background image
FILE NO. 050-200423
SERVICE MANUAL
44NHM84
PRINTED IN JAPAN, Dec., 2004


background image
- 2 -
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 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 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 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 1M and 5.2M.
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


background image
- 57 -
TABLE OF CONTENTS
SPECIFICATIONS ...................................................................................................... 4
DESCRIPTION OF CONTROLS ................................................................................ 5
ADJUSTMENT INSTRUCTION ................................................................................ 12
PRINTED CIRCUIT BOARDS .................................................................................. 18
BLOCK DIAGRAM ................................................................................................... 29
EXPOLODED VIEW ................................................................................................ 30
EXPOLODED VIEW PARTS LIST ......................................................................... 31
SCHEMATIC DIAGRAM .......................................................................................... 32
ELECTRICAL REPLACEMENT PARTS LIST .......................................................... 48
- 3 -


background image
- 4 -
Product Specifications
Model
44NHM84
Horizontal Size (Inches)
39.92
Height (Inches)
29.19
Depth (Inches)
14.29
Weight (lbs.)
59.5
Power Requirement
AC 120V, 60Hz
Television System
NTSC, External STB is required for the reception of Satellite broadcasting or Digital Cable
broadcasting
Television Channels
VHF: 2 - 13
UHF: 14 - 69
CATV: 1 - 125
Power Consumption (W)
230W
Antenna
75 ohm External Terminal for VHF/UHF
Audio Output (W)
12W x 2
External Input/Output Ports
A/V input (3 set)
Monitor out (1 set)
S-Video input (2)
COLORSTREAM HD input (2 set)
RGB input (1)
DVI input (1)
RGB/DVI audio input (1 set)
Variable audio output (1 set)
Audio center mode input (1)
Upgrade port (1)
RF input (1)
· This model complies with the specifications listed below.
· Designs and specifications are subject to change without notice.
· This model may not be compatible with features and/or specifications that may be
added in the future.
SPECIFICATIONS


background image
- 5 -
Function Status Indicators
Lamp indicator, operation indicator, and temperature indicator located below the front panel
controls, reveal the operating status of the DLP projection TV.
Operation Indicator
Lamp Indicator
Temperature Indicator
Off
Power cord is not connected.
Red
Power Cord is connected, TV is in standby mode.
Green
TV turns on.
Orange (flashing)
Preparing operation in standby mode.
Green (flashing)
The lamp cover is not closed.
Orange
The projection TV is overheating. Check the blocked vents of
the projection TV .
Red
The projection TV shut down due to overheating.
Red (flashing)
The projection TV shut down due to the cooling fan trouble.
Contact an authorized service center.
Operation Indicator
Lamp Indicator
Temperature Indicator
DESCRIPTION OF CONTROLS