LG 42PG20R-TA (CHASSIS:PP81A) Service Manual ▷ View online
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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.
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.
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.
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.
with the specified.
When replacing a high wattage resistor (Oxide Metal Film Resistor,
over 1W), keep the resistor 10mm away from PCB.
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.
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.
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.
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
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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.
V
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)
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.
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
2) Demanded other specification
Safety : CE, IEC specification
EMC
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
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Market
Broadcasting system
Available Channel
Receiving system
SCART Input(2EA)
Video Input (1EA)
S-Video Input (1EA)
Component Input (1EA)
RGB Input(1EA)
HDMIInput(2EA)
Audio Input (5EA)
RS-232C(1EA)
USB Input(1EA)
1
2
3
4
5
6
7
8
9
10
11
12
13
No
Item
Specification
Remark
Non EU
PAL/ SECAM/ BG/I /DK, NTSC-M
BAND
PAL
VHF/UHF
E2~C69
CATV
S21~S47
Upper Heterodyne
PAL/SECAM/NTSC
PAL/SECAM/NTSC
PAL/SECAM/NTSC
Y/Cb/Cr, Y/Pb/Pr
RGB-PC, S/W Upgrade
HDMI-DTV, Only PCM Mode
AV (2EA), SIDE AV(1EA)
Remote control
Divx, MP3, JPEG
Rear 1EA, Side 1EA
Rear 1EA
Side AV : S-Video Priority
Rear HDMI(2)
L/R Input(PC 1EA, SCART 2EA,
SIDE AV 1EA, Component 1EA)
V
Model Specification
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ADJUSTMENT INSTRUCTION
1. Application Range
This spec. sheet is applied to all of the PP81A Chassis.
2. Specification
(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 instrument.
transformer will help protect test instrument.
(2) Adjustment must be done in the correct order.
(3) The adjustment must be performed in the circumstance of
(3) The adjustment must be performed in the circumstance of
25±5
c
C of temperature and 65±10% of relative humidity if
there is no specific designation.
(4) The input voltage of the receiver must keep 100~240V,
50/60Hz.
(5) Before adjustment, execute Heat-Run for 30 minutes at RF
no signal.
3. ADC calibration
3-1. PC input ADC
(1) Auto RGB Gain/Offset Adjustment
1) Convert to PC in Input-source
2) Signal equipment displays
2) Signal equipment displays
Output Voltage : 700 mVp-p
Impress Resolution XGA (1024 x 768 @ 60Hz)
Model : 60 in Pattern Generator
Impress Resolution XGA (1024 x 768 @ 60Hz)
Model : 60 in Pattern Generator
(1024x768@60Hz Black and White Pattern)
Pattern : 54 in Pattern Generator (MSPG-925 SERISE)
[1/2 Black & White Pattern (Refer below picture)].
[1/2 Black & White Pattern (Refer below picture)].
3) Adjust by commanding AUTO_COLOR_ADJUST(0xF1)
0x00 0x02 instruction.
(2) Confirmation
1) We confirm whether “0xF1 (offset), 0xF2 (gain)” address of
EEPROM “0xBC” is “0xAA” or not.
2) If “0xF1”, “0xF2” address of EEPROM “0xBC” isn’t “0xAA”,
we adjust once more
3) We can confirm the ADC values from “0x00~0x05”
addresses in a page “0xBC”
[ Manual ADC process using Service Remocon. After enter
Service Mode by pushing “ADJ” key, execute “ADC Adjust” by
pushing “
pushing “
G
” key at “Adjust-RGB”.
3-2. COMPONENT input ADC
(1) Component Gain/Offset Adjustment
1) Convert to Component in Input-source
2) Signal equipment displays
2) Signal equipment displays
Impress Resolution 720P
MODEL : 217 in Pattern Generator
MODEL : 217 in Pattern Generator
(720P/60Hz 100% Color Bar Mode)
PATTERN : 65 in Pattern Generator( MSPG-925 SERISE)
3) Adjust by commanding AUTO_COLOR_ADJUST(0xF1)
0x00 0x02 instruction
(2) Confirmation
1) We confirm whether “0xF3 (offset), 0xF4 (gain)” address of
EEPROM “0xBC” is “0xAA” or not.
2) If “0xF3”, “0xF4” address of EEPROM “0xBC” isn’t “0xAA”,
we adjust once more.
3) We can confirm the ADC values from “0x06~0x0B”
addresses in a page “0xBC
<Fig. 1>
Adjustment pattern (COMPONENT)
MSPG925FA
Component
RGB
ADC
Model : 60
(1024x768@60Hz)
Model : 216
(720P@60Hz)