Samsung Le 27t51b Service Manual

							SERVICE
Manual
LCD TVFashion Feature
LCD-TV
Chassis Model
GTR23KE LE23T51B
GTR27KE LE27T51B
GTR32KE LE32T51B
- RF, DVI-D, PC(Analog), 2Scart, Component,   
Video, S-Video
- Brightness :  500cd/
- Contrast Ratio :  
23: 800:1,  27: 1000:1,  32: 800:1
- Respense time :  16ms
- Dynamic contrast
- PIP (on PC only)
 
						

							- TFT-LCD
(Thin film Transistor Liquid Crystal Display)
ADC(Analog to Digital Converter) 
This is a circuit that converts from analog signal to
digital signals.
- PLL(Phase Locked Loop)
During progressing ADC, Device makes clock syn-
chronizing HSYNC with Video clock  
- Inverter
Device that supply Power to LCD panel lamp. this
device gernerate about 1,500~2,000V.
- AC Adapter
Device that converts AC(90V~240V) to DC(+12V
or 14V)
- SMPS(Switching Mode Power Supply)
Switching Mode Power supply. This design tech-
nology is used to step up/down the input power by
switching on/off
- FRC(Frame Rate Controller)
Technology that change image frame quantity dis-
played on screen for one second.
Actually TFT-LCD panel require 60 pcs of frame
for one second.
so,this technology is needed to convert input
image to 60 pcs regardless input frame quantity.
- Image Scaler
Technology that convert various input resolution to
other resolution.(ex. 640* 480 to 1024*768)- Auto Configuration(Auto adjustment)
This is an algorithm to adjust monitor to optimum
condition by pushing one key.
- OSD(On Screen Display)
On screen display. customer can control the
screen easily with this.
- Image Lock
This means Fineness adjustment  in LCD
Monitor, the features are Fine and Coarse 
- FINE
Fine adjustment is used to adjust visibility by
control phase difference.
- COARSE
This is a adjustment by tuning with Video colck
and PLL clock. 
- DVI (Digital Visual Interface)
This provides a high speed digital connection for
visual data types that is display technology 
independent. this interface is primarily forcused at
providing a connection between a computer and
its display device.
- L.V.D.S.(Low Voltage Differential Signaling)
a kind of transmission method for Digital.It can be
used from Main PBA to Panel.
- DVI (Digital Visual Interface)
This provides a high speed digital connection for
visual data types that is display technology inde-
pendent. this interface is primarily forcused at pro-
viding a connection between a computer and its
display device.14 Reference Infomation
14-1
14 Reference Infomation
14-1 Technical Terms
 
						

							14 Reference Infomation
14-2
- T.M.D.S
(Transition minimized Differential Signaling)
a kind of transmission method for Digital. 
It can be used from Video card to Main PBA.
- DDC(Display data channel)
It is a communication method between Host
Computer and related equipment.
It can make it Plug and Play between  PC and
Monitor.
- EDID
Extended Display Identification Data PC can rec-
ognize the monitor information as Product data,
Product name,Display mode,Serial number and
Signal source,etc through DDC Line communicat-
ing with PC and Monitor. 
- Dot Pitch
The image on a monitor is composed of red, green
and blue dots. The closer the dots, the higher the
resolution. The distance between two dots of the
same color is called the Dot Pitch. Unit: mm
- Vertical Frequency
The screen must be redrawn several times per
second in order to create and display an image for
the user. The frequency of this repetition per sec-
ond is called Vertical Frequency or Refresh Rate.
Unit: Hz 
Example: If the same light repeats itself 60 times
per second, this is regarded as 60 Hz.  
- Horizontal Frequency
The time to scan one line connecting the right
edge to the left edge of the screen horizontally is
called Horizontal Cycle. The inverse number of the
Horizontal Cycle is called Horizontal Frequency.
Unit: kHz- Interlace and Non-Interlace Methods
Showing the horizontal lines of the screen from the
top to the bottom in order is called the Non-
Interlace method while showing odd lines and then
even lines in turn is called the Interlace method.
The Non-Interlace method is used for the majority
of monitors to ensure a clear image. The Interlace
method is the same as that used in TVs.
- Plug & Play 
This is a function that provides the best quality
screen for the user by allowing the computer and
the monitor to exchange information automatically.
This monitor follows the international standard
VESA DDC for the Plug & Play function.
- Resolution
The number of horizontal and vertical dots used to
compose the screen image is called resolution.
This number shows the accuracy of the display.
High resolution is good for performing multiple
tasks as more image information can be shown on
the screen. 
Example:  If the resolution is 1280 x 1024 , this
means the screen is composed of 1280 horizontal
dots (horizontal resolution) and 1024 vertical lines
(vertical resolution). 
- BTSC
Broadcast Television System Committee
The stereo broadcasting system that is used in
most of the countries that have adopted the NTSC
system, including the United States, Canada,
Chile, Venezuela and Taiwan. It also refers to the
organization that has been organized to promote
its development and management.
- EIAJ 
Electronic Industries Association of Japan.
- RF Cable 
A round signal cable generally used for TV antennas. 
 
						

							- Satellite Broadcasting 
Broadcasting service provided via satellite.
Enables high picture quality and clear sound
throughout the country regardless of the location of
the viewer. 
- Sound Balance 
Balances the levels of the sound coming from
each speaker in televisions with two speakers. 
- Cable TV 
Whereas the terrestrial broadcasting is delivered
via frequency signals through the air, cable broad-
casting is transmitted via a cable network. In order
to view cable TV, one must purchase a cable
receiver and hook it up to the cable network.
- CATV
CATV refers to the broadcasting service offered
at hotels, schools and other buildings through their
own broadcasting system, apart from VHF or UHF
broadcasting by terrestrial broadcasters. The
CATV programs may include movies, entertain-
ment and educational programs. (Different from
cable TV.)
CATV can be viewed only within the area in which
the CATV service is offered.
- S-Video 
Short for Super Video. S-Video allows up to 800
lines of horizontal resolution, enabling high-quality
video.
- VHF/UHF 
VHF indicates TV channels 2 to 13, and UHF indi-
cates channels 14 through 69.- Channel Fine Tuning
This feature allows the viewer to fine-tune the TV
channel to obtain the best viewing conditions. The
Samsung LCD TV has both automatic and manual
channel fine-tuning features to enable the viewer
to adjust their desired settings.
- External Device Input
External device input refers to video input from
such external video devices as VCRs, camcorders
and DVD players, separate from a TV broadcast. 14 Reference Infomation
14-3
 
						

							14 Reference Infomation
14-4
14-2-1 DVI-D
14-2 Pin Assignments
NC
DDC Input power (+5V)
IDENT-DVI
Output Signal (HDCP Control)
Rx0-
Rx0+
GND
NC
NC
GND
RxC+
RxC- 13
14
15
16
17
18
19
20
21
22
23
24 1
2
3
4
5
6
7
8
9
10
11
12Rx2-
Rx2+
GND
NC
NC
DDC - SCL
DDC - SDA
NC
Rx1-
Rx1+
GND
NC Sync
Type
Pin No.24P DVI-D
Figure 1.
 
						

							14 Reference Infomation
14-5
Both screen position and size will vary depending on the type of PC monitor and its resolution.
The resolutions in the table are recommended. (All resolutions between the supported limits are supported)
- The interlace mode is not supported.
- The set might operate abnormally if a non-standard video format is selected.
- DVI dose not support PC function.
PinSeparate
1
2
3
4
5GND
Y
C
GND
GND
RCA Green
RCA Blue
RCA Red
RCA White
RCA RedY
GND
Pb (Cb)
GND
Pr (Cr)
GND
Audio L
GND
Audio R
GND
14-2-3 S-Video
PinSeparate
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15Red
Green
Blue
GND
GND
GND Red
GND Green
GND Blue
DDC Input power(+5V)
IDENT PC
GND
DDC Data(SDA)
H SYNC
V SYNC
DDC Clock(SCL)
14-2-5 D-SUB
14-2-2 Component
RCA White
RCA RedCVBS
Audio L
GND
Audio R
GND
14-2-4 A/V
RCA Yellow
14-2-6 PC Display mode
Mode
IBM
VESAResolution
640 x 480
720 x 400
640 x 480
640 x 480
800 x 600
800 x 600
800 x 600
1024 x 768
1024 x 768
1024 x 768
1360 x 768Horizontal
Frequency (kHz)
31.469
31.469
37.861
37.500
37.879
48.077
46.875
48.364
56.476
60.023
47.712Vertical
Frequency (Hz)
59.940
70.087
72.809
75.000
60.317
72.188
75.000
60.000
70.069
75.029
60.015Pixel Clock
Frequency (MHz)
25.175
28.322
31.500
31.500
40.000
50.000
49.500
65.000
75.000
78.750
85.800Sync Polarity
(H/V)
- / -
- / +
- / -
- / -
+ /+
+ /+
+ /+
- / -
- / -
+ /+
+ /+
 
						

							14 Reference Infomation
14-6
14-2-7 Scart 1
14-2-8 Scart 2
Pin Signal
1 Audio output R
2 Audio input R
3 Audio output L
4 Audio common GND
5 Video GND (RGB blue)
6 Audio input L
7 RGB blue input
8 Switching voltage
9 Video GND (RGB green)
10 NC
11 RGB green input
Pin Signal
12 NC
13 Video GND (RGB red)
14 GND
15 RGB red input
16 Fast Blanking signal 
(RGB switching)
17 Video output GND
18 Video input GND
19 Video output (CVBS out)
20 Video input (CVBS in)
21 Common GND
Pin Signal
1 Audio output R
2 Audio input R
3 Audio output L
4 Audio common GND
5 Video GND (RGB blue)
6 Audio input L
7 RGB blue input
8 Switching voltage
9 Video GND (RGB green)
10 NC
11 RGB green input
Pin Signal
12 NC
13 Video GND (RGB red)
14 GND
15 RGB red input
16 NC
17 Video output GND
18 Video input GND
19 Video output (CVBS out)
20 Video input (CVBS in)
21 Common GND
 
						

							14 Reference Infomation
14-7
14-3 Timing Chart
This section of the service manual describes the timing that the computer industry recognizes as standard for computer-
generated video signals.
14-3-1 LCD Panel Mode1 mode
 
						

							14 Reference Infomation
14-8
14-3-2 Supported Modes (1)
 
						

							14 Reference Infomation
14-9
14-3-3 Supported Modes (2)