DOWNLOAD LG 19LD320 / 19LD320N (CHASSIS:LD91A) Service Manual ↓ Size: 3.94 MB | Pages: 77 in PDF or view online for FREE

Model
19LD320 19LD320N (CHASSIS:LD91A)
Pages
77
Size
3.94 MB
Type
PDF
Document
Service Manual
Brand
Device
TV / LCD
File
19ld320-19ld320n-chassis-ld91a.pdf
Date

LG 19LD320 / 19LD320N (CHASSIS:LD91A) Service Manual ▷ View online

- 5 -
IC Remove/Replacement
Some chassis circuit boards have slotted holes (oblong) through
which the IC leads are inserted and then bent flat against the
circuit 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 remaining
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
possible 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 whenever
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
connections).
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
connected 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.
- 6 -
SPECIFICATION
NOTE : Specifications and others are subject to change without notice for improvement.
1. Application range
This specification is applied to the LCD TV used LD91A
chassis.
2. Requirement for Test
Each part is tested as below without special appointment.
1) Temperature: 25 ºC ± 5 ºC(77 ºF ± 9 ºF), CST: 40 ºC ± 5 ºC
2) Relative Humidity :  65 % ± 10%
3) Power Voltage
: Standard input voltage (AC 100-240 V~, 50 / 60Hz)
* 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. Component Video Input (Y, C
B
/P
B
, C
R
/P
R
)
No.
Specification
Remark
Resolution
H-freq.(kHz)
V-freq.(Hz)
1.
720x480 15.73 
60.00 
SDTV,DVD 
480i
2.
720x480 15.63 
59.94 
SDTV,DVD 
480i
3.
720x480
31.47
59.94 480p
4.
720x480
31.50
60.00 480p
5.
720x576 
15.625 
50.00 
SDTV,DVD 625 Line
6.
720x576 31.25 
50.00
HDTV 
576p
7.
1280x720
45.00
50.00 HDTV 
720p
8.
1280x720
44.96
59.94 HDTV 
720p
9.
1280x720 45.00 
60.00 
HDTV 
720p
10.
1920x1080 31.25 
50.00 
HDTV 
1080i
11.
1920x1080
33.75
60.00 HDTV 
1080i
12.
1920x1080 33.72 
59.94 
HDTV 
1080i
13.
1920x1080 56.250 
50 
HDTV 
1080p
14.
1920x1080
67.5 60 
HDTV 
1080p
- 7 -
No
Specification
Proposed
Remark
Resolution
H-freq(kHz)
V-freq(Hz)
Pixel Clock(MHz)
1.
720*400 
31.468 
70.08
28.321 
For only DOS mode
2.
640*480 31.469 
59.94
25.17  VESA
Input 848*480 60 Hz, 852*480 60 Hz
-> 640*480 60 Hz Display
3.
800*600
37.879
60.31
40.00 VESA 
4.
1024*768 48.363 60.00
65.00 VESA(XGA) 
5.
1280*768 47.78 59.87
79.5 
WXGA 
 
6.
1360*768 47.72
59.8
84.75  WXGA
7.
1280*1024 63.595  60.0 
108.875
SXGA
FHD 
model 
8.
1920*1080 66.587
59.93
138.625  WUXGA
FHD 
model
5. RGB (PC)
6. HDMI Input (PC/DTV)
(1) DTV Mode
No
Resolution
H-freq(kHz)
V-freq.(Hz)
Pixel clock(MHz)
Proposed
Remark
1.
720*400 31.468 
70.08 
28.321 
HDCP
2.
640*480 31.469 
59.94 
25.17
VESA  HDCP
3. 800*600
37.879
60.31 
40.00 
VESA 
HDCP
4.
1024*768
48.363
60.00 65.00 
VESA(XGA)
HDCP
5.
1280*768 47.78
59.87
79.5
WXGA  HDCP
6.
1360*768 47.72 59.8 84.75
WXGA  HDCP
7.
1280*1024 63.595
60.0  108.875  SXGA
HDCP/FHD 
model
8.
1920*1080 67.5 
60.00
138.625  WUXGA
HDCP/FHD 
model
(2)  PC Mode
No
Resolution
H-freq(kHz)
V-freq.(Hz)
Pixel clock(MHz)
Proposed
Remark
1.
720*480 
31.469 /31.5 
59.94 /60
27.00/27.03
SDTV 480P
2.
720*576 31.25 
50
54 
SDTV 
576P
3.
1280*720 37.500 
50
74.25  HDTV 
720P
4.
1280*720 
44.96 /45 
59.94 /60
74.17/74.25 
HDTV 720P
5.
1920*1080 
33.72 /33.75 
59.94 /60
74.17/74.25 
HDTV 1080I
6.
1920*1080 28.125 50.00
74.25 
HDTV 
1080I
7.
1920*1080 
26.97 /27 
23.97 /24
74.17/74.25 
HDTV 1080P
8.
1920*1080
33.716 /33.75
29.976 /30.00
74.25
HDTV 1080P
9.
1920*1080 56.250 50
148.5
HDTV 
1080P
10.
1920*1080 
67.43 /67.5 
59.94 /60
148.35/148.50 
HDTV 1080P
- 8 -
ADJUSTMENT INSTRUCTION
1. Application Range
This specification sheet is applied to all of the LCD TV with
LD91A chassis.
2. Designation
1) The adjustment is according to the order which is
designated and which must be followed, according to the
plan which can be changed only on agreeing.
2) Power Adjustment: Free Voltage
3) Magnetic Field Condition: Nil.
4) Input signal Unit: Product Specification Standard
5) Reserve after operation: Above 5 Minutes (Heat Run)
Temperature : at 25 ºC ± 5 ºC 
Relative humidity : 65 % ± 10 %
Input voltage : 220 V, 60 Hz
6) Adjustment equipments: Color Analyzer (CA-210 or CA-
110), DDC Adjustment Jig equipment, SVC remote
controller
7) Push The “IN STOP” key - For memory initialization.
3. Main PCB check process
* APC - After Manual-Insult, executing APC
* Boot file Download
1) Execute ISP program “Mstar ISP Utility” and then click
“Config” tab.
2) Set as below, and then click “Auto Detect” and check “OK”
message
If “Error” is displayed, Check connection between
computer, jig, and set.
3) Click “Read” tab, and then load download file (XXXX.bin)
by clicking “Read”
4. Click “Connect” tab. If “Can’t” is displayed, check
connection between computer, jig, and set.
5. Click “Auto” tab and set as below
6. Click “Run”.
7. After downloading, check “OK” message.
* USB DOWNLOAD
1) Put the USB Stick to the USB socket 
2) Automatically detecting update file in USB Stick
- If your downloaded program version in USB Stick is Low,
it didn’t work. But your downloaded version is High, USB
data is automatically detecting
3) Show the message “Copying files from memory”
f i l ex x x .bi n
( 7 ) .........OK  
( 6) 
(5)
 
(1)
Please Check the Speed : To use speed between
from 200KHz to 400KHz
(2)
filexxx.bin
(3)
(4)
Case1 : Software version up
1. After downloading S/W by USB, TV set will reboot
automatically
2. Push “In-stop” key
3. Push “Power on” key
4. Function inspection
5. After function inspection, Push “I n-stop” key.
Case2 : Function check at the assembly line
1. When TV set is entering on the assembly line, Push
“In-stop” key at first.
2. Push “Power on” key for turning it on.
-> If you push “Power on” key, TV set will recover
channel information by itself.
3. After function inspection, Push “In-stop” key.
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