ELECTRICAL ADJUSTMENTS
MONITOR SECTION
Execute the V-COM adjustment and flicker adjustment when you replace either the liquid crystal display (LCD2301), DISPLAY board, MAIN board or EEPROM (IC505) on the MAIN board.
Also, the setting value is saved in the EEPROM (IC505) on the MAIN board.
V-COM ADJUSTMENT
Procedure:
1. Connect an oscilloscope to TP2301 (VCOM) and TP2302 (GND) on the LCD board.
2. In the state of source off, press the [4] button on the remote commander.
3. Press the [5] button on the remote commander.
4. Press the [1] button on the remote commander for more than two seconds.
5. The test mode starts, and displayed on the monitor.
Execute the V-COM adjustment and flicker adjustment when you replace either the liquid crystal display (LCD2301), DISPLAY board, MAIN board or EEPROM (IC505) on the MAIN board.
Also, the setting value is saved in the EEPROM (IC505) on the MAIN board.
V-COM ADJUSTMENT
Procedure:
1. Connect an oscilloscope to TP2301 (VCOM) and TP2302 (GND) on the LCD board.
2. In the state of source off, press the [4] button on the remote commander.
3. Press the [5] button on the remote commander.
4. Press the [1] button on the remote commander for more than two seconds.
5. The test mode starts, and displayed on the monitor.
6. Press the [SRC] button on the
set or the remote commander to select the “AUX1”.
7. Touch the parts other than the touch panel button on the monitor.
7. Touch the parts other than the touch panel button on the monitor.
8. Adjust the [UP]/[DOWN] button
on the monitor so that the waveform level of oscilloscope becomes 5.8 ± 0.1 V .
9. Touch the [NEXT] button on the
monitor five times.
10. Touch the [SET] button on the
monitor to save the setting value.
11. Press the [OFF] button on the set or the remote commander to release the test mode.
FLICKER ADJUSTMENT
Procedure:
1. Input the NTSC white 30% raster signal from AUX3 VIDEO IN jack on the MOTOR board.
2. In the state of source off, press the [4] button on the remote commander.
3. Press the [5] button on the remote commander.
4. Press the [1] button on the remote commander for more than two seconds.
5. The test mode starts, and the screen is displayed on the monitor
11. Press the [OFF] button on the set or the remote commander to release the test mode.
FLICKER ADJUSTMENT
Procedure:
1. Input the NTSC white 30% raster signal from AUX3 VIDEO IN jack on the MOTOR board.
2. In the state of source off, press the [4] button on the remote commander.
3. Press the [5] button on the remote commander.
4. Press the [1] button on the remote commander for more than two seconds.
5. The test mode starts, and the screen is displayed on the monitor
6. Press the [SRC] button on the
set or the remote commander to select the “AUX3”.
7. Touch the parts other than the touch panel button on the monitor.
7. Touch the parts other than the touch panel button on the monitor.
8. Touch the [NEXT] button on the
monitor to display.
9. Adjust the [UP]/[DOWN] button on the monitor so that the flicker becomes minimum in the sight.
9. Adjust the [UP]/[DOWN] button on the monitor so that the flicker becomes minimum in the sight.
10. Touch the [NEXT] button on
the monitor four times.
11. Touch the [SET] button on the monitor to save the setting value
12. Press the [OFF] button on the set or the remote commander to release the test mode.
11. Touch the [SET] button on the monitor to save the setting value
12. Press the [OFF] button on the set or the remote commander to release the test mode.
TOUCH PANEL ADJUSTMENT
There are three kinds of adjustment values for the touch panel.
Default value : Value input from the beginning (Indefeasible value).
Factory adjustment value: Value adjusted by touch panel adjustment before having shipped at factory.
User adjustment value : Value that user adjusted by the Touch Panel Adjust.
When You Have Replaced the Touch Panel or Adjustment Value of the Touch Panel Shifts
Procedure:
1. In the state of source off, press the [4] button on the remote commander.
2. Press the [5] button on the remote commander.
3. Press the [1] button on the remote commander for more than two seconds.
4. The test mode starts.
There are three kinds of adjustment values for the touch panel.
Default value : Value input from the beginning (Indefeasible value).
Factory adjustment value: Value adjusted by touch panel adjustment before having shipped at factory.
User adjustment value : Value that user adjusted by the Touch Panel Adjust.
When You Have Replaced the Touch Panel or Adjustment Value of the Touch Panel Shifts
Procedure:
1. In the state of source off, press the [4] button on the remote commander.
2. Press the [5] button on the remote commander.
3. Press the [1] button on the remote commander for more than two seconds.
4. The test mode starts.
5. Press the [CSTM] button on the
set for more than two seconds.
6. Press the [CSTM] button on the set for more than two seconds to annul the factory adjustment value and the user adjustment value and the test mode start.
7. Press the [CSTM] button on the set for more than two seconds to display the touch panel adjustment screen.
8. Touch the center of cross on the monitor six times according to the screen (The factory adjustment value is set).
9. Press the [OFF] button on the set or the remote commander to release the test mode.
10. Confirm the touch panel operation by operating usually.
6. Press the [CSTM] button on the set for more than two seconds to annul the factory adjustment value and the user adjustment value and the test mode start.
7. Press the [CSTM] button on the set for more than two seconds to display the touch panel adjustment screen.
8. Touch the center of cross on the monitor six times according to the screen (The factory adjustment value is set).
9. Press the [OFF] button on the set or the remote commander to release the test mode.
10. Confirm the touch panel operation by operating usually.
TCON Board – What is TCON board – What is the Function of
TCON board – TCON board Voltages – LVDS Cable Configuration
FUNCTION OF TCON BOARD
The T-CON (TFT Controller) is responsible for;
1. Driving the TFT panel. This is usually accomplished by two LVDS type cables between the T-CON and the panel. The panel cell structure as into Vertical columns and Horizontal rows.
# Horizontal Resolution: On a panel with a resolution of 1920 X 1080 we must have 1920 X 3 columns, because a pixel is comprised on a Red, Green and Blue cell. So there will be 5760 individual cells in rows across the screen. To turn these cells on and off, the panel will use vertical address lines or electrodes driven by a small board located inside the panel. In this way we can turn the colors on and off accordingly to recreate the correct colors required to recreate the image.
# Vertical Resolution: On a panel with a resolution of 1920 X 1080 there will be 1080 horizontal rows of cells running across the panel. These rows are being driven by a small board inside the panel. By addressing a particular cell via the vertical columns and turning on a row of cells, only the cells being address by the vertical electrodes will be activated. The number of horizontal rows determine the panels Vertical resolution.
2. TFT: Each cell has is driven by a thin film transistor called (TFT) and a capacitor. When that cells is addressed (turned on) the capacitor will charge and will remain charged until the next refresh cycle. Generally speaking, when the cell has no power applied, it blocks the light from passing through, when it turns on, dependent upon how long it is on, allows more or less light to pass. In this way we can control the brightness level being output by that cell.
3.Panel Voltages: The T-CON is responsible for developing panel voltages. These voltage will vary dependent upon the type of panel utilized. Generally state there will be 4 voltages that are always being delivered to the panel, -5V, 3.3V, 16V and 26V. However, there may be more according to the type of panel being used.
The T-CON (TFT Controller) is responsible for;
1. Driving the TFT panel. This is usually accomplished by two LVDS type cables between the T-CON and the panel. The panel cell structure as into Vertical columns and Horizontal rows.
# Horizontal Resolution: On a panel with a resolution of 1920 X 1080 we must have 1920 X 3 columns, because a pixel is comprised on a Red, Green and Blue cell. So there will be 5760 individual cells in rows across the screen. To turn these cells on and off, the panel will use vertical address lines or electrodes driven by a small board located inside the panel. In this way we can turn the colors on and off accordingly to recreate the correct colors required to recreate the image.
# Vertical Resolution: On a panel with a resolution of 1920 X 1080 there will be 1080 horizontal rows of cells running across the panel. These rows are being driven by a small board inside the panel. By addressing a particular cell via the vertical columns and turning on a row of cells, only the cells being address by the vertical electrodes will be activated. The number of horizontal rows determine the panels Vertical resolution.
2. TFT: Each cell has is driven by a thin film transistor called (TFT) and a capacitor. When that cells is addressed (turned on) the capacitor will charge and will remain charged until the next refresh cycle. Generally speaking, when the cell has no power applied, it blocks the light from passing through, when it turns on, dependent upon how long it is on, allows more or less light to pass. In this way we can control the brightness level being output by that cell.
3.Panel Voltages: The T-CON is responsible for developing panel voltages. These voltage will vary dependent upon the type of panel utilized. Generally state there will be 4 voltages that are always being delivered to the panel, -5V, 3.3V, 16V and 26V. However, there may be more according to the type of panel being used.
Backlights: Since the Liquid crystal panel does not generate
any light of its own, there must be a light source behind the panel. This light
source is called the “Backlights” called B\L here after. The B\L can be either
florescent (EEFL or CCFL) or they can be LED.
Voltage Source for the
T-CON
The T-CON Voltage Source
will always be provided from the Main board. However, the Main board does not
actually generate the T-CON source voltage. All the Main board does is switch
on and off the voltage coming from the Power Supply. The Power Supply generates
a 12V supply that is sent to the Main board. When it is time to turn on the
T-CON, the Microprocessor will send out a command that turns on the T-CON 12V
and this voltage is routed through LVDS cable to the T-CON.
Voltages that the T-CON
Generates.
When the T-CON receives
the 12V from the Main board, it turns on DC-to-DC converters on the T-CON board
to generate several voltages. Some are used on the T-CON board itself (3.3V and
1.0V) and some are sent to the panel’s internal horizontal and vertical driving
board. Generally speaking, there are 4 primary voltages sent to the panel. They
are -5V, 3.3V, 16V and 26V. It is important to always check for these voltages
if you having problems with the T-CON board. But always remember there may be
more voltages generated and sent to the panel on different types of panels.
LVDS Cable (Low Voltage
Differential Signal)
The picture below shows
the LVDS cables routed from the Main board to the T-CON.
About LVDS Cable.
The LVDS (Low Voltage
Differential Signal) Cable in a LCD TV is responsible for two primary jobs.
1. VIDEO and TIMING SIGNALS: To deliver video signals that have been processed into a positive and a negative going pair of signals. These pair of signals are sent is groups which equal the resolution characteristics of the panel. As an example if the panel is a HD panel, the differential pair will be 10 lines carrying positive and negative video data. And there will be two line carrying positive and negative clock signals. If the panel is a full HD panel, it will have double the amount of lines.
The positive signals will be designated on the schematic with the suffix of (P or +) and the negative lines will be designated as (N or -). If you take one pair of video signals and look at them on a Oscilloscope, they will be and exact mirror of each other. By using a differential pair, the circuitry can isolate and remove the noise on the line by addition and it can extract the actual signal by subtraction which will double the signal level.
2. T-CON VOLTAGE: The T-CON board needs voltage to operate, the LVDS cable will deliver the T-CON’s operational voltage form Mother board.
If the LVDS cable is suspected of having a problem, most often it can be seen visually. Look for the cable being bent which cause the internal paths to be broken. The cable can be cut, or cracked or physically damaged in some way. The other problem that the LVDS cable can have is the continuity of contacts that are on the side that goes into the connector. This can only be seen by unlocking the cable connector and removing the cable. Then flipping the cable so the contacts points can be seen. See if they are separated from the cable. They could be curled up or even bent over and pressed onto another line causing a short. One other thing to look for is the cable being incorrectly inserted into the connector, (improperly seated).
1. VIDEO and TIMING SIGNALS: To deliver video signals that have been processed into a positive and a negative going pair of signals. These pair of signals are sent is groups which equal the resolution characteristics of the panel. As an example if the panel is a HD panel, the differential pair will be 10 lines carrying positive and negative video data. And there will be two line carrying positive and negative clock signals. If the panel is a full HD panel, it will have double the amount of lines.
The positive signals will be designated on the schematic with the suffix of (P or +) and the negative lines will be designated as (N or -). If you take one pair of video signals and look at them on a Oscilloscope, they will be and exact mirror of each other. By using a differential pair, the circuitry can isolate and remove the noise on the line by addition and it can extract the actual signal by subtraction which will double the signal level.
2. T-CON VOLTAGE: The T-CON board needs voltage to operate, the LVDS cable will deliver the T-CON’s operational voltage form Mother board.
If the LVDS cable is suspected of having a problem, most often it can be seen visually. Look for the cable being bent which cause the internal paths to be broken. The cable can be cut, or cracked or physically damaged in some way. The other problem that the LVDS cable can have is the continuity of contacts that are on the side that goes into the connector. This can only be seen by unlocking the cable connector and removing the cable. Then flipping the cable so the contacts points can be seen. See if they are separated from the cable. They could be curled up or even bent over and pressed onto another line causing a short. One other thing to look for is the cable being incorrectly inserted into the connector, (improperly seated).
When the LVDS cable is
causing a problem, the symptom can be many. Lines in the picture, portions
blocked out, every other line missing, noise pattern on the screen. Missing 12v
to the TCON board causing a black or no picture symptom, etc… It can even shut
the TV down if the 12V is shorted.
LVDS Cable Connectors
The LVDS cable can use
different types of connections to the Main board and to the T-CON.
Below shows some of the types of LVDS cable connections being used in LCD TVs.
Below shows some of the types of LVDS cable connections being used in LCD TVs.
LVDS Connector Contents
|
Pin
|
Label
|
Run
|
Check Diode
|
|
1
|
Gnd
|
Gnd
|
Gnd
|
|
2
|
3D_Sync_Out
|
0.03V
|
2.34V
|
|
3
|
*V_SYNC
|
3.33V
|
1V
|
|
4
|
SDA3_3.3V
|
3.34V
|
1.73V
|
|
5
|
SCL3_3.3V
|
3.34V
|
1.73V
|
|
6
|
FRC_RESET
|
3.32V
|
Open
|
|
7
|
n/c
|
n/c
|
n/c
|
|
8
|
3DTV
|
0V
|
Open
|
|
9
|
3D DIM
|
0V
|
Open
|
|
10
|
3D_DIM_2
|
0.05V
|
Open
|
|
11
|
n/c
|
n/c
|
n/c
|
|
12
|
RRXA0-
|
1.17V
|
1.67V
|
|
13
|
RRXA0+
|
1.19V
|
1.67V
|
|
14
|
RRXA1-
|
1.19V
|
1.67V
|
|
15
|
RRXA1+
|
1.17V
|
1.67V
|
|
16
|
RRXA2-
|
1.22V
|
1.67V
|
|
17
|
RRXA2+
|
1.14V
|
1.67V
|
|
18
|
Gnd
|
Gnd
|
Gnd
|
|
19
|
RRXACK-
|
1.16V
|
1.67V
|
|
20
|
RRXACK+
|
1.20V
|
1.67V
|
|
21
|
Gnd
|
Gnd
|
Gnd
|
|
22
|
RRXA3-
|
1.20V
|
1.67V
|
|
23
|
RRXA3+
|
1.14V
|
1.67V
|
|
Pin
|
Label
|
Run
|
Check Diode
|
|
24
|
RRXA4-
|
1.26V
|
1.67V
|
|
25
|
RRXA4+
|
1.08V
|
1.67V
|
|
26
|
Gnd
|
Gnd
|
Gnd
|
|
27
|
n/c
|
n/c
|
n/c
|
|
28
|
RRXB0-
|
1.19V
|
1.67V
|
|
29
|
RRXB0+
|
1.19V
|
1.67V
|
|
30
|
RRXB1-
|
1.19V
|
1.67V
|
|
31
|
RRXB1+
|
1.16V
|
1.67V
|
|
32
|
RRXB2-
|
1.2V
|
1.67V
|
|
33
|
RRXB2+
|
1.14V
|
1.67V
|
|
34
|
Gnd
|
Gnd
|
Gnd
|
|
35
|
RRXBCK-
|
1.16V
|
1.67V
|
|
36
|
RRXBCK+
|
1.2V
|
1.67V
|
|
37
|
Gnd
|
Gnd
|
Gnd
|
|
38
|
RRXB3-
|
1.22V
|
1.67V
|
|
39
|
RRXB3+
|
1.14V
|
1.67V
|
|
40
|
RRXB4-
|
1.26V
|
1.67V
|
|
41
|
RRXB4+
|
1.09V
|
1.67V
|
|
42-46
|
Gnd
|
Gnd
|
Gnd
|
|
47
|
n/c
|
n/c
|
n/c
|
|
48-51
|
PANEL_VCC
|
11.59V
|
Open
|
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