42PG20R-TA (CHASSIS:PP81A) — LG TV Service Manual (repair manual)

Model
42PG20R-TA (CHASSIS:PP81A)
Pages
28
Size
10.36 MB
Type
PDF
Document
Service Manual
Brand
Device
TV / Plasma
File
42pg20r-ta-chassis-pp81a.pdf
Date

View LG 42PG20R-TA (CHASSIS:PP81A) Service Manual online

PLASMA TV
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
CHASSIS : PP81A
MODEL : 42PG20R
42PG20R-TA
- 2 -
CONTENTS
CONTENTS .............................................................................................. 2
SAFETY PRECAUTIONS ..........................................................................3
SPECIFICATION ........................................................................................4
ADJUSTMENT INSTRUCTION .................................................................6
TROUBLE SHOOTING ............................................................................16
BLOCK DIAGRAM...................................................................................23
EXPLODED VIEW .................................................................................. 24
SVC. SHEET  ...............................................................................................
PRINTED 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 Replacement Parts List. 
It is essential that these special safety parts should be replaced with the same components as recommended in this manual to prevent
X-RADIATION, 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 monitor is blown, replace it
with the specified.
When replacing a high wattage resistor (Oxide Metal Film Resistor,
over 1W), keep the resistor 10mm away from PCB.
Keep wires away from high voltage or high temperature parts.
Due  to  high  vacuum  and  large  surface  area  of  picture  tube,
extreme care should be used in handling the Picture Tube.
Do not lift the Picture tube by it's Neck.
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 1MΩ and 5.2MΩ. 
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  1.5K/10watt  resistor  in  parallel  with  a  0.15uF  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
0.5mA.
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
0.15uF
- 4 -
SPECIFICATIONS
NOTE : Specifications and others are subject to change without notice for improvement.
V
Application Range
This spec is applied to the 42” 
PLASMA TV used PP81A Chassis.
Specification
Each part is tested as below without special appointment.
1) Temperature : 25±5°C (77±9°F), CST : 40±5
2) Relative Humidity: 65±10%
3) Power Voltage: Standard Input voltage (100-240V~, 50/60Hz)
* Standard Voltage of each product is marked by models.
4) Specification and performance of each parts are followed each drawing and specification by part number in accordance with SBOM.
5) The receiver must be operated for about 20 minutes prior to the adjustment.
V
Test Method
1) Performance : LGE TV test method followed.
2) Demanded other specification 
Safety : CE, IEC specification
EMC
: CE, IEC
V
General Specification ( 42” XGA Module)
Display Screen Device
Aspect Ratio
PDP Module
Operating Environment
Storage Environment
Input Voltage
1
2
3
4
5
6
No
Item
Specification
Remark
42” Wide Color Display Module
16:9
PDP42PG1, 
RGB Closed Type
1)Temp.
: 0~60deg
2)Humidity : 20~80%
3)Temp.
: -20~60deg
4)Humidity : 10~90%
100-240V~, 50/60Hz
Plasma Display Panel
Glass Filter
LGE SPEC.
Maker : LGIT, Sansung
Chassis
PP81A
42PG20R-TA
Non-EU
LG
Model Name
Market
Brand
Remark
42PG20R-TA
Safety : IEC/EN60065, 
EMI : CISPR13
Non-EU
Model
Appliance
Market
TEST
Remark
Page of 28
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Here you can view online or download LG 42PG20R-TA (CHASSIS:PP81A) Service Manual in pdf. This Service Manual can help you recover, restore, fix, disassemble and repair LG 42PG20R-TA (CHASSIS:PP81A) Plasma. Information contained in LG 42PG20R-TA (CHASSIS:PP81A) 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).