LG21FG3RG-T9 CTV – how to enter the service mode, adjustments and circuit diagram

To protect the picture tube and FBT, the average beam current an d peak beam current may not to high.  The beam current limit information and High Voltage(H.V) tracking information are derived from the H.V voltage winding of T401 (point A).
1. The contrast and brightness reduction of RGB is proportional to the voltage on the pin 48 of IC501.
2. As the beam current(slow),and H.V (fast) are changes, the voltage of point A is changed.
3. By the increase of beam current ,the point A voltage is decreased and this information is fed to pin 48 of IC501.
* Contrast reduction begins when V49 is below than 3.1V.
* By the more increasing of the beam current , the V48 decreased and eventually when this voltage is less than 1.8V the brightness reduction is started.

The H drive output is open collector and active low, [the H-out TR should conduct during the low period of output.]

2. Under normal operation condition the duty cycle of the output pulse is 50%.
3. To ensure a smooth start/stop behavior of the horizontal deflection and protect the H-out TR, there are 3 different condition of H-drive output.
During switch-on.
The horizontal output starts with the double frequency (31KHz) and with duty of 75%(off),25%(on).
After about 50mSec of switch-on.
The frequency is changed to normal value(15.625KHz) and duty cycle to 50%.
During switching-off.
Also the frequency is switched to the double value and R.G.B drive is set to Max. and after 100mSec R.G.B is set to Min. and 50mSec later the H drive is switch-off.
4. The H drive pulse from the MICOM (IC 501) is amplified by the horizontal drive circuit, to get sufficient base drive current for the high voltage switching TR (Q401)

How to enter the service mode

Press the OK buttons on both TV set and Remote Controller at the same time to get into SVC mode.

CDL Data Adjustment (LINE SVC-0)
1) Press the SVC button to get into the SVC-0 Mode.
2) Press the Channel UP/DOWN button to select CDLl2.
3) Press the Volume UP/DOWN button until the CDL data is the same as the Table below.

4) Press the OK button to memorize the data.

OPTION Data Adjustment (OPTION-l,OPTION-2)
1) Press OK buttons on both TV set and Remote Controller at the same time to get into SVC mode.
2) Press the Yellow button several times to find OPTION data.
3) Input the correspond OPTION data referring to Table below with the numeric buttons.
4) Press the OK button to memorize the data.

AGC Adjustment (SERVICE 1)

1) Connect RF signal (70dBt0.2d8) and turn on the TV.

Standard adjustment Channel-EU 05 Ch. (frf= 175.25MHz)

2) Press the OK buttons on TV set and Remote Controller at the same time to get into SVC-0 mode.

3) In SVC-0 option, AGCTO is meant for AGC.

4) Press the Volume UP/DOWN button until the AGC Voltage is the same as the Table below.

5) Press the OK button to memorize the data.

Circuit diagram [SMPS and deflection]

Micom-Chroma schematic

White Balance Adjustment.(LINE SVC-0)

NOTE : This adjustment should be performed after screen voltage adjustment.
1) Tune the TV set to receive an 100% white pattern.
2) Press OK buttons on TV set and remote controller at the same time to get into SVC mode.
3) Use the CH CH Key to chose adjustment item.
4) Use the VOL VOL Key to change item data.
5) Adjustment.
a) Make the picture luminance 4.5 changing the " CONTRAST" and "BRIGHTNESS".
b) Adjust X data of low light with BLO-R and Y data with BLO-B.
c) Adjust X dada of High light RG and Y data with BG.
d) Repeat steps b & c until both low & high light hare same as shown below.

Screen voltage Adjustment

1) Connect the probe of oscilloscope to the RK (Red Cathode) of CPT Board.
2) Set the oscilloscope to 50V/div and 20Us/div and after putting GND line upon the lowest grid line of the scope by pressing GND button, enter into DC mode.
3) Tune the TV set to receive a PAL-BG O5GH.
4) Adjust Screen Volume of FBT so that the (DC 150).

TDA7297
15+15w dual bridge amplifier
features
Wide supply voltage range (6.5v-18v)
Minimum external components
Internally fixed gain
Stand-by & mute functions
Thermal overload protection
Short circuit protection

Hisense MSD308PX LCD Television – how to enter service mode – how to update the software - 32 inches LED backlight panel

To enter the Factory OSD Menu
a. With factory RC (remote control)
1. Press “M” button and enter factory mode.(Note1)
2. Press “Menu” button and enter factory OSD menu.
3. Press “CH+”/“CH-” button select the function menu, press “VOL+”/“VOL-” enter the selected function menu. Press “VOL+”/“VOL-” button adjust values in the menu.
4. Press “M” button exit factory mode in the factory OSD menu.
When TV outgoing factory, user cannot enter factory OSD menu with Factory Remote
Note:
1. In the “Factory Menu”, item “Function”>”TOFAC” ,you can select “M” or “U”, default is “U”.
- M-Means you can enter factory mode with factory RC or user RC.
- U-Means you can enter factory mode only with user’s RC.
2. Mode “M” is only used for factory production.

With user’s Remote control
Power on the TV.
1. Press “Menu” button and call up User OSD Menu.
2. Select “ Sound” > “Balance” item.
3. Press number key 1>9>6 >9 in sequence when “Balance” item is focused.
Note: If necessary, re-do number keys.
4. Factory OSD appears.
Note: Press the standby button then AC turn off and restart the TV, which can exit factory OSD menu.

Firmware update procedure

Upgrading with the ISP_TOOL
Hardware connecting
You can update the software through a special tool (as following)
Connect the Debug board to the TV use VGA interface or the RS232 (4 pin), the other USB port to the computer.

Install the ISP_TOOL4.5.0.4---- only for the first time update.
1 The software is upgraded by a burning tool- ISP_TOOL.exe
2 Find the folder where the ISP_TOOL4.5.0.4 lies in

There are three folders/files in this folder together.
DLPORTIO.dll and FTD2XX.DLL must be in the same folder
3 Double click the ISP_TOOL4.5.0.4 icon, and then a dialog window will show as below.

4 Click the” Config “button. And then a dialog window will show.

Draw on the front of “Use USB”
Port Type setting is USB
Base Addr setting is 0x38C
ISP Slave Address choose 0x92
Serial Debug Slave Address choose 0xB2，
5 Click the “Connect”button， if appear the following figure, It indicates that the ISP_TOOL has connected.(According to the tv set,”Device Type” maybe different.)

If appear the following figure， It indicates that the ISP_TOOL has not connected. Please click
the“DisCon”button and “Connect”button to connect..

6 Click the“Read ”button, Choose the correct update file.

7 After the update file has been chosen successfully.

Click the“Auto”button and choose parameters as following.

8 Click the “Run” button and wait update end.
If show any error message ， then do “Dis Con” >> “Connect”, and click the “Run” button again, till show the dialog window.

Upgrading with the USB
Software can update with USB device:
1. Copy the “*.BIN” file such as “MERGE.BIN” to the root directory of a USB disk.
2. Insert the USB disk into the USB slot of the TV SET.
3. Press “Menu” button and call up User OSD Menu, choose "Channel ">” Software Update(USB)” item. (Note 1)
4. Press “OK”, it will show a confirm message box, Press [◀] button to select “yes” in the confirm message box, to start automatic update.
5. Then it will update the software automatically, [don’t power off during the updating] process.
6. After the software is successfully upgraded, TV SET will restart automatically.
Note:
1. In some TV SET, ”Software Update(USB)” item maybe in “OPTION” menu.
2. After updating, you must confirm the software version in the “Factory Menu” and you'd better do a “Unprotected Clear" in the “Factory Menu”

Power assign:
The Power only has +12V_IN output ， other voltages are converted from +12V_IN.
a. 5Vstb is converted by N19 from +12V_IN， 5VAIN and 5V_USB are converted by N43 from 5Vstb.
b. 3.3Vstb and 3.3V_mcu as standby power supply for standby mode.
c. 3.3V_Normal supply power for N5 and Main IC N46 is converted by N3 from 5VAIN; 2.5V_Normal supply power for N46 is converted by N13 from 5VAIN; VDDC(1.28V) supply power for main IC(core voltage) is converted by N1 from 5VAIN;1.8VA supply power for N41(DDR),N45(DDR) is converted by N15 from 5VAIN.
e VCC_A supply power for N17(audio amplifier) is converted by N42 from +12V_IN; 5V_Tuner supply power for Tuner is converted by N16 from +12V; 5V_USB supply power for USB interface.
f VCC-Panel supply power for Panel is converted by N14 from +12V_IN

RF Signal

Digital intermediate frequency and simulation intermediate frequency are processed by Tuner (U42) from RF Signal. Transport Stream is demodulated directly by main IC from Digital intermediate frequency then enter PCMCIA card to decipher later return the main IC. The simulation intermediate signal that has passed amplification and surface acoustic wave filter to get intermediate frequency enters the main IC. After processed by main IC, next the video signal is processed by SCALER output LVDS signal.to panel . The audio signal is processed and the Audio amplified to the Speakers.

Control Process：

The Power only has 12V(+12V_IN) output ， other voltages are converted from 12V(+12V_IN). N43 and N42 can interrupt other voltages while standby, only reserve standby 5V(5Vstb) and standby 12V(+12V_IN). as following. When TV Power on , PWR-ON/OFF Signal is Low level, 5VAIN Power supply normally ; otherwise when TV standby , N43 is shut off , 5VAIN Power _supply is low.

+12V standby signal control as similar as 5VAIN

Power on, the Panel _Backlight and Brightness are control by the main board . the PIN 4 of XP2 is BL_ON/OFF, the high or low level control the BL_ON/OFF; the PIN 3 of XP2 is BL_ brightness Adjust, through control the level high or low to control the BL_ brightness.