02.1(60Hz/FHD/EEFL/AUO)

Download LG 55LM4600 (CHASSIS:LT21B) Service Manual (Repair Manual)

Here you can view online or download LG 55LM4600 (CHASSIS:LT21B) Service Manual in pdf. This Service Manual can help you recover, restore, fix, disassemble and repair LG 55LM4600 (CHASSIS:LT21B) LCD. Information contained in LG 55LM4600 (CHASSIS:LT21B) 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).