LG 22LN4060 (CHASSIS:LM91P) Service Manual ▷ View online
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SERVICING PRECAUTIONS
CAUTION: Before servicing receivers covered by this service
manual and its supplements and addenda, read and follow the
SAFETY PRECAUTIONS on page 3 of this publication.
NOTE: If unforeseen circumstances create conflict between the
following servicing precautions and any of the safety precautions
on page 3 of this publication, always follow the safety precau-
tions. Remember: Safety First.
General Servicing Precautions
1. Always unplug the receiver AC power cord from the AC power
source before;
a. Removing or reinstalling any component, circuit board
module or any other receiver assembly.
b. Disconnecting or reconnecting any receiver electrical plug
or other electrical connection.
c. Connecting a test substitute in parallel with an electrolytic
capacitor in the receiver.
CAUTION: A wrong part substitution or incorrect polarity
installation of electrolytic capacitors may result in an explo-
sion hazard.
2. Test high voltage only by measuring it with an appropriate
high voltage meter or other voltage measuring device (DVM,
FETVOM, etc) equipped with a suitable high voltage probe.
Do not test high voltage by "drawing an arc".
3. Do not spray chemicals on or near this receiver or any of its
assemblies.
4. Unless specified otherwise in this service manual, clean
electrical contacts only by applying the following mixture to the
contacts with a pipe cleaner, cotton-tipped stick or comparable
non-abrasive applicator; 10 % (by volume) Acetone and 90 %
(by volume) isopropyl alcohol (90 % - 99 % strength)
CAUTION: This is a flammable mixture.
Unless specified otherwise in this service manual, lubrication
of contacts in not required.
5. Do not defeat any plug/socket B+ voltage interlocks with which
receivers covered by this service manual might be equipped.
6. Do not apply AC power to this instrument and/or any of its
electrical assemblies unless all solid-state device heat sinks
are correctly installed.
7. Always connect the test receiver ground lead to the receiver
chassis ground before connecting the test receiver positive
lead.
Always remove the test receiver ground lead last.
8. Use with this receiver only the test fixtures specified in this
service manual.
CAUTION: Do not connect the test fixture ground strap to any
heat sink in this receiver.
Electrostatically Sensitive (ES) Devices
Some semiconductor (solid-state) devices can be damaged eas-
ily by static electricity. Such components commonly are called
Electrostatically Sensitive (ES) Devices. Examples of typical ES
devices are integrated circuits and some field-effect transistors
and semiconductor “chip” components. The following techniques
should be used to help reduce the incidence of component dam-
age caused by static by static electricity.
1. Immediately before handling any semiconductor component or
semiconductor-equipped assembly, drain off any electrostatic
charge on your body by touching a known earth ground. Alter-
natively, obtain and wear a commercially available discharg-
ing wrist strap device, which should be removed to prevent
potential shock reasons prior to applying power to the unit
under test.
2. After removing an electrical assembly equipped with ES
devices, place the assembly on a conductive surface such as
aluminum foil, to prevent electrostatic charge buildup or expo-
sure of the assembly.
3. Use only a grounded-tip soldering iron to solder or unsolder
ES devices.
4. Use only an anti-static type solder removal device. Some sol-
der removal devices not classified as “anti-static” can generate
electrical charges sufficient to damage ES devices.
5. Do not use freon-propelled chemicals. These can generate
electrical charges sufficient to damage ES devices.
6. Do not remove a replacement ES device from its protective
package until immediately before you are ready to install it.
(Most replacement ES devices are packaged with leads elec-
trically shorted together by conductive foam, aluminum foil or
comparable conductive material).
7. Immediately before removing the protective material from the
leads of a replacement ES device, touch the protective mate-
rial to the chassis or circuit assembly into which the device will
be installed.
CAUTION: Be sure no power is applied to the chassis or cir-
cuit, and observe all other safety precautions.
8. Minimize bodily motions when handling unpackaged replace-
ment ES devices. (Otherwise harmless motion such as the
brushing together of your clothes fabric or the lifting of your
foot from a carpeted floor can generate static electricity suf-
ficient to damage an ES device.)
General Soldering Guidelines
1. Use a grounded-tip, low-wattage soldering iron and appropri-
ate tip size and shape that will maintain tip temperature within
the range or 500 °F to 600 °F.
2. Use an appropriate gauge of RMA resin-core solder composed
of 60 parts tin/40 parts lead.
3. Keep the soldering iron tip clean and well tinned.
4. Thoroughly clean the surfaces to be soldered. Use a mall wire-
bristle (0.5 inch, or 1.25 cm) brush with a metal handle.
Do not use freon-propelled spray-on cleaners.
5. Use the following unsoldering technique
a. Allow the soldering iron tip to reach normal temperature.
(500 °F to 600 °F)
b. Heat the component lead until the solder melts.
c. Quickly draw the melted solder with an anti-static, suction-
type solder removal device or with solder braid.
CAUTION: Work quickly to avoid overheating the circuit
board printed foil.
6. Use the following soldering technique.
a. Allow the soldering iron tip to reach a normal temperature
(500 °F to 600 °F)
b. First, hold the soldering iron tip and solder the strand
against the component lead until the solder melts.
c. Quickly move the soldering iron tip to the junction of the
component lead and the printed circuit foil, and hold it there
only until the solder flows onto and around both the compo-
nent lead and the foil.
CAUTION: Work quickly to avoid overheating the circuit
board printed foil.
d. Closely inspect the solder area and remove any excess or
splashed solder with a small wire-bristle brush.
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IC Remove/Replacement
Some chassis circuit boards have slotted holes (oblong) through
which the IC leads are inserted and then bent flat against the cir-
cuit foil. When holes are the slotted type, the following technique
should be used to remove and replace the IC. When working with
boards using the familiar round hole, use the standard technique
as outlined in paragraphs 5 and 6 above.
Removal
1. Desolder and straighten each IC lead in one operation by
gently prying up on the lead with the soldering iron tip as the
solder melts.
2. Draw away the melted solder with an anti-static suction-type
solder removal device (or with solder braid) before removing
the IC.
Replacement
1. Carefully insert the replacement IC in the circuit board.
2. Carefully bend each IC lead against the circuit foil pad and
solder it.
3. Clean the soldered areas with a small wire-bristle brush.
(It is not necessary to reapply acrylic coating to the areas).
"Small-Signal" Discrete Transistor
Removal/Replacement
1. Remove the defective transistor by clipping its leads as close
as possible to the component body.
2. Bend into a "U" shape the end of each of three leads remain-
ing on the circuit board.
3. Bend into a "U" shape the replacement transistor leads.
4. Connect the replacement transistor leads to the corresponding
leads extending from the circuit board and crimp the "U" with
long nose pliers to insure metal to metal contact then solder
each connection.
Power Output, Transistor Device
Removal/Replacement
1. Heat and remove all solder from around the transistor leads.
2. Remove the heat sink mounting screw (if so equipped).
3. Carefully remove the transistor from the heat sink of the circuit
board.
4. Insert new transistor in the circuit board.
5. Solder each transistor lead, and clip off excess lead.
6. Replace heat sink.
Diode Removal/Replacement
1. Remove defective diode by clipping its leads as close as pos-
sible to diode body.
2. Bend the two remaining leads perpendicular y to the circuit
board.
3. Observing diode polarity, wrap each lead of the new diode
around the corresponding lead on the circuit board.
4. Securely crimp each connection and solder it.
5. Inspect (on the circuit board copper side) the solder joints of
the two "original" leads. If they are not shiny, reheat them and
if necessary, apply additional solder.
Fuse and Conventional Resistor
Removal/Replacement
1. Clip each fuse or resistor lead at top of the circuit board hollow
stake.
2. Securely crimp the leads of replacement component around
notch at stake top.
3. Solder the connections.
CAUTION: Maintain original spacing between the replaced
component and adjacent components and the circuit board to
prevent excessive component temperatures.
Circuit Board Foil Repair
Excessive heat applied to the copper foil of any printed circuit
board will weaken the adhesive that bonds the foil to the circuit
board causing the foil to separate from or "lift-off" the board. The
following guidelines and procedures should be followed when-
ever this condition is encountered.
At IC Connections
To repair a defective copper pattern at IC connections use the
following procedure to install a jumper wire on the copper pattern
side of the circuit board. (Use this technique only on IC connec-
tions).
1. Carefully remove the damaged copper pattern with a sharp
knife. (Remove only as much copper as absolutely necessary).
2. carefully scratch away the solder resist and acrylic coating (if
used) from the end of the remaining copper pattern.
3. Bend a small "U" in one end of a small gauge jumper wire and
carefully crimp it around the IC pin. Solder the IC connection.
4. Route the jumper wire along the path of the out-away copper
pattern and let it overlap the previously scraped end of the
good copper pattern. Solder the overlapped area and clip off
any excess jumper wire.
At Other Connections
Use the following technique to repair the defective copper pattern
at connections other than IC Pins. This technique involves the
installation of a jumper wire on the component side of the circuit
board.
1. Remove the defective copper pattern with a sharp knife.
Remove at least 1/4 inch of copper, to ensure that a hazardous
condition will not exist if the jumper wire opens.
2. Trace along the copper pattern from both sides of the pattern
break and locate the nearest component that is directly con-
nected to the affected copper pattern.
3. Connect insulated 20-gauge jumper wire from the lead of the
nearest component on one side of the pattern break to the
lead of the nearest component on the other side.
Carefully crimp and solder the connections.
CAUTION: Be sure the insulated jumper wire is dressed so the
it does not touch components or sharp edges.
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SPECIFICATION
NOTE : Specifications and others are subject to change without notice for improvement.
1. Application range
This specification is applied to the LM91P chassis.
2. Requirement for Test
Each part is tested as below without special appointment.
(1) Temperature: 25 °C ± 5 °C(77 °F ± 9 °F), CST: 40 °C ± 5 °C
(2) Relative Humidity: 65 % ± 10 %
(3) Power Voltage
: Standard input voltage (AC 100-240 V~, 50/60 Hz)
* 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 : CE, IEC specification
- EMC : CE, IEC
4. Model General Specification
* HDMI 1.4 with Deep Color is only apply for FHD Model
No.
Item
Specification
Remarks
1.
Market
NON EU
2.
Broadcasting system
PAL/SECAM B/G/D/K
PAL-I
NTSC-M
3.
Channel Storage
BAND
PAL(BG,I)
NTSC(M)
China(DK)
VHF/UHF
01-C69
2~78
C1~C69
Cable
S1~S47
1~71
S1~S47
4.
Receiving system
Upper Heterodyne
5.
Video Input
PAL, SECAM, NTSC
Rear(1EA)
6.
USB Input
MP3, JPEG,Movie
Rear(1EA)
7.
AV Audio Output
RF/AV
Rear(1EA)
8.
Audio Input (1EA)
AV
L/R Input(2EA)
9.
Service jack
3.5mm headphone jack
Rear(1EA)
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ADJUSTMENT INSTRUCTION
1. Application Range
This specification sheet is applied to all of the LED TV with
LM91P chassis.
2. Designation
(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.
(2) Adjustment must be done in the correct order.
(3) The adjustment must be performed in the circumstance of
25 °C ± 5 °C of temperature and 65 % ± 10 % of relative
humidity if there is no specific designation.
(4) The input voltage of the receiver must keep 100-220 V,
50/60Hz.
(5) The receiver must be operated for over 5 minutes prior to
the adjustment when module is in the circumstance of
above 15 °C.
► In case of keeping module is in the circumstance of 0
°C, it should be placed in the circumstance of above 15
°C for 2 hours.
► In case of keeping module is in the circumstance of
below -20 °C, it should be placed in the circumstance of
above 15 °C for 3 hours.
* Caution
When a still image is displayed for 20 minutes or longer
(especially where W/B scale is strong. Digital pattern 13ch
and/or Cross hatch pattern 09ch), there can some
afterimage in the black level area.
3. White Balance Adjustment
3.1. Overview
3.1.1. W/B adj. Objective & How-it-works
(1) Objective: To reduce each Panel’s W/B deviation
(2) How-it-works: When R/G/B gain in the OSD is at 192, it
means the panel is at its Full Dynamic Range. In order to
prevent saturation of Full Dynamic range and data, one of
R/G/B is fixed at 192, and the other two is lowered to find
the desired value.
(3) Adj. condition: normal temperature
1) Surrounding Temperature: 25 °C ± 5 °C
2) Warm-up time: About 5 Min◦
3) Surrounding Humidity: 20% ~ 80%
4) Before White balance adjustment, Keep power on
status, don’t power off
3.1.2. Adj. condition and cautionary items
(1) Lighting condition in surrounding area surrounding lighting
should be lower 10 lux.
Try to isolate adj. area into dark surrounding.
(2) Probe location: Color Analyzer(CA-210) probe should be
within 10 cm and perpendicular of the module surface.
(80°~ 100°)
(3) Aging time
1) After Aging Start, Keep the Power ON status during 5
Minutes.
2) In case of LCD, Back-light on should be checked using
no signal or Full-white pattern.
3.2. Equipment
(1) Color Analyzer: CA-210 (NCG: CH 9 / WCG: CH12 / LED:
CH14)
(2) Adj. Computer(During auto adj., RS-232C protocol is needed)
(3) Adjust Remote control
(4) Video Signal Generator MSPG-925F 720p/204-Gray
(Model: 217, Pattern: 49)
* Color Analyzer Matrix should be calibrated using CS-1000.
3.3. Equipment connection
3.4. Adjustment Command (Protocol)
(1) RS-232C Command used during auto-adj.
(2) Adjustment Map
Color Analyzer
Computer
Pattern Generator
RS-232C
RS-232C
RS-232C
Probe
Signal Source
* If TV internal pattern is used, not needed
RS-232C COMMAND
Explantion
CMD
DATA
ID
wb
00
00
Begin White Balance adjustment
wb
00
ff
End White Balance adjustment
(internal pattern disappears )
Adj. item
Command
(lower caseASCII)
Data Range
(Hex.)
Default
(Decimal)
CMD1
CMD2
MIN
MAX
Cool
R Gain
j
g
00
C0
G Gain
j
h
00
C0
B Gain
j
i
00
C0
R Cut
G Cut
B Cut
G Cut
B Cut
Medium
R Gain
j
a
00
C0
G Gain
j
b
00
C0
B Gain
j
c
00
C0
R Cut
G Cut
B Cut
G Cut
B Cut
Warm
R Gain
j
d
00
C0
G Gain
j
e
00
C0
B Gain
j
f
00
C0
R Cut
G Cut
G Cut