50PC5DC-UL (CHASSIS:PA64A) - LG TV Service Manual (repair manual)

BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

- 2 -

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 lsolation 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 circuitary that may be
inadvertently introduced during the service operation.

If any fuse (or Fusible Resistor) in this monitor is blown, replace it
with the same specified type.

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.

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 positioin, 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 esposed 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 sepcified, 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

CANADA: LG Electronics Canada, Inc. 550 Matheson

Boulevard East Mississauga, Ontario L4Z 4G3

USA      : LG Customer Interactive Center

P.O.Box 240007, 201 James Record Road Huntsville,
AL 35824
Digital TV Hotline  1-800-243-0000

1.5 Kohm/10W

To Instrument's
exposed 
METALLIC PARTS

Good Earth Ground
such as WATER PIPE,
CONDUIT etc.

AC Volt-meter

IMPORTANT SAFETY NOTICE

0.15uF

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ADJUSTMENT INSTRUCTIONS ..........................................4

BLOCK DIAGRAM...............................................................13

EXPLODED VIEW...............................................................15

EXPLODED VIEW PARTS LIST .........................................16

REPLACEMENT PARTS LIST ............................................17

SCHEMATIC DIAGRAM..........................................................

PRINTED CIRCUIT BOARDS .................................................

- 4 -

These instructions are applied to all of the Plasma TV, 
PA64A.

(1) Because this is not a hot chassis, it is not necessary to use

an isolation transformer. However, the use of isolation
transformer will help protect test equipment.

(2) Adjustments must be done in the correct order.
(3) The adjustments must be performed in the circumstance of

25±5°C of temperature and 65±10% of relative humidity if
there is no specific designation.

(4) The input voltage of the receiver be must kept 110V, 60Hz

when adjusting.

(5) The receiver must be operational for about 15 minutes

prior to the adjustments.

1) After receiving 100% white pattern, the receiver must be

operated prior to adjustment. (Or 8. White Pattern
condition in EZ - Adjust)

2) Enter into White Pattern 

- Press POWER ON Key on the Service Remote

Control (S R/C)

- Enter the Ez - Adjust by pressing ADJ Key on the

Service Remote Control (S R/C).

- Select 7. White Pattern using the CH +/- Key and

press the Enter(Y) Key. 
Display the 100% Full White Pattern. 

[ Set is activated HEAT-RUN without signal generator in

this mode.

(1) Remote controller for adjustment  
(2) AV Pattern Generator: 802F Pattern Generator, Master

(MSPG-925FS), etc 
(Which has NTSC-J Composite Video format output with
standard (1.0 Vpp)  See Fig. 1)   

(3) It is very import to use correct adjustment pattern like

Fig.1.  

(1) Input the NTSC-J Composite Video (Fig.1.) into video

input.  
=> MSPG-925FS Model No: 207 / Pattern No: 65 / NTSC-J 

(2) Set the EZ Picture to Daylight mode in Video menu. 
(3) Press INSTART key on R/C for adjustment. 
(4) Press the 

G

(Vol. +) key operate to set, then it becomes

automatically. 

(5) Auto-RGB OK means completed adjustment. 

* When adjust main picture, sub picture is included. 

If you turn on a still screen more than 20 minutes (Especially
Digital pattern(13 CH), Cross Hatch Pattern), an afterimage
may occur in the black level part of the screen.

<Fig. 1>  Auto AV (CVBS) Color Balance Test Pattern 

Default Value on OSD