REPAIRING / SERVICING TV LG WITH GIP PANEL THE IMAGE CHANGES / SHAKES PERIODICALLY

The  Pictures on the panel screen are sometimes good, sometimes flawed …… .. alternating periodically.
Defects can have many kinds of symptoms: maybe shakes, maybe lines, maybe doubles etc.



This can happen to LG using the GIP (Gate In Panel) panel.

    Which is indicated by the presence of VGH_ODD and VGH_EVEN voltages from the Tcon that enter the panel (image above).
    If the voltage at both TP is measured, it will keep changing periodically ...
    Sometimes the positive voltage is VGH / sometimes the negative voltage is VGL.
    The voltages VGH_Even and VGH_Odd are always opposite. This means that if VGH_even is positive, then VGH_Odd will be negative.


The same symptoms can also be found on AUO panel models. Where there is also found a TP whose voltage is always changing positive and negative.

 AUO panel pictures sometimes good, sometimes double or blurry

 

Panel 32 made by AUO….
Unclear panel type …….
Picture problem changes periodically .... sometimes good sometimes double / blurred
Near the COF column there are test points HC1, HC2, LC1, LC2
................. can be solved ……. Because there are similar problems with LG using Vgh_O and Vgh_E

Check the voltage at the LC2 test point changing periodically ...
Sometimes the same as Vgh, sometimes negative with Vgl …….

     When the voltage is equal to Vgh the picture is fine.
     When the voltage is equal to Vgl image problem...


Check the voltage on the test point LC1 also changes periodically the same as above ... the difference is only when the image is good the voltage is the same as Vgl.

Check with an ohm meter ..... LC1, LC2 voltage supply from IC Level Shifter 17328.
Cut the connection from LC1, LC2 to the IC Level Shifter by removing the R jumper.
Then dial directly:

     LC2 fixed to Vgh voltage.
     LC1 fixed direct dial to Vgl. .

This is not a T.con malfunction, but a glass panel malfunction similar to the Samsung image shake / double panel damage.

The solutions to the above problems are:

The first step.

    Observe the picture …… .. while measuring the VGH_odd voltage (or it could be VGH_Even)
    Observe carefully the voltage when the image position is good, what is the VGH_odd voltage.
    For example, a good image when the VGH_Odd voltage is positive.


Second step.

    Cut the VGH_Odd and VGH_Even paths entering the panel from the source.
    This voltage comes from an IC called LEVEL SHIFTER.


Third step.

    After the line is cut.
    Because the picture is good when the position of the VGH_Odd voltage is positive.
    Then the jumper goes directly to VGH_Odd to VGH
    And the reverse is the VGH-Even to VGL jumper.


Note:

    If the image is good when VGH_Odd is negative.
    Then VGH_Odd is jumped to VGL


 
 
 

REPAIRING / SERVICING LCD LED TV KNOWLEDGE SERVICE GUIDE

Lcd / Led technology will be more difficult for beginners, because everyday they will be dealing with various brands and models. From the old school to the last product. From simple economical products, to sophisticated and intricate.

   

    Lcd / Led technology is developing very fast. From Lcd technology moved to Led technology, Multimedia technology. Even now there is a newer technology called OLED, but it is not yet popular because the price is still quite high.
    Some use single Psu, and some use Dual Psu
    Some use a separate Psu-Inverter-Motherboard board, and some use only one board.
    There are Microprocessors that are separate from the Video Processor, and some have been combined into a single chip.
    The use of IC Nand Flash and Emmc memory on the new models, while the old models still rely on IC Flash memory.
    The use of external RAM ic and some use internal RAM so the unity in the ic chip.


KINDS OF VOLTAGE REDUCING REGULATORS IN THE MOTHERBOARD

We start to understand the types of powersuply regulator ic found on the motherboard. The motherboard circuit requires a variety of voltages. For this purpose, the input voltage supply to the motherboard must be converted / converted to various voltages whose values ​​can be different, for example 5v, 3.3v, 2.5v, 1.8v and 1.2v.

Lowering regulators used in motherboards can be categorized into two types, namely:

    LDO
    Dc-Dc


LDO (Low Drops Out Regulator).
It is a regulator whose work is almost similar to the 7805, 7812 which we have often encountered on CRT TVs. There are various forms, some are similar to a 3 leg transistor, some are shaped like an 8 foot memory ic, and some are in the form of a small 5 foot ic.
LDOs generate less heat than regulators such as the 7805.
Generally, the maximum is only capable of providing a current of less than 1A.
In the use of "Input and Output voltage difference" LDO should not be too large. For example, it should not be used to reduce the voltage from 12v to 3.3v. It should only be used from 5v to 3.3v for example. Because the greater the difference between the input-output voltages, the hotter the regulator. LDO circuits are quite simple because they do not require many external components.

 

 

 

 

 

 

LDO output.
There are 2 types of LDO output:

     FIXED or fixed output voltage. For example voltage2: 5v, 3.3v, 2.5v. 1.8v

     The output voltage can be verified by changing the value of the external resistor component.

LDO with on-off control

     There are LDOs that are not controlled on-off, for example, such as 7805, 78012
     There are also types of LDOs that have an on-off control pin, for example, the 78R05, 78R12.

 

 

 

 DC-DC Step-Down Converter or other name Buck Converter.
It is a regulator that works similar to how a switching regulator works.
The shape is similar to an 8-foot memory ic, some are smaller and have 6 feet.
The characteristics of dc-dc ic is the presence of an inductor (coil) that is nearby.
DC-dc generates very little or no heat, so it doesn't require cooling. The maximum current is generally capable of up to 3A.
The large difference between the Input and Output voltages does not cause problems (no heat), for example from 19v to 1.2v. Of course, things like this cannot be done using LDOs.
Compared to LDO, dc-dc has a slightly more complex circuit, requiring more external components.

 

 

 

MOTHERBOARD IS OFF TOTAL or DOES NOT WANT TO STBY
What to do if you find a completely dead motherboard.
Here we only limit discussing what needs to be checked so that the Microcontroller is ready for Power-on.
Important points that must be examined in full is to understand the order of work of the Microprocessor from the time it is plugged in until it is ready to turn on:
 The Microprocessor receives a Stby 3.3v and 1.2v Vcore supply voltage
 The Microprocessor receives the HW RESET voltage (Hard Ware reset)
 The Microprocessor generates system clock pulses with the help of X.tal oscillator.
 The Microprocessor communicates with the SPI Flash memory via the sda / scl line.
 The Microprocessor is ready to get commands from the control input system.
* There is one more thing to remember, because this one does not use all motherboards, namely the Microcomputer needs to get AC_det voltage input.

 UNSWITCHED and SWITCHED REGULATORS

Many beginners make mistakes in doing analysis ………
Found one or more of the voltage regulators on the motherboard that hasn't appeared yet ………
Then focus the tinkering on that part …… .. In actual fact that part doesn't matter …….
How could this happen ???

LDO and Dc-dc regulators can be divided into two, namely:

    UNSWITCH (not switched), which is the Stby voltage which is always there when the power plug is installed during standby or on. This is the voltage required for the microcon section to work. The voltage for standby generally requires 2 types, namely 3.3v and 1.2v
    SWITCHED (can be switched), the output voltage can be switched "on-off". This voltage only appears when the aircraft is power-on. Here the microcontroller will issue a voltage command "POWER_ON" so that the regulator will issue an output voltage.

 

Finding the total dead problem, then you must first focus on the UNSWITCH voltages.

TRACKING STBY VOLTAGE
Generally, 2 kinds of unswitched voltages are needed for standby, namely 3.3v and Vcore 1.2v

    3.3v unswitched to supply IC Chips / Microcons, Memory, remote sensors. Can use the LDO or Dc-dc types. Its presence is easiest to check on the Vcc-ic Flash memory pin or on the Vcc remote sensor leg
    Vcore 1.2v always uses dc-dc. Because here it takes a large current up to 3A. Without the schematic it is difficult to determine which Dc-dc is for V.core. But you can try to find it by trying to measure all the Dc-dc that is on standby. If you find 1.2v, that's the V.core scene. If you still don't find the possibility of a short Dc-dc output, just try to measure all the existing dc-dc outputs with an ohm meter, and you'll find a short one. It could be caused by a short filter output capacitor, short ic chip, or damaged dc-dc

     STBY VOLTAGE

Generally, the Microprocessor gets 2 kinds of supply voltage UN-SWITCH 3.3v and Vcore 1.2v

    3.3v - Sometimes you get it directly from Psu, some use Dc-dc stepdown, some use LDO. The voltage can be checked on the Vcc ic Flash pin-8 or at the Vcc Remote sensor.
    1.2v - Vcore is obtained always using Dc-dc stepdown. Because here a large amperage (3A) is needed.

Without a schematic it is difficult to determine which Dc-dc for V.core.
But you can try to find it by trying to measure all the Dc-dc that is on standby.
If you find 1.2v, that's the V. core voltage
If you still can't find it, chances are Dc-dc is short. Just check all available Dc-dc outputs with an ohm meter. If you find someone who is short, that's most likely Dc-dc V.core. It could be because the components in the Dc-dc output line are short, such as the filter output capacitor, ic chip, or the Dc-dc ic itself is damaged.
Vcore drops are sometimes caused by a damaged ic chip.

HW RESET.

A computer hardware reset or hard reset is a hardware operation that re-initializes the core hardware components of the system, thus ending all current software operations in the system. This is usually, but not always, followed by booting the system into firmware which re-initializes the rest of the system, and restarts the operating system. A hardware reset is an important part of the startup process for the microcon to be ready for "power-on"

Reset can also be triggered by direct intervention via the "reset button" located on the motherboard

Unlike CRT TVs, Lcd / Led generally get an active reset voltage "High". This means that as soon as the power plug is installed the Reset pin will get a "high" voltage for a moment it continues to disappear.

Reset Voltage can be checked in the following manner:

    Pin-Reset can be found through the ic chip datasheet used.
    Install the avo first, to measure the pin-reset voltage.
    Recently the power plug was installed.
    Normal voltage will appear for a moment. It can be seen with the avo needle slightly wobbling. Henceforth after the TV is on, the normal pin-reset voltage is zero.

Reset circuit can only be known by looking at the schematic of the model concerned. Some use ic and some use transitor only.

.

 X.TAL OSCILLATOR

Oscillating action provides the system clock pulses.
The most accurate way to check the presence of clock pulses is with the help of an oscilloscope. But if there is no oscilloscope, it can also, even though it is not 100% correct, check for the presence of voltages on the Xtal leg. Generally around 1.25 - 1.75v


DATA COMMUNICATION WITH SPI FLASH
 
Data communication microcons with IC SPI Flash through the SDA / SCL line to be able to Read & Write data. These two lines usually have a voltage of around 3v and must be the same.

Every time after the power plug is installed, the Microprocessor will read the SPI Flash memory data and upload the data into the RAM memory system which is internally inside the Microprocessor itself. If the Microprocessor fails to communicate with IC SPI Flash or FW data ic Flash error, then the Microprocessor will fail Stby.

Conversely, when the TV is turned off, the Microprocessor will write back data into the SPI Flash ic. Where here the data may have been changed, for example image mode data, voice mode data, or maybe sermod data etc.

Sometimes the communication system from Microprocessor to is SPI Flash can also be disrupted due to poor connection. Or sometimes if you use something like R the jumper is delayed.

Data error problems are most often found on LCD / Led compared to CRT TV, which causes the Microprocessor to fail. Maybe this is because the FW data is very large compared to CRT TV data. So that there is a greater possibility of errors when Read or Re-write.

 

INPUT SYSTEM

Although it rarely happens, it is possible that the Mikrokon will not function only because the command from the INPUT system is problematic. There are 2 sources of input command, namely

    IR sensor.
    Key-in.

The most frequently found damage in this section is the presence of a leaky or short C smd. Sometimes we also find dirty pcb problems on the lines between the pcb control and the ic chip.


AC_DET

Not all models are equipped with an AC-det circuit. The AC_det circuit is in the primary Psu section, monitoring the AC voltage input voltage is healthy or not. The AC_det voltage is inputted from the primary Psu via the Photocoupler to the secondary Psu, …… .. and then to the Mikrokon. Normal if AC-det is healthy there is a voltage of about 3-4v to the Mikrokon.
If the Microprocessor has no AC-det, the Microprocessor will fail to standby.

You could say AC_det is similar to an AC-input voltage protective circuit. If the AC-input voltage drops below a certain level, the Microprocessor will shut off.

Sometimes the technician, if he is bothered to track down looking for damage to this section ... ... just keep looking for an easy way .... that is to provide a fixed voltage on pin-AC_det.

 

 Microprocessor  failure can also be due to damage to the IC chip or problems with the soldering of the chip feet that have lost contact.
Chips with signs when touched is hot. Means it can't be helped unless you have to replace the chip.

 

 we examined  how the steps of the Microprocessor  section work so that they are ready to be "Power on-off control". These are only a fraction of the motherboard functions, so we have a lot to cover.

What are the next stages to understand & learn.
So we invite again to understand the stages on CRT television, which are roughly as follows:
 The Microprocessor issues a "power-on" command to the circuit switch on or regulator 8v and 5v.
 8v and 5v voltages are present.
 8v to supply voltage Horizontal start.
 And 5v for audio / video circuits for chroma ic processors, tuners etc.
 Got "8v" the Horizontal section will start working, continue until the Flyback gushes.
 The vertical part of the flyback will get Vcc supply, and the CRT will get a Heater, Screen, Focus, 180v supply voltage.
 The vertical part begins to work….
 And the CRT screen is ready to turn on, but while still on MUTE.
 Then Chroma outputs an RGB image signal ... ... and the screen appears.

 

 

 Likewise on Lcd / Led.
Microprocessor stages have been passed and ready for Stby.
After pressing the power button,
Then the Microprocessor will output the "power-on" control which will function to turn on several regulators that are SWITCHED to provide various voltage supplies in parts, such as SCALLER (Video processor), Tuner, ic RAM (DDR2), ic Eeprom etc.

.

The picture above is an example of a voltage block that works on a motherboard using TSUMV59.

     The red line is the UN-Switch 3.3v and 1.2v voltages for the Microprocessor section.
     Lcd.Led remote sensors made in China generally get 5v voltage. Meanwhile, those made in Korea and Japan generally get 3.3v.
     The blue line is the supply which is switched on-off. Output voltage 3.3v for Audi / Video processor, Eeprom memory, Tuner and 1.8v voltage for RAM memory (internal).
     Audio ICs can generally be Vcc 12v directly UN-Switch, but for 3.3v supplied from a controlled on-off.


On old LCD / LEDs or large screen TVs which still use a separate Psu module from the motherboard, generally they still use 2 kinds of powersuply circuits.

      Small powersuply to provide motherboard Stby voltage
      Main Power Supply (large) to supply voltages to other motherboards.

Here the "power-on" command from the motherboard is required to turn on:

     Main power supply.
     PFC circuit.

     Many beginners don't understand.
Check the main powersuply has not issued a voltage. Continue to search for the cause.
In fact, Powersupky has no problem. The motherboard is the problem, because it hasn't issued a power-on command to Powersuply Main or it's still Stby.


DAMAGE TO SWITCH ON-OFF VOLTAGE REGULATOR.

If any of the voltages does not come out or drops, it can cause various symptoms of damage such as:

     The indicator is green, but the picture and sound are not there
     Restart repeatedly.
     Just jammed up the logo.
     Live or die alone.
     Or maybe dead stby protection

Symptoms like this can all vary in different modes. depending on the design of each manufacturer / brand.

•  The Stby light can go out or turn green when it is turned on.
  All motherboard voltages that are switched on-off are present.
  Then the next process, the Microprocessor  will output the controls as follows:
   Inverter_on which will turn on the BL (backlight) lamp
   Panel_on which will control the "Vcc Tcon Switch panel" to output a voltage of Vcc 5v (if the panel is small) or 12v (if the panel is large).
   PWM_dim which will control the brightness of the BL lamp.
   Simultaneously with the active PWM_dim, the LVDS image data starts to actively output the image signal to Tcon ..
   Some models will immediately appear images. But there are also those that will display the LOGO first, then a few seconds later the image appears.

 

 

All settings for the working sequence of the Microprocessor  as described from , until the logo and TV images come out are all arranged using FIRMWARE embedded in flash memory ic. Therefore, if a problem occurs in the working order or gets stuck in the middle of the road, it could be due to damage to DATA FIRMWARE or due to damage to the Flash memory ic.

Process like the above is a standard process.

In certain models there may be additions or differences, for example
SONY

If the LVDS to Tcon cable is not installed or the panel installed is not Sony originals. So after Panel_on, the process will stop. And the plane is dead in protection with a blinking code,

CAN BE SEEN ON SHARP, TOSHIBA, PANASONIC Japan models
After Inverter_on, if it turns out BL doesn't turn on..........

 --------------------------------------------------------------------------------------------------------------------------------------

 How the microcontroller work process starting from the moment the electricity is plugged in so that the screen can turn on to output an image.

In the CRT TV technique  as example , this is the same as the work process, starting from the electricity being plugged in until the Flyback bursts and the CRT screen turns on.
 

This time we will discuss the problem of processing the VIDEO image signal so that the motherboard can output the LVDS image signal to be fed to the Tcon input. To make it easier to understand, we made a simple Main Block Diagram on the VIDEO image signal process on the Motheboard.

 

 

No.1  ANALOG Input.

 

 Analog input can be various, each model can be different.
Input signals from the RF antenna, Video Composite (Y, Cr, Cb) or Video-in are processed first by the VIDEO DECODER section to obtain an RGB signal.
 
No.2 PC (RGB) Input
Tube television hardly recognizes this type of input, namely analog RGB input. Through this input TV LCD / LED can be used as a PC computer monitor
 
No.3 A / D Converter.
Here the Analog RGB signal needs to be converted into a Digital RGB signal before entering the next process.
 
No.4 HDMI
HDMI is a digital data interface communication standard for Digital Audio / Video equipment. Other equipment which has an HDMI output can be connected directly without going through the Converter A / D circuit.
 
No.5 SCALER
This is a vital part of the motherboard's digital image signal processing before it is fed to the LCD panel.
In the Crt TV technique, RGB signals can be connected directly to all types of Crt. Want big or small crt. Want low resolution or high resolution CRT, everything can be done without the need for changes (converted)
 
In different LCD techniques.
There are various kinds of video input FORMAT with different image resolutions. Suppose there is a PAL video signal. NTSC, SECAM, MP4, GAME etc.
While the Lcd panels are made with different resolutions, such as HD, FHD, K4

 

 

 

 The input RGB digital video signal cannot be fed directly to the panel. Each format must be changed (converted) first to match the panel resolution used. That's what SCALER is for.
Input resolution is generally lower than panel resolution. Because of that Scaller is sometimes also called UpScaler Conversion.
In this section also the ASPECT RATIO video image signal can be changed in appearance size, for example a 4: 3 size TV image is changed to a wide 16: 9 size etc.
No.6 RAM
In the process of working, Scaler requires the help of high capacity RAM memory ic, which is sometimes called DDR RAM or SDRAM. Input digital data cannot be directly displayed to the output section. The input data is written first to IC RAM during the process, then after it is perfect, it is read to be outputted.
The higher the image resolution, the greater the capacity of the IC RAM that is bleached. RAM is integrated internally with the ic chip. While external RAM, sometimes there are motherboards that use only one piece, and sometimes there are those that use two.
IC Chip with external RAM communication with each other using several lines. Sometimes it is found that one of the paths has a problem, such as the R value is delayed, resulting in a defective image / osd.

 

 

No.7 LVDS.
Moving image data is a data transfer that requires very high speeds. The higher the image resolution, the higher the data transfer speed required. This causes various kinds of problems, such as (a) the need for more band-width, (b) the use of more electrical power, (c) causing high frequency noise interference.
LVDS or Low Voltage Differential Signaling is a data-transfering system technology that is able to answer the problems mentioned above.
LVDS characteristics are:
 Data-transfer at high speed
 The amplitude of the data signal is small, about 200 to 300 millivolts
 Low power requirements
 Little noise
 Works at very low low voltage
 Uses a pair of twisted wires and does not use ground as the reference signal
 The data sent is serial-data, so it can reduce the number of connector cables
Here RGB digital data is converted (encoded) by the LVDS Transmitter to become an LVDS data signal. The LVDS data is an analog signal, so a low frequency oscilloscope can track its presence.
Therefore, the LVDS data will be received by the LVDS Receiver and converted back (decoded) into a digital RGB signal.

 

 

 SOME EXAMPLES OF DAMAGE TO PICTURE SIGNAL LINE.
IC Chip with external RAM communication with each other using several lines. Sometimes it is found that one of the paths has a problem, such as there is an R value being delayed, resulting in a defective image / osd.
Image / OSD defects can sometimes also be caused by Vcc ic RAM drops.
The LVDS data path is damaged or cut sideways, causing the image to color way, depending on which path is broken.
Damage to the LVDS line can also cause the image to become out of sync (collapsing), because there is also a vertical / horizontal synchronization path. Seing found at old SONY.
Understand the example of a motherboard block. Then we will know which part we think is problematic. For example the HDMI input is OK no problem. While the other Input2 has a problem. So it is clear here that the damage is in the DECODER section.

Flash memory ic data also plays a role in determining the working system of the Scaler. Therefore, FW data errors can cause defective images.

 

REPAIRING / SERVICING LTJ400HV01-J LCD PANEL FAULTS

The following explanations are only for the panel with code LTJ400HV01-J. It does not work for different panels.


PROBLEM ------> The picture is flickering or shows / looks  double:

In order to determine which side of the panel the problem originates from, first remove the left film that connects the t-con card to the panel from both the t-con and the panel and run the TV. If the image displayed on the screen is correct, the right side of the panel is defective. If the image is the same, put the left film back on both the t-con card and the panel, and this time remove the right film. If the image improves, the problem is with the left side of the panel.


To fix the problem, remove the RM2 and RM5 resistors on the panel board. If the image is not improved in this state, remove the RM3 and RM6 resistors. If the image is not improved in this state, remove the RM4, RM7 resistors. If the image is not improved in this state, remove the RM1 resistor. The image should have improved with all resistors removed. If the image is correct, replace the resistors you removed starting from the beginning in pairs and check the image again each time. If the problem occurs when you put back the resistor series, leave that series idle. Remember to replace all resistors except the series causing the problem.

REPAIRING / SERVICING LTF400HM03 LCD PANEL FAULTS

The explanations below are only for the LTF400HM03 coded panel. It does not work for different panels.


 PROBLEM ------ > After a while, the picture flickers and starts showing double frames:

 In order to determine which side of the panel the problem originated from, first remove the left film that connects the t-con card to the panel from both the t-con and the panel and run the TV. If the image displayed on the screen is correct, the right side of the panel is defective. If the image is the same, attach the left film to both the t-con card and the panel, and this time remove the right film. If the image improves, the problem is with the left side of the panel.

  

Remove the RM1, RM2, RM3, RM4, RM5, RM6 and RM7 resistors on the panel board to fix the problem on the right. If the image did not improve in this state, replace the resistors you removed one by one and check the image again each time. If a problem occurs when you wire a series of resistors, leave that series idle. Remember to replace all resistors except the series causing the problem.
You need to use the same method to fix the problem on the left.

 

 Although the flickering problem has been eliminated, if there are horizontal lines on the screen, you should make the changes in the picture.

 

LCD PANELS T-CON UNITS TROUBLESHOOTING SERVICE FAULT NOTES

The most common fault in all T-con cards is capacitor failure. First, check the short circuit on the T-con board that you think is defective.

The Tcon board provides the video generated by the motherboard to be transferred to the panel, as well as generating the voltages the panel needs to operate.

Depending on the type of panel used, it is transferred from the 5V 3V3 16V and 26V tcon card to the panel. These voltages may be missing or more depending on the panel type. Tcon converts the 5V or 12V supply from the motherboard to the voltages required by the panel via the DCDC converters on it.
Some tcon cards work with 2 LVDS cables from the motherboard. Tcon feed is transmitted from only one of these cables. In televisions with 3D feature, 12V is transmitted from the mainboard to the tcona via a socket other than the LVDS cable. Consider this when making repairs.

If there is no 5V or 12V supply from the motherboard, check the "PANEL POWER" circuit on the motherboard. Transistors in this circuit can malfunction.
If Tcon supply is available but 16V and 26V are not available, check the inputs and outputs of the DCDC converter ICs. These integrated circuits may fail due to heat. These converters will not be activated until the "PANELON or PANELCTL" signal comes from the motherboard. In some tcones, if the panel is not connected to the tcon, tcon does not work.

If there are voltages but there is no picture, measure the data signals transmitted from the motherboard to the TC. Be careful while taking this measurement. If the probe causes a short circuit, the motherboard panel may malfunction. If you can measure a voltage between 1V2 and 1V6 on the data lines, it means that data signals are being sent from the motherboard to the tcona.
After that, what you need to do is to follow the voltages transmitted from the controller to the panel on the panel control card. If the fuses in the panel control card are good, replace the tcon card. If the fuses are blown or if heating / corrosion / oxidation has occurred in the smd parts, the panel is defective.

4046NN-MB4C6LV0.6
 
There's voice but no image. The television switches to standby after a while: ic29 (FDS4435) is defective.

V315B3-C04
No picture white screen: Q2 (A18E P type) is defective.

46T12-C01
The picture is broken prematurely: Q201 (AO3041A) is out of order.
6870C-0140B
No display: R128 (82Ohm) faulty.

T260XW01
Supply Voltage: 5 volts

 

 1- U402 AN1702; will cause no video failure.
2- U202 MAX1889E; It regulates 5 volts and produces the voltages that the tcon needs. If this IC is faulty, tcon will not work.
3- U301 FPD87352AU; will cause no image or image negative malfunction.
4- U302 RAM; causes frostbite in the image.



T296XW01-007
Supply Voltage: 12 volts

 

 1- U402 AN1702; will cause no video failure.
2- U303 EPROM; causes no picture or white screen malfunction.
3- U301 FPD87352B; will cause no image or image negative malfunction.
4- U302 RAM; causes frostbite in the image.
5- U901 U911 9743A; It regulates 12 volts and produces the voltages that the tcon needs. If these IC are faulty, tcon does not work.




T296XW01-011
Supply Voltage: 12 volts
T296XW01-011
1- U301 FPD87352B; will cause no image or image negative malfunction.
2- U302 RAM; causes frostbite in the image.
3- U901 U911 9743A; It regulates 12 volts and produces the voltages that the tcon needs. If these ICs are faulty, tcon does not work.
4- U501 EL5420; will cause no video failure.
5- J501; If there is a problem with the pins, the image will vibrate / wiggle.






V315B3-C01
Supply Voltage: 12 volts
v315b3-C01
1- U6 HX8915 GAMMA; will cause no image or image negative malfunction.
2- U3 CM1682A; causes freeze-up or no-image failure.
3- U4 EPROM; causes no picture or white screen malfunction.
4- UP1 TPS65161; It regulates 12 volts and produces the voltages that the tcon needs. If this IC is faulty, tcon will not work.
 VDD25: 2V5
 V12V: 12V
 VAAP: 13V5
 VGC: -5V
 VGH: 23V







V420H1-CO7
Supply Voltage: 12 volts
v420h1-C07
1- U3 U4 RAM; causes frostbite in the image.
2- U16 CM2679B; will cause no image or image negative malfunction.
3- U7 I7868A GAMMA; will cause no image or image negative malfunction.
4- UP1 TPS65161; It regulates 12 volts and produces the voltages that the tcon needs. If these IC are faulty, tcon does not work.
MDK336V-0
Supply Voltage: 12 volts

MDK336V-0
1- IC6 BD8161; It regulates 12 volts and produces the voltages that the tcon needs. If these IC are faulty, tcon does not work.
2- IC2 TCON102A; no image or image causes negative or rainbow glitch.
3- IC4 EPROM; causes no picture or white screen malfunction.
4- IC5 BUF12800 GAMMA; will cause no image or image negative malfunction.

TX80012VC
Supply Voltage: 12 volts
TX80012VC
1- IC200 8018SA; It regulates 12 volts and produces the voltages that the tcon needs. If these IC are faulty, tcon does not work.
2- IC1002 TCON21.6; no image or image causes negative or rainbow glitch.
3- IC1003 XCON-1; will cause no video failure.
4- IC1001 IC1001 RAM; causes frostbite in the image.
5- IN74VHC74D; will cause no video failure.
V260B1-C01
Supply Voltage: 5 volts

V260B1
1- U3 CM1671; will cause no video failure.
2- U5 HX8904; It is used to amplify GAMMA signals. will cause no image or image negative malfunction.
3- U8 3V3 IC; Regulates 3V3 voltage. causes various display problems. for example "freezing-silent-recovery when warmed".
4- Q3 P2003BVG; It regulates 5 volts and produces the voltages that the tcon needs. If this IC is faulty, tcon will not work.
4- U11 DCDC CONVERTER; It produces voltages required by the panel by regulating 5 volts. If this IC is faulty, tcon will not work.

V320B1-C03
Supply Voltage: 12 volts
V320B1
1- U1 U2 RAM; causes frostbite in the image.
2- U3 CM2681AKQ; causes various display problems or no video failure. for example "freezing-silent-recovery-on-warming-horizontal vertical lines".
3- U5 EPROM; causes no picture or white screen malfunction.
4- U6 SL1014I GAMMA; will cause no image or image negative malfunction.
5- DCDC CONVERTER; It produces voltages required by the panel by regulating 12 volts. If this IC is faulty, tcon will not work.

V296W1-C1
Supply Voltage: 12 volts
V296W1
1- U1 U2 U3 RAM; causes frostbite in the image.
2- U4 CM2561BKQ; causes various display problems or no video failure. for example "freezing-silent-recovery-on-warming-horizontal vertical lines".
3- UP1 FA3269AV DCDC CONVERTER; It produces voltages required by the panel by regulating 12 volts. If this IC is faulty, tcon will not work.
 CVOFT: 0V75
 R17: 2V5
 VDA: 13V5
 VDD: 20V
 VDL: -5V

T370XW01
Supply Voltage: 12 volts
t370xw01
1- U22 RAM; causes frostbite in the image.
2- U21 AUO016K1; causes various display problems or no video failure. for example "freezing-silent-recovery when warming-horizontal vertical lines".
3- U301 BD8156EFV DCDC CONVERTER; It produces the voltages required by the panel by regulating 12 volts. If this IC is faulty, tcon will not work.
4- Q304 RSS085: causes no video failure.

T315XW01
Supply Voltage: 12 volts
t315xw01
1- U3 ADD8709: causes no display failure.
2- U11 EPROM; causes no picture or white screen malfunction.
3- U9 AUO016K1; causes various display problems or no video failure. for example "freezing-silent-recovery when warming-horizontal vertical lines".
4- U2 AAT1110 DCDC CONVERTER; It produces the voltages required by the panel by regulating 12 volts. If this IC is faulty, tcon will not work.






6870C-0011D LC260W01-A5
Supply Voltage: 12 volts
6870C-0011D

6870C-0158A
No picture white screen: No VGHM voltage, U7 (RT8901) faulty.





 

260W2C4LV1.0
Supply Voltage: 5 volts
260W2C4LV1
Tcon signals and voltages
 VON VGH VGON VDDG: It is between 20V and 30V.
 VOFF VGL VGOFF VEEG: It is between -5V and -7V.
 VDD Vlogic Vddd Dvdd: 3V3 volts, but if it is VDD25 or VDD18, it is 2V5 or 1V8.
 VDA Avdd Vdda Vsource: It is between 13V and 20V.
 AGND: Chassis.
 BGND: Supply chassis.
 GND: Chassis.
 PGND: Supply chassis.
 STV: Vertical Synchronization Input. It depends on the STVP signal.
 STVP: Scan Driver High Voltage Output.
 CPV1: Vertical Timer Signal Input. Sets the timing of the CKV1 and CKVB1 signals.
 CPV2: Vertical Timer Signal Input. Sets the timing of the CKV2 and CKVB2 signals.
 CPV3: Vertical Timer Signal Input. Adjusts the timing of the CKV3 and CKVB3 signals.
 CKV1: Vertical Scan Driver High Voltage Output Signal.
 CKV2: Vertical Scan Driver High Voltage Output Signal.
 CKV3: Vertical Scan Driver High Voltage Output Signal.
 CKVB1: Vertical Scan Driver High Voltage Reverse Output Signal.
 CKVB2: Vertical Scan Driver High Voltage Reverse Output Signal.
 CKVB3: Vertical Scan Driver High Voltage Reverse Output Signal.
 CKVCS1 CKVBCS1: Signal sharing. It connects the CKV1 and CKVB1 signals together as needed.
 CKVCS2 CKVBCS2: Signal sharing. It connects the CKV2 and CKVB2 signals together as needed.
 CKVCS3 CKVBCS3: Signal sharing. It connects the CKV3 and CKVB3 signals together as needed.
 BOOST: Main Supply Input. It depends on VMAIN.
 COMP: Fault Amplifier Reference Input.
 DISH: Voltage Discharge Connection. It discharges the voltage in case of supply failure.
 DLY: Initial Delay Adjuster.
 EN: Activates Scan Integration. It works simultaneously with DLY.
 FB: Feedback Input. It has a supply of around 1V24.
 GOFF: CKV is the - (negative) supply of CKVB and STVP signals.
 GON: CKV is the + (positive) supply of CKVB and STVP signals.
 IN: Regulator Supply Input.
 LX: Switching Node.
 NEG: Amplifier Reverse Input.
 OE: Active-High Gate-Pulse Output Enable. I could not translate it verbatim.
 OECON: Timing the OE Signal.
 OUT: Adjustable Full Scale Current Output. Adjusts the voltage of the POS Input.
 POS: Amplifier (Amplifier) Voltage Input.
 SET: Adjustable Full Scale Current Input.
 VCOM: Amplifier Voltage Output.

REPAIRING / SERVICING LTA260AP02 LCD PANEL FAULTS

The explanations below are only for the LTA260AP02 coded panel and 260AP02C2LV0.2 coded t-con card. Absolutely useless on different panels and t-con cards.


PROBLEM ----->  The screen has a problem like the picture (streaks or distortions):

IC4 integrated in the T-con card has failed. If you are not able to replace the IC, replace the t-con board.

There is no sound at first startup, but after a while, vertical colored lines appear on the screen:
IC7 on the T-con card may have failed. If you are not able to replace the IC, replace the t-con board.


Other PICTURE malfunctions;

If the T-con card is intact but there are streaks or distortions in the image (excluding dead pixels), cut the lines of CKV1 and CKVB1. If the problem persists, disconnect the CKV2 and CKVB2 lines as well. If the problem persists, reconnect the CKV1 and CKVB1 lines. CKV2 and CKVB2 remain cut.

If the display problem persists, cut the STVP1 lines. Try to fix the problem by trying different combinations, but cut or combine the lines with the same name at the same time. Do not short-circuit the signals when you do it, just connect the circuit you cut back.

 

REPAIRING / SERVICING LTJ400HM03 LCD PANEL FAULTS

The explanations below are only for the LTJ400HM03 coded panel and S100FAPC2LV0.3 coded t-con card. Absolutely useless on different panels and t-con cards.



PROBLEM ------> The picture is flickering and shows double picture:

 

In order to determine which side of the panel the problem originates from, first remove the left film that connects the t-con card to the panel from both the t-con and the panel and run the TV. If the image displayed on the screen is correct, the right side of the panel is defective. If the image is the same, put the left film back on both the t-con card and the panel, and this time remove the right film. If the image improves, the problem is with the left side of the panel.

Remove the RM2 and RM5 resistors on the panel board to fix the problem on the right. If the image is not corrected, remove the RM3 and RM6 resistors. If the image is not clear, remove the RM4 and RM7 resistors. If the problem still persists, remove the RM1 resistor as well. When these resistors are removed, the image needs to be improved, but there may be problems other than the main fault in the image. To fix these problems, wire the resistors you removed in order (two resistors separately) and check the image again each time. If a problem occurs when you wire a series of resistors, leave that series idle. Remember to replace all resistors except the series causing the problem.

You need to use the same method to fix the problem on the left. By looking at which signals the resistors on the right side belong to, you can find out which resistors belong to which signal according to the signal names printed on the card on the left.


 STVP : RM1
CKV1 : RM2
CKVB1 : RM5
CKV2 : RM3
CKVB2 : RM6
CKV3 : RM4
CKVB3 : RM7

REPAIRING / SERVICING LTA400HM04 LCD PANEL FAULTS

The explanations below are only for the LTA400HM04 coded panel. It does not work for different panels.

PROBLEM ------ > The picture flickers:

In order to determine which side of the panel the problem originated from, first remove the left film that connects the t-con card to the panel from both the t-con and the panel and start the television. If the image displayed on the screen is correct, the right side of the panel is defective. If the image is the same, attach the left film to both the t-con card and the panel, and this time remove the right film. If the image improves, the problem is with the left side of the panel.

If the problem is on the right side, cut the signals CKV1 and CKVB1, CKV2 and CKVB2, CKV3 and CKVB3 in two respectively. If the image does not improve, also cut the STVP signal. When the picture is correct, reconnect other signals except for the group of signals you cut last.

If the problem is caused by the left side, you can cut the signals by sticking a thin tape between the film connected to the t-con board from the panel board and the socket to cut the signals.

If you place the LTA400HM04-left-Tape properly on the appropriate pins, the image will improve.