REPAIRING / SERVICING TV LG 43LK5990PLE

Technical description and composition of LG 43LK5990PLE TV, type of panel and modules used. Module composition.
Composition
Specifications
LG 43LK5990PLE
LCD TV LED Smart 43LK5990 | Year of manufacture: 2018
Screen diagonal: 42.5" (108 cm)
Screen format: 16:9
Resolution: 1920x1080
Frequency refresh rate:     50Hz
LED backlight: aye, Direct LED
Smart: yes. Wi-Fi support: yes
Operating system: webOS
Supports HD: 1080p Full HD, HDR
Progressive scan: yes
Digital tuner: DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2
Teletext: Yes
Multimedia: MP3, WMA, MPEG4, HEVC (H.265), DivX, MKV, JPEG
Stereo sound: there is
Sound power: 10W (2x5W)
Acoustics: two speakers
Interface: AV, component, HDMI x2, USB, Ethernet (RJ-45), Wi-Fi 802.11ac, Miracast
Headphone jack: yes
TV weight: with stand: 8.1 kg
Without stand: 7.6 kg
Dimensions: with stand 976x628x218mm
without stand 976x583x70mm
Find out more...
LG 43LK5990PLE

LG LED
Model: 43LK5990PLE

Chassis/Version: CHASSIS LJ8

Panel: AC430DUN-SLDM2_RA

LED backlight: 17Y 43inch_ A-Type LED_ARRAY_REV0.0_170632

T-CON: 6870C-0532A

LED driver (backlight): integrated into PSU

PWM LED driver: LC5910

MOSFET LED driver: TO-252

Power Supply (PSU): EAX67264001 LGP43DJ-17F1 PLDF-L602A

PWM Power: PFC, PWM

MOSFET Power: TO-252

MainBoard: EAX67703503 (1.1)

IC MainBoard: CPU, eMMC, SPI Flash, DRAM, AUDIO, DC/DC

MainBoard: TDJA-G601D
General advice about LCD LED TV repair
Possible trouble spots

- LG 43LK5990PLE TV does not turn on, does not respond to the remote and control panel buttons, does not shine or blink indicators.

Most often with such manifestations turns out to be faulty main power module EAX67264001. It is necessary then to measure its output voltages and in case they are missing, check the power switches (TO-252) and the rectifier diodes of the converters for possible short circuits.
At breakdown of semiconductors in the secondary circuits of any converter, as a rule, it can operate in the emergency short-circuit mode without output voltages, and at short circuit in the elements of the primary circuit most often immediately burst the mains fuse and less often the current sensor at the source of the key.
Breakdown of Mos-Fet switches, used in pulse sources, is often caused by failure of other elements, for example, in PWM regulator supply circuit, in frequency-retaining or damping circuits, as well as in the Negative Feedback Stabilization. PWM PFC, PWM chips are usually checked by replacing them with new or known good ones.

- No picture, but there is sound and reaction to remote control. Or for a second the image may appear right after turning on.

The defect in these cases is usually the most probable in the nodes of the display matrix backlight. Often the cause is a faulty LED (breakage, short circuit...), or connectors of bars (strings) 17Y 43inch_ A-Type LED_ARRAY_REV0.0_170632, less often faulty is the LED-driver.
It is better to use a power supply with a maximum voltage of 200v to check the condition of the LED circuit. It is not recommended to use any voltage sources for this purpose. You can check each LED individually with a simple Chinese multimeter (9 volt) in P-N junction test mode. If you connect the red probe of the multimeter to the anode of the LED and the black to its cathode, then the 3 volt LED will light up slightly and in the opposite direction you will find the faulty junction of the stabilizer. The functionality of the PN junction of the stabilizer is indirectly an indication of the functionality of the LED.

READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.

- The TV set does not turn on, the LED indicates standby or operation mode, or blinks.

Repair or diagnostic of motherboard EAX67703503 should be started from checking stabilizers and power converters necessary to power the chips and matrix. If necessary, software (software) should be updated or replaced. Complex repair of MB (SSB) is possible only in the conditions of the service center with the necessary equipment. Checking or replacing the CPU, eMMC, SPI Flash, DRAM, AUDIO, DC/DC elements requires the necessary training and professional skills to repair the modules at the component level. Problems related to the use of BGA soldering technology can sometimes be diagnosed by the heating method.

If the TV works normally from external devices, but does not tune to the TV channels, the TDJA-G601D tuner may be malfunctioning. In these cases you should first make sure that there is power to the corresponding pins of the tuner. Also make sure that the tuner and the processor are communicating via the I2C bus. Sometimes the reason of the tuner malfunction can be a software error.

Warning. Users and owners of TV sets 43LK5990PLE, not having the appropriate qualification, knowledge and experience, strongly recommend not to try to repair the unit yourself in order to avoid the negative consequences that can lead to complete unrepairable device.

 



Repair of backlight EAX67264001 LGP43DJ-17F1, LC5910. Information from the master.

Decreased backlight current from 320 mA to 270 mA - increased R801 0.8 Ohm resistor to 1 Ohm in the backlight current sensor on the power supply board EAX67264001.
Backlight driver current limitation. EAX67264001 LGP43DJ-17F1, LC5910. General recommendations.

To reduce the backlight current in LGP43DJ-17F1 EAX67264001 (1.5) TVs with the LC5910 LED driver chip, you can increase the current sensor resistance R801 at the source of the converter power switch proportionally.
LGP43DJ-17F1 current backlight

A PDF document of the LC5910S is included.

  Ways to limit the current in LED backlight drivers:

There is a lot of information on the Internet about ways to limit the current in the LED backlighting for different TVs and LED drivers. A lot of it is written plausibly but sometimes it is written by people far from electronics in order to publish any popular content on hot topics to boost web-sites ratings.

It's impossible to talk about each case separately within one article, because even similar models may have different panels and different boards with their own driver variants. But there are basic principles that are clear to craftsmen with even minimal knowledge and skill.

Other popular, complex and controversial current limit cases will be published as information becomes available.
There are three basic ways to reduce the backlight current.

1. By increasing the resistance of the LED current sensor - a low-resistance measuring resistor in the cathode (LED-) circuit.
2. Increasing the ratings of the resistors on the ISET (current setting) input of the LED driver chip.
3. changing the resistor ratings in the divider on the ADIM (Dimming) control input.

The fundamental difference between input ISET and ADIM is that ISET - input inverted, as FB, and ADIM - direct.

More on MainBoard Repair

The MainBoard EAX67703503 is shown in the figure below:

EAX67703503

MainBoard Appearance

 

:

EAX67264001.

The main features of the LG 43LK5990PLE device:

A matrix (LED panel) AC430DUN-SLDM2_RA is installed.
Timing Controller (T-CON) 6870C-0532A is used to control the matrix.
To power the backlight LEDs a converter combined with a power supply is used, controlled by the LC5910 PWM controller. As the power elements of LED-driver are used switches of TO-252 type.
Forming of the necessary supply voltages for all LG 43LK5990PLE TV nodes is made by EAX67264001 power supply module, or its analogues with the use of PFC, PWM chips and TO-252 type power keys.
MainBoard - the main board (motherboard) is an EAX67703503 module, using CPU, eMMC, SPI Flash, DRAM, AUDIO, DC/DC and other chips.
The TDJA-G601D tuner provides TV program reception and channel tuning.

Instructions and updates

There are downloadable files for the 43LK5990PLE model from the manufacturer:

Update and instruction files:
File Description File Name Type Date Size
SW File (Version 05.10.30) . Firmware (USB) Software_File(Version_05.10.30).zip zip 26.03.2020 824985K
Compatible with 32LK540BPLA, 32LK6100PLB, 32LK610BPLB, 32LK615BPLB, 32LK6190PLA, 32LK6200PLA, 43LK5400PLA, 43LK5900PLA, 43LK5910PLC, 43LK5990PLE, 43LK6000PLF, 43LK6100PLA, 43LK6100PLB, 43LK6200PLD, 49LK5400PLA, 49LK5900PLA, 49LK5910PLC, 49LK6000PLF, 49LK6100PLA, 49LK6100PLB, 49LK6200PLD.
SW File (Version 05.10.30) . TV_Software_Update_Guide_v3.pdf PDF 26.03.2020 2014K update instructions

Manuals and User Manuals:
Document Language Date Size
Quick Start Guide English - English,Estonian,Latvian,Lettish,Lithuanian,Russian 11.05.2020 55 037K
Quick Start Guide English - English,Estonian,Latvian,Lettish,Lithuanian,Russian 11.05.2020 No data
Quick start guide English - English 05.31.2018 4067K

You can download the files from the manufacturer's website for the model 43LK5990PLE.


LG 43LK5990 LCD TV with AC430DUN-SLDM2_RA, 42.5" (108 cm) diagonal in 16:9 aspect ratio. The LCD-panel implements the principle of direct display backlighting with a rear arrangement of LEDs - Direct LED.
Matrix AC430DUN-SLDM2_RA and MainBoard software EAX67703503 provide for viewing shows and movies in high quality HD resolution 1920x1080 pixels in 1080p (Full HD) graphic decomposition. Image processing is made by modern technology High Dynamic Range (HDR) with an extended range of brightness gradation.
The TV model 43LK5990 has built-in SMART software and webOS operating system. Connection to the network can be made via Wi-Fi wireless connection. Supported media formats: MP3, WMA, MPEG4, HEVC (H.265), DivX, MKV, JPEG.
The speaker system sound power of 10 W (2x5 W) is provided by two speakers. NICAM stereo sound processing and Sound Surround surround function are used.
Communication with other devices via an external interface is supported by standard input and output sockets: antenna input (RF), AV, component, HDMI x2, USB, Ethernet (RJ-45), Wi-Fi 802.11ac, Miracast. There is a headphone jack. The digital tuner receives DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 TV channels.

The TV uses the EAX67264001 power supply.

Overall dimensions: with stand 976x628x218 mm, without stand 976x583x70 mm.

TV weight: with stand: 8.1 kg, without stand: 7.6 kg.

Warning. The panel AC430DUN-SLDM2_RA of LG 43LK5990 LED TV is an expensive and unreliable part of it.
Avoid any kind of impact on the glass and pressure on the screen surface to avoid damaging the LED panel!
It is also not safe to get liquid on the screen. Sometimes one drop is enough if it drips down the glass onto the cables and the TV becomes unrepairable.

REPAIRING / SERVICING TV LG 43LK5910PLC

Technical description and composition of LG 43LK5910PLC TV, type of panel and modules used. Module composition.
Composition
Specifications
LG 43LK5910PLC.
LCD TV LED Smart 43LK5910 | Year of manufacture: 2018
Screen diagonal: 42.5" (108 cm)
Screen format: 16:9
Resolution: 1920x1080
Frequency refresh rate:     50Hz
LED backlight: aye, Direct LED
Smart: yes. Wi-Fi support: yes
Operating system: webOS
Supports HD: 1080p Full HD, HDR
Progressive scan: yes
Digital tuner: DVB-T, DVB-T2, DVB-C, DVB-S
Multimedia: MP3, WMA, MPEG4, Xvid, MKV, JPEG
Audio Stereo: There is
Sound Power: 10W (2x5W)
Acoustics: two speakers
Interface: AV, component, HDMI x2, USB, Ethernet (RJ-45), Wi-Fi 802.11ac, Miracast
Headphone jack: Yes
Find out more...
LG 43LK5910PLC

LG LED
Model: 43LK5910PLC

Chassis/Version: CHASSIS LJ8

Panel: AC430DUN-SLDM3_RA

LED backlight: UF64_UHD_A

T-CON: 6870C-0532A (6871L-3806L)

LED driver (backlight): integrated into PSU

PWM LED driver: LC5910 SO-8 Step-Down

MOSFET LED driver: TO-252

Power Supply (PSU): EAX67264001 (1.5) LGP43DJ-17F1

PWM Power: PFC, PWM

MOSFET Power: TO-252

MainBoard: EAX67703503 (1.1)

IC MainBoard: CPU, eMMC, SPI Flash, DRAM, AUDIO, DC/DC

MainBoard: TDJA-G601D
General advice about LCD LED TV repair
Possible problems

- LG 43LK5910PLC does not turn on, the buttons and remote does not respond, the indicators on the front panel are not lit or blinking.

Usually with such manifestations defect is caused by faulty elements in the main power module EAX67264001. It is necessary to check the presence of its output voltages and in case of their complete absence check the power switches (TO-252) and the rectifier diodes for possible short circuits.
With any breakdown of semiconductors in the secondary circuits, the inverter can usually operate normally in the emergency short-circuit mode. There are no output voltages in this case. And when a short circuit occurs in the power elements of the primary circuit, as a rule, the mains fuse and rarely the current sensor at the source of the switch break down.
Breakdown of Mos-Fet switches, used in pulse sources, is often caused by failures of other elements, for example, in the PWM regulator supply circuit, in frequency-retaining or damping circuits, as well as in the Negative Feedback Stabilization. PWM PFC, PWM chips are usually checked by replacing them with new or known good ones.

- There is no picture, but there is sound and all other TV functions work. The picture sometimes appears for a second immediately after switching on and then disappears.

READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.

Usually in such cases there is no backlighting of the LED panel (matrix). The cause may be a breakage of the backlight LEDs, in the stabilization of their power supply, or in a violation of the contact connections of the string connectors.
To check the LED strips, to open all the LED transitions, you need a few tens of volts or more, it is best to use a current source for such purposes. Breakage of several PN-junctions connected in series cannot be detected with a multimeter or a tester. In such cases, you need to open the panel and check each LED. If your multimeter can't open the transitions of the LEDs in forward bias, you can sometimes detect the PN junction of a protective stabilizer by connecting the probes in the opposite direction. If the regulator is open or broken in K/Z, then the LED is faulty and needs to be replaced.

- LED blinks or lights constantly, TV set won't turn on, remote control won't respond.

Repair or diagnostic of motherboard EAX67703503 should begin with checking the stabilizers and power converters necessary to power the chips and matrix. If necessary, the software (software) should be updated or replaced. When repairing the MB board, check its components CPU, eMMC, SPI Flash, DRAM, AUDIO, DC/DC. Defective elements should be replaced. If the chips with BGA soldering technology are used, the problem in its implementation is detected by the method of local heating of the chip.

If there is no TV channel reception, but the TV set is working properly from external devices, you must first check the supply voltage of the TDJA-G601D tuner and update the software. Pulses of the I2C bus communication should be checked with an oscilloscope.

Warning to TV Owners! The attempts to repair LG 43LK5910PLC by yourself are not recommended by the manufacturer and can cause serious negative consequences!


Repair after repair of backlight EAX67264001 LGP43DJ-17F1, LC5910. Information from the master.

Decreased backlight current from 620 mA to 280 mA - I increased R801 0.8 Ohm resistor rating to 2.2 Ohm in the backlight current sensor on EAX67264001 power supply board.
Limiting the backlight driver current. EAX67264001 LGP43DJ-17F1, LC5910.

General recommendations.

Reduce backlight current from 620 mA to 280 mA - I increased the R801 0.8 Ohm resistor to 2.2 Ohm in the backlight current sensor on the power supply board EAX67264001.
Limiting the backlight driver current. EAX67264001 LGP43DJ-17F1, LC5910. General recommendations.

To reduce the backlight current in LGP43DJ-17F1 EAX67264001 (1.5) TVs with the LC5910 LED driver chip, you can increase the current sensor resistance R801 at the source of the converter power switch proportionally.
LGP43DJ-17F1 current backlight

A PDF document of the---------------------->  LC5910S is included.

  Ways to limit the current in LED backlight drivers:

There is a lot of information on the Internet about ways to limit the current in the LED backlighting for different TVs and LED drivers. A lot of it is written plausibly but sometimes it is written by people far from electronics in order to publish any popular content on hot topics to boost web-sites ratings.

It's impossible to talk about each case separately within one article, because even similar models may have different panels and different boards with their own driver variants. But there are basic principles that are clear to craftsmen with even minimal knowledge and skill.
Other popular, complex and controversial current limit cases will be published as information becomes available.
There are three basic ways to reduce the backlight current.

1. By increasing the resistance of the LED current sensor - a low-resistance measuring resistor in the cathode (LED-) circuit.
2. Increasing the ratings of the resistors on the ISET (current setting) input of the LED driver chip.
3. changing the resistor ratings in the divider on the ADIM (Dimming) control input.

More on MainBoard Repair

The MainBoard EAX67703503 is shown in the figure below:

EAX67703503

MainBoard Appearance

EAX67264001:

EAX67264001.

Main features of the LG 43LK5910PLC:

A matrix (LED panel) AC430DUN-SLDM3_RA is installed.
The matrix is controlled by the Timing Controller (T-CON) 6870C-0532A.
To power the backlight LEDs a converter combined with a power supply is used, controlled by a LC5910 SO-8 Step-Down PWM controller. As the power elements of the LED-driver switches of TO-252 type are used.
Necessary supply voltages for all LG 43LK5910PLC TV nodes are generated by the EAX67264001 power supply module or its analogues with the use of PFC, PWM chips and TO-252 type power keys.
MainBoard - the main board (motherboard) is an EAX67703503 module, using CPU, eMMC, SPI Flash, DRAM, AUDIO, DC/DC and other chips.
The TDJA-G601D tuner provides TV program reception and channel tuning.


Instructions and updates

There are downloadable files for the 43LK5910PLC model from the manufacturer:

Update and instruction files:
File Description File Name Type Date Size
SW File (Version 05.10.30) . Firmware (USB) Software_File(Version_05.10.30).zip zip 26.03.2020 824985K
Compatible with 32LK540BPLA, 32LK6100PLB, 32LK610BPLB, 32LK615BPLB, 32LK6190PLA, 32LK6200PLA, 43LK5400PLA, 43LK5900PLA, 43LK5910PLC, 43LK5990PLE, 43LK6000PLF, 43LK6100PLA, 43LK6100PLB, 43LK6200PLD, 49LK5400PLA, 49LK5900PLA, 49LK5910PLC, 49LK6000PLF, 49LK6100PLA, 49LK6100PLB, 49LK6200PLD.
SW File (Version 05.10.30) . TV_Software_Update_Guide_v3.pdf PDF 26.03.2020 2014K update instructions

Manuals and User Manuals:
Document Language Date Size
Quick Start Guide English - English,Estonian,Latvian,Lettish,Lithuanian,Russian 11.05.2020 55 037K
Quick Start Guide English - English,Estonian,Latvian,Lettish,Lithuanian,Russian 11.05.2020 No data
Quick start guide English - English 10.07.2020 6308K

You can download the files on the website of the manufacturer for the model 43LK5910PLC.


LG 43LK5910 LCD TV with AC430DUN-SLDM3_RA, 42.5" (108 cm) diagonal in 16:9 aspect ratio. The LCD panel implements the principle of direct display backlighting with a rear arrangement of LEDs - Direct LED.
Matrix AC430DUN-SLDM3_RA and MainBoard software EAX67703503 provide for viewing shows and movies in high quality HD resolution 1920x1080 pixels in 1080p (Full HD) graphic decomposition. Image processing is made by modern technology High Dynamic Range (HDR) with an extended range of brightness gradation.
The 43LK5910 has built-in SMART software and webOS operating system. Connection to the network can be made through Wi-Fi wireless communication. Supported media formats: MP3, WMA, MPEG4, Xvid, MKV, JPEG.
The sound system capacity of 10 W (2x5 W) is provided by two speakers. NICAM stereo sound processing and Sound Surround surround function are used.
Communication with other devices via an external interface is supported by standard input and output sockets: antenna input (RF), AV, component, HDMI x2, USB, Ethernet (RJ-45), Wi-Fi 802.11ac, Miracast. There is a headphone jack. The digital tuner receives DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 TV channels.

The TV set has the EAX67264001 power supply.

Warning. The AC430DUN-SLDM3_RA panel of the LG 43LK5910 LED TV is an expensive and unreliable part of it.
Do not allow any impact on the glass and pressure on the surface of the screen to avoid damage to the LED panel!
It is also not safe to get liquid on the screen. Sometimes one drop is enough if it drips down the glass onto the cables and the TV becomes unrepairable.

REPAIRING / SERVICING TV LG 32LF551C

 
Technical description and composition of LG 32LF551C TV, type of panel and modules used. Module composition.
Composition
Specifications
LG 32LF551C
LCD TV LED 32LF551C | Year of manufacture: 2015
Screen diagonal: 32" (81 cm)
Screen format: 16:9
Resolution: 1366x768
Refresh rate:     50 Hz
LED backlight: Yes, Direct LED
Support HD: 720p HD
Progressive scan: Yes
TV Standards: PAL, SECAM, NTSC
Digital tuner: DVB-T, DVB-T2, DVB-C
Teletext: Yes
DTV formats: 480i, 480p, 576i, 576p, 720p, 1080i, 1080p
Multimedia: MP3, WMA, MPEG4, DivX, MKV, JPEG
Sound stereo: there is
Sound Power: 10W (2x5W)
Acoustics: two speakers
Interface: AV, Component, HDMI x2, USB
Find out more...
LG 32LF551C

LG LED
Model: 32LF551C

Chassis/Version: LB56H

Panel: NC320DXN VSBP8

LED driver (backlight): integrated into PSU

PWM LED driver: BD559

MOSFET LED driver: 5N41

Power Supply (PSU): EAX66171501 (2.1) LGP32D-15CH1

PWM Power: SSC3S111

MOSFET Power: MDF11N65B

MainBoard: EAX66203805 (1.2)

IC MainBoard: CPU: LGE2136, SPI Flash: MX25L8035EM2I, EEPROM: 24C256, Audio: TAS5733

TP: TDJM-G301D
General recommendations for LCD LED TV repair
Possible problems

- LG 32LF551C TV does not turn on, does not respond to the remote and control panel buttons, the indicators are not lit or blinking.

With such manifestations, in some cases the power module EAX66171501 is defective. It is necessary to measure its output supply voltages, and in their absence check the serviceability of the power switches (MDF11N65B) converters and rectifier diodes on the probability of breakdown in the semiconductor PN-junctions.
If the semiconductors in the secondary circuits breakdown, the inverter can usually be short-circuited accidentally, and the mains fuse is often blown when the power elements in the primary circuit are shorted.
Mos-Fet switches used in switching power supplies usually fail due to the failure of other elements that can take it out of key mode, or cause it to exceed the maximum current or voltage. These may be the circuits feeding the PWM controller, the damping or frequency-retaining circuits, or the negative feedback elements in the stabilization circuit. PWM controllers (PWM) SSC3S111, if there is no external damage and short circuit between the pins, check by replacing with a known good.

- No picture, but there is sound and all other functions work. Sometimes image appears for a second and then disappears.

Failure in the majority of such cases is detected in the nodes and elements of LED panel backlight. The cause can be found in the failure of LEDs, in violation of the contact between the LED strips, or in providing them with power (LED-driver).
It is impossible to detect a breakage in the line of LEDs without disassembling the panel with a simple multimeter. LEDs are connected in series and to open their junctions you will need a voltage of several tens of volts. Ideally a current source would be suitable for this purpose. You can open up the panel and check each LED separately. Usually, Chinese multimeters will light up one 3 volt LED slightly if you connect the probes to it in the forward direction (red probe to the anode, black probe to the cathode). For twin 6-volt LEDs, the PN junction of its faulty stabilizer can be used as an indicator of the health of the LED. If the LED is faulty, its regulator will either be broken or it will be short-circuited.

If the LG 32LF551C has no picture but has sound, often the NC320DXN VSBP8 display backlight is just not working. And, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases you can see a faintly visible image when external light hits the screen.

To replace the LEDs requires disassembly of the LCD-panel NC320DXN - the process requiring a master of experience and skill. We do not recommend to perform such works by yourself to owners of TV sets and masters who have no experience in LCD panel repair.

READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.

If there is no image, but backlighting works - the screen becomes slightly lighter when the TV is turned on, and in the open TV you can see the light through the holes in the body of the panel.
In this case the panel may be defective - damage to the strips, cables, for example, as a consequence of moisture after an unsuccessful washing of the screen, the T-CON board (Timing Controller) may be defective. But quite often the MainBoard EAX66203805 is defective, and software failure is also possible.
Then first it is necessary to check the panel power supply voltage, fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within normal limits, it is necessary to trace by oscilloscope the LVDS signals from MainBoard EAX66203805, as well as synchronizing signals to the driver stubs.

Filled or unsuccessfully washed LED TV screens can be restored in about half of the cases, usually, if there is no significant damage in the cables and panel strips.

- The LED blinks or lights constantly, the TV set doesn't turn on, the remote control doesn't respond.

Repair or diagnosis of the motherboard EAX66203805 should begin with a check of the stabilizers and power converters needed to power the chips and matrix. If necessary, software (software) should be updated or replaced. Complex repair of MB board (SSB) in some cases is possible and practiced by repairmen. To do this, you should check and, if necessary, replace elements CPU: LGE2136, SPI Flash: MX25L8035EM2I, EEPROM: 24C256, Audio: TAS5733. Faulty BGA chips are usually easy to detect by warming them up.

If the TV set works fine with external devices but does not tune to the TV channels the TDJM-G301D tuner might be malfunctioning. In these cases you should first make sure that there is power to the corresponding pins. Also make sure that the tuner and the processor are communicating via the I2C bus. Sometimes a software malfunction can be the reason for the tuner malfunction.

To owners of a 32LF551C TV I recommend you to apply for repair only to a qualified specialist with the necessary experience! Attempting to repair yourself without the necessary knowledge and skills can lead to irreversible negative consequences!

DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>  LG 32LF551C Chassis LB56H.

 After repair of the backlight EAX66171501, BD559. Information from the master.

Decrease backlight current from 180 mA to 110 mA - replace R816 2.3 Ohm resistor at the source of converter key (current sensor) on EAX66171501 power supply board.
Driver current limitation. EAX66171501. General information.

To reduce the backlight current in LG TV's with the EAX66171501 (LGP32D-15CH1) power supply, you can increase the R816 2.3 Ohm current sensor resistance to 3 or 3.3 Ohm. The backlight current will decrease proportionally from the default 250mA to 200 or 180 mA respectively.
EAX66171501 current backlight.

 Ways to limit the current in LED backlight drivers:

There is a lot of information on the Internet about ways to limit the current in the LED backlighting for different TVs and LED drivers. A lot of it is written plausibly but sometimes it is written by people far from electronics in order to publish any popular content on hot topics to boost web-sites ratings.

It's impossible to talk about each case separately within one article, because even similar models may have different panels and different boards with their own driver variants. But there are basic principles that are clear to craftsmen with even minimal knowledge and skill.

Other popular, complex and controversial current limit cases will be published as information becomes available.
There are three basic ways to reduce the backlight current.

1. By increasing the resistance of the LED current sensor - a low-resistance measuring resistor in the cathode (LED-) circuit.
2. Increasing the ratings of the resistors on the ISET (current setting) input of the LED driver chip.
3. changing the resistor ratings in the divider on the ADIM (Dimming) control input.

The fundamental difference between input ISET and ADIM is that ISET - input inverted, as FB, and ADIM - direct.

 More on MainBoard Repair

The MainBoard EAX66203805 is shown in the illustration below:

EAX66203805

The EAX66203805 can be used in televisions:

LG 32LF564U (Panel LC320DXE (MG)(A3)), LG 42LF550V (Panel LC420DUE (MG)(A6)), LG 32LF560U ZB (Panel NC320DXN VSBP5 ), LG 42LF560V (Panel LC420DUE (MG)(A3)), LG 32LF562V (Panel NC320DUN-VBBP3 (EAJ63171201)), LG 32LF564V (Panel NC320DUN VBBP3), LG 32LF560V (Panel NC320DUN-VBBP3), LG 49LF620V 49LF620V-ZB (Panel LC490DUE (MG)(P2)), LG 42LF551C (Panel LC420DUE-MGA6).

Power Supply Unit Exterior

EAX66171501:

EAX66171501.

Main features of the LG 32LF551C:

NC320DXN VSBP8 matrix (LED panel) is installed.
To power the backlight LEDs a converter, combined with a power supply, controlled by PWM controller BD559 is used. As the power elements of the LED-driver are used switches type 5N41.
Necessary supply voltages for all LG 32LF551C TV sets are generated by the power module EAX66171501 or its analogues using SSC3S111 chips and MDF11N65B type power keys.
MainBoard - the main board (motherboard) is a module EAX66203805, using chips CPU: LGE2136, SPI Flash: MX25L8035EM2I, EEPROM: 24C256, Audio: TAS5733 and others.
The TDJM-G301D tuner provides TV program reception and channel tuning.


Instructions and updates

Last update (firmware) - latest firmware Software File Version 03.05.37
Software_File_(Version_03.05.37).zip. From 12/11/2015, size 57713K
Software_Upgrade_Guide(Italy).pdf. From 12/11/2015, size 653K

Update (firmware) to models: 28LF551C-ZA, 32LF510B-ZB, 32LF510U-ZB, 32LF550U-ZA, 32LF551C-ZA, 32LF560U-ZB, 32LF560V-ZB, 32LF5610-ZF, 32LF561V-ZF, 32LF562U-ZC, 32LF562V-ZC, 32LF564U-ZH, 32LF564V-ZH, 32LF620U-ZB, 40LF570V-ZA, 42LF550V-ZA, 42LF551C-ZA, 42LF560V-ZB, 42LF5610-ZF, 42LF561V-ZF, 42LF562V-ZC, 42LF564V-ZH, 42LF620V-ZB, 43LF5100-ZA, 43LF510V-ZA, 43LF5400-ZB, 43LF540V-ZB, 43LF570V-ZA, 49LF5100-ZA, 49LF510V-ZA, 49LF5400-ZB, 49LF540V-ZB, 49LF550V-ZA, 49LF551C-ZA, 49LF620V-ZB, 50LF5610-ZF, 50LF561V-ZF, 55LF5610-ZF, 55LF561V-ZF.

You can download the files from the manufacturer's website for the 32LF510B model.

LG 32LF551C TV with LCD NC320DXN VSBP8, 32" (81 cm) diagonal in 16:9 aspect ratio. The LCD panel implements the principle of direct backlighting of the display with the rear arrangement of LEDs - Direct LED.
NC320DXN matrix and MainBoard software EAX66203805 provide high quality HD viewing at 1366x768 pixels in 720p (HD Ready) resolution. Input analog video signal is decoded in PAL, SECAM, NTSC systems. Graphic processing of a digital signal is done in 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, WMA, MPEG4, DivX, MKV, JPEG.
The speaker system sound power of 10W (2x5W) is provided by two speakers. NICAM STEREO audio processing system is used.
Communication with other devices via an external interface is supported by standard inputs and outputs: antenna input (RF), AV, component, HDMI x2, USB. A VGA (D-Sub 15) connector is provided to connect a computer or laptop to this TV model. This interface supports standard resolutions: 640x480, 800x600, 1024x768, 1360x768. The digital tuner is capable of receiving TV channels in DVB-T, DVB-T2, DVB-C standards.

The TV set has the EAX66171501 power supply.

Dimensions: C stand 1122x712x237 mm, without stand 1122x660x55 mm.

Warning. The NC320DXN is an expensive and fragile part of your LG 32LF551C LED TV.
Do not allow any kind of impact on the glass and pressure on the screen surface to avoid damaging the LED panel!
It is also not safe to get liquid on the screen. Sometimes one drop is enough if it drips down the glass onto the cables and the TV becomes unrepairable.

REPAIRING / SERVICING TV LG 24LH480U

 Technical description and composition of LG 24LH480U TV, type of panel and modules used. Module composition.
Composition
Specifications
LG 24LH480U
Smart TV 24LH480U | Year of manufacture: 2016
Screen diagonal: 24" (61 cm)
Screen format: 16:9
Resolution: 1366x768
Frequency refresh rate:     50Hz
LED backlight: yes, Edge LED
Smart: yes. Wi-Fi support: yes
Support HD: 720p HD
Progressive scan: Yes
Digital tuner: DVB-T, DVB-T2, DVB-C
Teletext: Yes
Multimedia: MP3, MPEG4, JPEG
Sound stereo: there is
Sound Power: 10W (2x5W)
Acoustics: two speakers
Interface: HDMI x2, USB x2, Ethernet (RJ-45), Wi-Fi
Dimensions: With stand 556x388x130mm
Without stand 556x345x53mm
Find out more...
LG 24LH480U

LG LED
Model: 24LH480U - PZ

Chassis/Version: LU52A

Panel: V236BJ1-LE2

LED backlight: 6202B0005S000

LED driver (backlight): integrated into MainBoard

PWM LED driver: DT1641AS

MOSFET LED driver: TO-252

Power Supply (PSU): 19v Adapter

MainBoard: EAX66586404 (1.0) . EBR82930403

IC MainBoard: CPU, eMMC, DRAM, AUDIO, DC/DC

MainBoard: TDJM-G301D
General advice about LCD LED TV repair
Possible flaws

- LG 24LH480U does not turn on or shows no signs of working at all. Does not blink on indicators and does not respond to control buttons.

In some of these cases the main switching power supply - the Adapter module - is defective.
The TV is equipped with an external 19v Adapter type power supply. Owners of the TV can check them by replacing them and buy them in stores, but the ability to open and fix typical defects usually does not create difficulties for the master. Then you should measure its output voltages and in case of their full or partial absence you should check the serviceability of the power switches and rectifier diodes of converters for possible short circuits.
At breakdown of semiconductors in the secondary circuits of any converter, as a rule, it can work in the emergency short-circuit mode without output voltages, and at short circuit in the elements of the primary circuit the mains fuse and more rarely the current sensor at the source of the key most often break down at once.
Mos-Fet power switches used in switched-mode power supplies sometimes fail due to the failure of some other element that can take it out of key mode, or cause the switch to exceed its maximum allowable parameters. These can be the elements that feed the PWM controller, the frequency-retaining or damping circuits, or the negative feedback elements in the stabilization circuit. PWM controllers, if there is no visible damage or outright short circuits between pins, are checked by replacing with new or known good ones.

If the LG 24LH480U has no picture but has sound, often the V236BJ1-LE2 display backlight is just not working. Moreover, in LED TVs usually fail the LEDs inside the panel, less often the LED-driver.
In such cases you can see faintly visible image when external light hits the screen.

To replace the LEDs requires disassembly of the LCD panel V236BJ1-LE2 - a process that requires a master of experience and expertise. We do not recommend to perform such works by yourself to owners of TV sets and craftsmen who have no experience in LCD panel repair

If there is no image, but backlighting works - the screen becomes slightly lighter when the TV is switched on, and in the open TV you can see the light through the holes in the body of the panel.
In this case the panel may be defective - damage to the strips, cables, for example, as a consequence of moisture after an unsuccessful washing of the screen, the T-CON board (Timing Controller) may be defective. But quite often the MainBoard EAX66586404 is defective, and software failure is also possible.
Then first it is necessary to check the panel supply voltage, fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within normal limits, it is necessary to trace by oscilloscope the LVDS signals from MainBoard EAX66586404, as well as synchronizing signals to the driver stubs.

Filled or unsuccessfully washed LED TV screens can be restored in about half of the cases, usually, if there was not significant damage in the cables and panel bars.

- No picture, sound is present and all other TV functions work. When turning on, the picture can sometimes appear for a second.

As a rule, in this case it turns out that the LED panel backlight is defective. Usually the cause of the fault is a breakage in the LEDs, or in the connectors of the LED strips, but sometimes the LED-driver is also faulty.
It should be remembered that to determine the breakage in the lines of LEDs without disassembling the panel, with a tester or multimeter is not possible without an additional device, such as a current source. To open all the PN-junctions connected in series at once a voltage of several tens of volts may be required. Then you have to open the panel and check each LED separately with a multimeter. If the possibilities of your multimeter do not allow to open the LED in the forward direction or twin LEd's are used, then the PN junction of the faulty stabilizer can indirectly serve as an indication of serviceability. If the LED is faulty, the PN junction of the stabilizer will either be open or shorted.

READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.

- Front panel LED is blinking, TV set does not turn on, remote control is unresponsive.

Repair or diagnosis of the motherboard EAX66586404 should begin with checking the stabilizers and power converters needed to power the chips and matrix. If necessary, software (software) should be updated or replaced. Sometimes elements of MainBoard - CPU, eMMC, DRAM, AUDIO, DC/DC need checking or replacement (if necessary). If a BGA processor is used, its failure is usually detected by local heating.

Before replacing the TDJM-G301D tuner if you cannot tune to the TV channels, make sure the supply voltages are present and measure at the respective pins of the tuner and check the software for correctness. The tuner-to-processor communication pulses can be checked with an oscilloscope

To the users and owners of TV sets it is necessary to remember that attempting to repair LG 24LH480U TV set itself without the relevant qualification and necessary experience, can lead to serious negative consequences!

DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    LG 24LH480U Chassis LU52A.

 Refinement after the repair of the backlight. EAX66586404, DT1641AS. Information from the master.

Decreased backlight current from 180 mA to 120 mA - increased the rating of one of the resistors (R1025) from pin 7 of ISET chip DT1641AS from 24 to 43 kOhm on board EAX66586404.
More on MainBoard Repair

The MainBoard EAX66586404 is shown in the figure below:

EAX66586404.

Main features of the LG 24LH480U:

A matrix (LED panel) V236BJ1-LE2 is installed.
To power the LED backlight is used converter, combined with the main board EAX66586404, controlled by PWM controller DT1641AS. As the power elements of the LED-driver switches of TO-252 type are used.
To power all the internal components of LG 24LH480U TV set an external power supply of Adapter 19v type is used.
MainBoard - the main board (motherboard) is EAX66586404 module using CPU, eMMC, DRAM, AUDIO, DC/DC and other chips.
The TDJM-G301D tuner provides TV program reception and channel tuning.

More technical information about the panel:
Brand : CHIMEI INNOLUX
Model : V236BJ1-LE2
Type : A-Si TFT-LCD, Panel
Diagonal size : 23.6 inch
Resolution : 1366x768, WXGA
Display Mode : Super MVA, Normally Black, Transmissive
Active Area : 521.471x293.184 mm
Surface : Antiglare (Haze 1%), Hard coating (3H)
Brightness : 250 cd/m²
Contrast Ratio : 3000:1
Display Colors : 16.7M (8-bit), CIE1931 72%
Response Time : 8.5 (G to G)
Frequency : 60Hz
Lamp Type : WLED Without Driver
Signal Interface : LVDS (1 ch, 8-bit), 30 pins
Voltage : 12.0V

LG 24LH480U TV with V236BJ1-LE2 LCD display, measuring 24" (61 cm) diagonally in 16:9 aspect ratio. This model uses a panel with an end arrangement of LEDs in the display backlight - Edge LED.
V236BJ1-LE2 matrix and MainBoard software EAX66586404 provide high quality HD viewing at a resolution of 1366x768 pixels in 720p (HD Ready).
The 24LH480U features SMART software, built-in applications and Internet connectivity. You can connect to the network using Wi-Fi wireless connectivity. Supported media formats: MP3, MPEG4, JPEG.
The speaker system has a sound power of 10 W (2x5 W) provided by two speakers. It uses NICAM stereo sound processing and Sound Surround surround function.
Communication with other devices via an external interface is supported by standard input and output connectors: antenna input (RF), HDMI x2, USB x2, Ethernet (RJ-45), Wi-Fi. The digital tuner is capable of receiving TV channels in the DVB-T, DVB-T2, DVB-C standards.

The TV uses an external power supply Adapter 19v.

Dimensions: C stand 556x388x130 mm, without stand 556x345x53 mm.

Warning. The V236BJ1-LE2 LED TV panel of LG 24LH480U is an expensive and unreliable part of the TV.
Avoid any kind of impact on the glass and pressure on the screen surface to avoid damaging the LED panel!
Also it is not safe to get liquid on the screen. Sometimes one drop is enough if it drips down the glass onto the cables and the TV becomes unrepairable.

REPAIRING / SERVICING TV THOMSON T43D18SFS-01B

Technical description and composition of the THOMSON T43D18SFS-01B TV, panel type and modules used. The composition of the modules.

THOMSON LED
Model: T43D18SFS-01B

Chassis / Version: MT56T2

Panel: LVF430LGD0 E2 V52 A430LD4DUY-40

LED backlight: 3 strips of 8 led 3V

LED driver (backlight): integrated into PSU

PWM LED driver: MP3398A

MOSFET LED driver: PC015BD

Power Supply (PSU): SHG4301A-101H

PWM Power: OB5269CPAB MP1582

MOSFET Power: MDF10N60B

MainBoard: 40-MT56T2-MAF2HG

IC MainBoard: CPU, eMMC, DRAM, AUDIO, DC / DC

Tuner: ST55WM-2-E9

Specifications T43D18SFS-01B
THOMSON T43D18SFS-01B
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions

- The THOMSON T43D18SFS-01B TV does not turn on and does not show any signs of turning on, does not respond to the control buttons and the remote control.

In such cases, you should start looking for a fault in the SHG4301A-101H power supply circuits. It is necessary to measure its output voltages, and if they are absent (full or partial), the serviceability of the power switches (MDF10N60B) of the converters and rectifier diodes should be checked for a possible short circuit.
In case of breakdowns in the secondary circuits, the converter, as a rule, can operate in an emergency mode in a short-circuit mode, and in case of a short circuit in the power elements of the primary circuit, the mains fuse is usually cut off.
Breakdown of Mos-Fet keys used in switching power supplies is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency setting or damper circuits, as well as in negative feedback stabilization. PWM microcircuits (PWM) OB5269CPA and MP1582 are usually checked by replacing them with new ones, or knowingly working properly.

- There is no picture, but there is sound, it reacts to the remote control. Or the image appears when turned on and immediately disappears

As a rule, in such cases there is no display backlight. Usually the cause of the malfunction is in the breakage of the LEDs, or in the connectors of the LED strips 3 strips of 8 led 3V each, but sometimes the LED driver is also faulty.
To identify an open circuit in the LED lines without disassembling the panel, a current source is required. It is impossible to open the junctions connected in series with a simple multimeter; a voltage of several tens of volts is required.



If THOMSON T43D18SFS-01B has no image, but there is sound, often the display backlight LVF430LGD0 E2 V52 A430LD4DUY-40 simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.

Replacing the LEDs requires disassembling the LVF430LGD0 LCD panel - a process that requires experience and qualifications from the master. We do not recommend doing such work on your own to the owners of TVs and craftsmen who do not have experience in repairing LCD panels

If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light is visible through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But the main board MainBoard 40-MT56T2-MAF2HG often turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, the fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within normal limits, it is necessary to trace the passage of LVDS signals from the MainBoard 40-MT56T2-MAF2HG with an oscilloscope, as well as synchronizing signals to the loops with drivers.

Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.

- The indicator blinks or is on constantly, the TV does not turn on, does not respond to the remote control.

Repair or diagnostics of the 40-MT56T2-MAF2HG motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). In cases of complex MB (SSB) repairs and with the necessary skills and equipment, it may sometimes be necessary to replace its CPU, eMMC, DRAM, AUDIO, DC / DC chips and other possible faulty components. Malfunctions associated with the use of BGA soldering technologies are usually easily diagnosed by the warm-up method.

If there is no reception of TV channels, but the TV is working properly from external devices, first of all, you need to check the supply voltage of the ST55WM-2-E9 tuner and update the software. I2C communication pulses must be monitored with an oscilloscope.

Attention to TV owners! Attempts to repair THOMSON T43D18SFS-01B on your own are not recommended by the manufacturer and can lead to serious negative consequences! 

DOWNLOAD SHG4301A-101H DLBB449 Power supply diagram. ---->   SHG4301A-101H DLBB449 Power supply.
 

Current limitation. MP3398A. General recommendations:

To reduce the backlight current in LED drivers with an MP3398A controller, you should proportionally increase the total resistance of the resistors relative to the case at the ISET pin of the MP3398A controller. ISET (current setting) - pin 6 in SOIC-16 package (8 in SOIC-20 package).
The formula for the inverse proportion of the backlight current in milliamperes and the resistance Rset in kilo-ohms:
I [mA] = 988 / Rset [kOhm].

DOWNLOAD MP3398A  DIAGRAM  /  MANUAL   ------------------>   MP3398A.


The appearance of the MainBoard 40-MT56T2-MAF2HG is shown in the figure below:

40-MT56T2-MAF2HG

External view of the power supply

The main features of the THOMSON T43D18SFS-01B device:

Installed matrix (LED-panel) LVF430LGD0 E2 V52 A430LD4DUY-40.
A converter combined with a power supply is used to power the backlight LEDs and is controlled by the MP3398A PWM controller. The keys of the PC015BD type are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the THOMSON T43D18SFS-01B TV is carried out by the SHG4301A-101H power module, or its analogs using OB5269CPAb MP1582 microcircuits and MDF10N60B power switches.
MainBoard - the main board (motherboard) is a 40-MT56T2-MAF2HG module, using CPU, eMMC, DRAM, AUDIO, DC / DC chips and others.
The ST55WM-2-E9 tuner provides reception of television programs and tuning to channels.

LED TV THOMSON T43D18SFS-01B with LCD LVF430LGD0, measuring 43 "(109 cm) diagonally 16: 9. The declared brightness of the screen of 220 cd / m2 is provided by modern LED backlighting. The ratio of maximum brightness to minimum (contrast) is not less than 1200: 1. The LCD panel uses a direct backlighting with a rear-mounted LED - Direct LED.
The LVF430LGD0 matrix and MainBoard 40-MT56T2-MAF2HG software realize high quality HD images at a resolution of 1920x1080 pixels in 1080p (Full HD) graphics.
The T43D18SFS-01B TV is equipped with SMART software, built-in applications and the ability to work on the Internet. Internet connection can be made via Wi-Fi wireless connection. Supported media formats: MP3, MPEG4, JPEG.
Speaker power 16 W (2x8 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), SCART, HDMI x3, MHL, USB x2, Ethernet (RJ-45), Wi-Fi. A headphone jack is provided. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.

The power supply unit is SHG4301A-101H.

Dimensions: with stand 977x624x221 mm, without stand 977x588x91 mm.

TV weight: 7.5 kg.

Attention! The LVF430LGD0 E2 V52 A430LD4DUY-40 panel of the THOMSON T43D18SFS-01B LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.

Once again, I remind THOSE IDIOTS users WANNABE IMPROVISED  INTERNET BULLSHIT FOOLS GUYS  and TV owners:

Self-repair attempts can have serious negative consequences, up to complete non-repairability.  

REPAIRING / SERVICING TV LG 42LY750H

 Technical description and composition of the LG 42LY750H TV, panel type and modules used. The composition of the modules.

LG LED
Model: 42LY750H

Chassis / Version: LD4FC

Panel: LC420DUH (FG) (A1)

LED driver (backlight): integrated into PSU

PWM LED driver: BD9486F

MOSFET LED driver: 4NF20, MDD3752

Power Supply (PSU): EAX65423701 (2.0) LGP3942-14PL1

PWM Power: MAP8800 (PFC), FA6A01N (PWM resonant), NR134S

MOSFET Power: TK7P60W, 60R360P

MainBoard: EAX65384003 (1.2) EBR78515108

IC MainBoard: CPU: LG1311, DRAM: H5TQ4G63AFR-PBC, EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR

Tuner: TDJM-G101D

Specifications 42LY750H
LG 42LY750H
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions

- LG 42LY750H does not turn on and does not show any signs of operation at all. Does not blink indicators and does not respond to control buttons.

In such cases, the power supply EAX65423701 usually fails. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches (TK7P60W, 60R360P) and rectifier diodes for possible partial or complete breakdown.
In case of breakdowns in the secondary circuits, the converter, as a rule, can operate in an emergency mode in a short-circuit mode, and in case of a short circuit in the power elements of the primary circuit, the mains fuse is usually cut off.
Breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM controllers (PWM) MAP8800 (PFC), FA6A01N (PWM resonant), NR134S, if they do not have visible damage to the case and an open short circuit between the pins, are usually checked by replacing.

- There is no picture, but there is sound, it reacts to the remote control. Or the image appears when turned on and immediately disappears

A malfunction is usually in these cases most likely in the backlight units of the display matrix. Usually the cause of the malfunction is in the breakage of the LEDs, or in the connectors of the LED strips, but sometimes the LED driver is also faulty.
When diagnosing, it must be borne in mind that it is impossible to check for an open circuit in the LED strips circuit without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally a current source. By opening the panel, you can check each LED separately. Typically, Chinese multimeters will lightly light one 3-volt LED when the probes are connected to it in the forward direction. For dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of the LED health. In the event of a malfunction of the LED, its zener diode will either be cut off or pierced in the K / Z.

If the LG 42LY750H has no picture, but there is sound, the LCD backlight LC420DUH (FG) (A1) often simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.

Replacing the LEDs requires disassembling the LC420DUH LCD panel, a process that requires experience and qualifications from the technician. We do not recommend doing such work on your own to the owners of TVs and craftsmen who do not have experience in repairing LCD panels

If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light is visible through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But often the main board MainBoard EAX65384003 turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, the fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within the normal range, it is necessary to use an oscilloscope to trace the passage of LVDS signals from the MainBoard EAX65384003, as well as synchronization signals to the loops with drivers.

Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.

- The TV does not turn on, the indicator signals the standby or operating mode, or blinks.

Repair or diagnostics of the EAX65384003 motherboard should begin with checking the stabilizers and power converters required to power the microcircuits and matrix. If necessary, you should update or replace the software (software). In cases of complex MB (SSB) repairs and with the necessary skills and equipment, it may sometimes be necessary to replace its chips CPU: LG1311, DRAM: H5TQ4G63AFR-PBC, EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR and other possible faulty components. Malfunctions associated with the use of BGA soldering technologies are usually easily diagnosed by the warm-up method.

The malfunction of the TDJM-G101D tuner is established after checking the software and all supply voltages at its terminals. The tuner data exchange with the processor via the I2C bus can be monitored with an oscilloscope.

I remind users again! Attempts to repair the LG 42LY750H TV without proper qualifications and the necessary experience can lead to its complete non-repairability!

DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------> CHASSIS : LD4FC   FOR MODELS:  42LY750H, 42LY750H-ZA, 42LW750H, 42LW750H-ZA.

The appearance of the MainBoard EAX65384003 is shown in the figure below:

EAX65384003

EAX65384003 can be used in TVs:

LG 47LB650V ZE (Panel LC470DUH (FG) (P2)), LG 42LB631V ZL (Panel LC420DUH (FG) (A1)), LG 39LB650V (Panel T390HVJ01.2), LG 55LB673V ZB (Panel LC550DUH (PG)(F1)), LG 47LB677V (Panel LC470DUH (FG)(F1)), LG 42LB673V (Panel LC420DUH (PG)(F1)), LG 47LB673V (Panel LC470DUH (PG)(F1)), LG 32LB652V 32LB652V-ZA.BRUWLDU (Panel LC320DUH (FG)(P2)), LG 50LB653V (Panel LC500DUH (FG)(P1)), LG 42LB652V 42LB652V-ZA.BRUWLJU (Panel LC420DUH (FG)(P2)), LG 55LB720V 55LB720V-ZG.BRUWLJU (Panel LC550DUH (PG)(F1)).


External view of the power supply

Main features of the LG 42LY750H device:

Installed matrix (LED panel) LC420DUH (FG) (A1).
A converter combined with a power supply is used to power the backlight LEDs, and is controlled by a BD9486F PWM controller. The keys of the 4NF20, MDD3752 types are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the LG 42LY750H TV is carried out by the EAX65423701 power module, or its analogs using MAP8800 (PFC), FA6A01N (PWM resonant), NR134S microcircuits and TK7P60W, 60R360P power switches.
MainBoard - the main board (motherboard) is an EAX65384003 module using CPU: LG1311, DRAM: H5TQ4G63AFR-PBC, EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR and others.
Tuner TDJM-G101D provides reception of television programs and tuning to channels.

Additional technical information about the panel:
Brand: LG Display
Model: LC420DUH-FGA1
Type: a-Si TFT-LCD, Panel
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: IPS, Normally Black, Transmissive
Active Area: 927.94x521.96 mm
Surface: Antiglare (Haze 1%), Hard coating (3H)
Brightness: 300 cd / m²
Contrast Ratio: 1200: 1
Display Colors: 16.7M (8-bit), CIE1931 68%
Response Time: 6/8 (Tr / Td)
Frequency: 120Hz
Lamp Type: WLED Without Driver
Signal Interface: EPI, 100 pins
Voltage: 12.0V

Technical specifications for this LG 42LY750H ------------------> LG 42LY750H TV with LCD display LC420DUH (FG) (A1), 42 "(107 cm) diagonal, 16: 9. 

The required screen brightness of 300 cd / m² is provided by LED backlighting. Contrast as the ratio of maximum brightness to minimum brightness , is 1200: 1. The display technology of this model is implemented with LED backlighting.
The LC420DUH sensor and MainBoard EAX65384003 software provide viewing of broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphics resolution at 1080p (Full HD).
The 42LY750H is equipped with SMART software, built-in applications and Internet connectivity. The connection to the network can be carried out via Wi-Fi wireless connection. The input analog video signal is decoded in PAL, SECAM, NTSC systems. Graphic processing of a digital signal is performed in the 480i, 480p, 576i, 576p, 720p, 1080i, 1080p standards. Supported media file formats: MP3, JPEG.
Speaker power 20 W (2x10 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
Communication with other devices via an external interface is supported by standard input and output connectors: antenna input (RF), SCART, RGB, HDMI, USB x2, RS-232, Ethernet (RJ-45), Wi-Fi, WiDi, Miracast. A headphone jack is provided. A VGA (D-Sub 15) connector is provided to connect a computer or laptop to this TV model. This interface supports standard resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080. The digital tuner is capable of receiving TV channels in DVB-T, DVB-C standards.

The TV uses an EAX65423701 power supply.

Dimensions: With stand 849x561x236 mm, Without stand 849x512x79 mm.

TV weight: 9.5 kg.

Attention! The LC420DUH panel of the LG 42LY750H LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.
Once again, we remind users and TV owners.
Self-repair attempts can have serious negative consequences, up to complete non-repairability.

REPAIRING / SERVICING TV LG 50LB675V

Technical description and composition of the LG 50LB675V TV, panel type and modules used. The composition of the modules.

LG LED
Model: 50LB675V

Chassis / Version: LD42B

Panel: LC500DUH (PG) (F2)

LED driver (backlight): integrated into PSU

PWM LED driver: iW7025-00

Power Supply (PSU): EAX65424001 (2.4) LGP4750-14LPB

PWM Power: MAP8800 (PFC), CP1034DG, ICE3BR4765JZ

MOSFET Power: 13N60M2

MainBoard: EAX65384004 (1.4) EBT63301001

IC MainBoard: CPU: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR

Tuner: TDJM-G101D

Specifications 50LB675V
LG 50LB675V
General recommendations for TV LCD LED repair
Possible malfunctions

- The LG 50LB675V TV does not turn on, does not respond to the remote control and control panel buttons, the indicators do not light up or flash.

Usually with similar manifestations, the defect is caused by faulty elements in the main power supply module EAX65424001. It is necessary to measure its secondary output voltages, and if they are absent, check the power switches (13N60M2) and rectifier diodes in the converters for a short circuit.
In case of any breakdowns in the secondary circuits, the converter can operate in an emergency mode of a short circuit, and with a short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key is often cut off.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements, which can disable it in key mode, or provoke an excess of the maximum current or voltage values. These can be circuits supplying the PWM controller, damper or frequency setting circuits, or OOS (negative feedback) elements in the stabilization circuit. PWM controllers (PWM) MAP8800 (PFC), CP1034DG, ICE3BR4765JZ, in the absence of external damage and short circuit between the terminals, are checked by replacing them with known good ones.

- No picture, sound, all other TV functions are working. When turned on, the image may sometimes appear for a second.

As a rule, in such cases there is no display backlight. The reason may be in the breakage of the backlight LEDs, in the stabilization of their power supply, or in the violation of the contact connections of the strings connectors.
When diagnosing, it must be borne in mind that it is impossible to check for an open circuit in the LED strips circuit without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally a current source. By opening the panel, you can check each LED separately. Typically, Chinese multimeters will lightly light one 3-volt LED when the probes are connected to it in the forward direction. For dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of the LED health. In the event of a malfunction of the LED, its zener diode will either be cut off or pierced in the K / Z.

If the LG 50LB675V does not have a picture, but there is sound, often the LCD backlight LC500DUH (PG) (F2) simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.

Replacing the LEDs requires disassembling the LC500DUH LCD panel - a process that requires experience and qualifications from the technician. We do not recommend doing such work on your own to the owners of TVs and craftsmen who do not have experience in repairing LCD panels

If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light is visible through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But often the main board MainBoard EAX65384004 turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, the fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within normal limits, it is necessary to trace the passage of LVDS signals from the MainBoard EAX65384004 with an oscilloscope, as well as synchronization signals to the loops with drivers.

Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.

- The TV does not go into operation, does not respond to the remote control. The indicator on the front panel is on or blinking.

Repair or diagnostics of the EAX65384004 motherboard should begin with checking the stabilizers and power converters required to power the microcircuits and matrix. If necessary, you should update or replace the software (software). Complicated repair of MB (SSB) board is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the CPU elements: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR. BGA chip faults are usually easy to detect by warm-up.


Before replacing the TDJM-G101D tuner, if there is no tuning to the channels, you must first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus

Attention! Users and owners of 50LB675V TVs who do not have the appropriate qualifications, knowledge and experience are strongly discouraged from attempting to repair themselves in order to avoid negative consequences that may lead to complete non-repairability of the device.

DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>  CHASSIS : LD42B   FOR MODELS:    50LB670V, 50LB671V, 50LB675V, 50LB677V.

Additional MainBoard Repair

The appearance of the MainBoard EAX65384004 is shown in the figure below:

EAX65384004

EAX65384004 can be used in TVs:

LG 32LB650V ZE (Panel LC320DUH (FG)(P2)), LG 47LB650V ZE (Panel LC470DUH (FG) (P2)), LG 42LB650V (Panel LC420DUH (FG)(P2)), LG 42LB671V ZF (Panel LC420DUH (PG) (F1)), LG 47LB671V (Panel LC470DUH (PG)(F1)), LG 42LB653V ZK (Panel LC420DUH (FG)(P1)), LG 42LB720V (Panel LC420DUH (PG)(F1)), LG 42LB658V (Panel LC420DUH (FG)(P2)), LG 47LB677V (Panel LC470DUH (FG)(F1)), LG 42LB679V (Panel LC420DUH (PG)(F1)), LG 47LB653V (Panel LC470DUH (FG)(P1)), LG 32LB653V (Panel LC320DUH( FG)(P1)), LG 42LB690V (Panel LC420DUH (PG)(F1)), LG 55LB630V (Panel LC550DUH).


External view of the power supply

Main features of the LG 50LB675V device:

Installed matrix (LED-panel) LC500DUH (PG) (F2).
A converter combined with a power supply is used to power the backlight LEDs and is controlled by the iW7025-00 PWM controller.
The formation of the necessary supply voltages for all nodes of the LG 50LB675V TV is carried out by the EAX65424001 power supply module, or its analogs using MAP8800 (PFC), CP1034DG, ICE3BR4765JZ microcircuits and 13N60M2 power switches.
MainBoard - the main board (motherboard) is an EAX65384004 module, using CPU chips: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR and others.
Tuner TDJM-G101D provides reception of television programs and tuning to channels.


Instructions and updates

There are files to download for the 49LB870V model from the manufacturer:

Files with updates and instructions:
File Description File Name Type Date Size
SW File (Version 05.05.70). Update instructions TV_Software_Update_Guide_v3.pdf PDF 18.07.2019 2014K
SW File (Version 05.05.70). Firmware (USB) Software_File (Version_05.05.70) .zip ZIP 18.07.2019 674112K

Compatible with:
 32LB650V-ZE, 32LB650V-ZN, 32LB652V-ZA, 32LB653V-ZK, 32LB656V-ZN, 39LB650V-ZE, 39LB650V-ZN, 42LB630V-ZA, 42LB631V-ZL, 42LB639V-ZU, 42LB650V-ZE, 42LB650V-ZN, 42LB652V-ZA, 42LB653V-ZK, 42LB656V-ZN, 42LB658V-ZE, 42LB670V-ZA, 42LB671V-ZB, 42LB671V-ZF, 42LB673V-ZB, 42LB674V-ZB, 42LB676V-ZA, 42LB677V-ZC, 42LB678V-ZF, 42LB679V-ZF, 42LB679V-ZH, 42LB680V-ZD, 42LB689V-ZF, 42LB690V-ZC, 42LB700V-ZG, 42LB720V-ZG, 42LB730V-ZD, 42LB731V-ZE, 47LB630V-ZA, 47LB631V-ZL, 47LB650V-ZE, 47LB650V-ZN, 47LB652V-ZA, 47LB653V-ZK, 47LB656V-ZN, 47LB670V-ZA, 47LB671V-ZB, 47LB671V-ZF, 47LB673V-ZB, 47LB674V-ZB, 47LB676V-ZA, 47LB677V-ZC, 47LB678V-ZF, 47LB679V-ZF, 47LB679V-ZH, 47LB680V-ZD, 47LB690V-ZC, 47LB700V-ZG, 47LB720V-ZG, 47LB730V-ZD, 47LB731V-ZE, 49JL9000-ZA, 49LB860V-ZB, 49LB870V-ZA, 50LB650V-ZE, 50LB650V-ZN, 50LB653V-ZK, 50LB670V-ZA, 50LB671V-ZB, 50LB674V-ZB, 50LB675V-ZA, 50LB676V-ZA, 50LB677V-ZC, 55JL9000-ZA, 55LB630V-ZA, 55LB631V-ZL, 55LB650V-ZN, 55LB652V-ZA, 55LB653V-ZK, 55LB656V-ZN, 55LB670V-ZA, 55LB671V-ZB, 55LB671V-ZF, 55LB673V-ZB, 55LB674V-ZB, 55LB675V-ZA, 55LB676V-ZA, 55LB678V-ZF, 55LB679V-ZF, 55LB680V-ZD, 55LB690V-ZC, 55LB700V-ZG, 55LB720V-ZG, 55LB730V-ZD, 55LB731V-ZE, 55LB860V-ZB, 55LB870V-ZA, 60JL9000-ZA, 60LB650V-ZN, 60LB680V-ZD, 60LB720V-ZG, 60LB730V-ZE, 60LB860V-ZB, 60LB870V-ZA, 65LB680V-ZD, 65LB730V-ZE, 70LB650V-ZA.
 
 
User Manuals and Instructions:
File type File name Language Date Size
User manual MFL68027016_05_RS.pdf English 01/20/2015 82,236K
Quick Start Guide WebOS_L_EU_13.zip English, Estonian, Latvian, Lettish, Lithuanian, Russian 03/10/2015 13,751K
Quick setup instructions MBM63817892_rev02_ENG.pdf English 09/11/2015 6,311K

Files can be downloaded from the manufacturer's website for the 49LB870V model.

 

 

TV LG 50LB675V with LCD display LC500DUH (PG) (F2), diagonal size 50 "(127 cm) 16: 9 format. The LCD-panel implements the principle of direct display backlighting with rear-mounted LEDs - Direct LED.
There is support for 3D images using passive polarization technology.
The LC500DUH sensor and MainBoard EAX65384004 software provide viewing of broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphics resolution at 1080p (Full HD).
TV model 50LB675V has built-in SMART software and webOS operating system installed. The connection to the network can be carried out via Wi-Fi wireless connection. The input analog video signal is decoded in PAL, SECAM, NTSC systems. Graphic processing of a digital signal is performed in the 480i, 480p, 576i, 576p, 720p, 1080i, 1080p standards. Supported media file formats: MP3, WMA, MPEG4, DivX, MKV, JPEG.
Sound system power of 24 W is provided by 3 speakers. The NICAM stereo audio processing system and the Sound Surround function are used.
Communication with other devices via an external interface is supported by standard input and output connectors: antenna input (RF), AV, audio x2, component, SCART, RGB, HDMI x3, MHL, USB x3, Ethernet (RJ-45), Wi-Fi 802.11 n, WiDi, Miracast. A headphone jack is provided. A VGA (D-Sub 15) connector is provided to connect a computer or laptop to this TV model. This interface supports standard resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080. The digital tuner is capable of receiving TV channels in the DVB-T, DVB-T2, DVB-C, DVB-S2 standards.

The TV uses an EAX65424001 power supply.

Dimensions: With stand 1116x705x247 mm, Without stand 1116x653x55 mm.

Attention! Panel LC500DUH LED-TV LG 50LB675V is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable. 

REPAIRING / SERVICING TV LG 22LN457U

 
Technical description and composition of the LG 22LN457U TV, panel type and modules used. The composition of the modules.

LG LED
Model: 22LN457U

Chassis / Version: LD31T

Panel: LC216EXN (SF) (A1)

LED backlight: 6916L-1237A 21.6 V13 EDGE REV0.1 2 6920L-0001C

T-CON: 6870S-1619B LC216EXN_SFA1_Source_Ver 0.7 H / F; TL2345ML, TPS65170

LED driver (backlight): integrated into T-CON

PWM LED driver: BD9472EFV SOP24

MOSFET LED driver: RSD050N10

Power Supply (PSU): Adapter 19V 2.1A

MainBoard: EAX65077504 (1.0)

IC MainBoard: CPU: LGE2121-MS, SPI Flash: MX25L8005, DRAM: H5TQ1G63EFR, Audio: TNP7513

Tuner: TDSQ-G601D (B)

Specifications 22LN457U
LG 22LN457U
General recommendations for TV LCD LED repair
Possible malfunctions

- The LG 22LN457U TV does not turn on, does not respond to the remote control and control panel buttons, does not light or blink indicators.

Most often, with similar manifestations, the main adapter power module turns out to be faulty.
The power source in this model is an external Adapter 19V 2.1A, usually the owners of TVs can purchase them on their own, and their repair may be impractical. But sometimes it is not difficult to open the unit and eliminate simple typical defects characteristic of most SMPS. It is necessary to measure its secondary output voltages, and if they are absent, check the power switches and rectifier diodes in the converters for a short circuit.
In case of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and with a short circuit in the power elements of the primary circuit, the mains fuse and / or the current sensor in the source of the key usually breaks off.
Mos-Fet power switches used in switching power supplies sometimes fail due to a malfunction of any other elements that can disable it in the key mode, or create an excess of the maximum permissible key parameters. These can be elements supplying a PWM regulator, frequency setting or damper circuits, or elements of negative feedback in the stabilization circuit. PWM controllers, in the absence of visible damage or outright short circuits between the terminals, are checked by replacing them with new ones, or knowingly working properly.

- There is no image, there is sound, it reacts to the remote control. Or, immediately after switching on for a second, the image may appear and immediately disappear.

In such cases, the most likely malfunction of the LED panel backlighting elements. Most often the reason for this is a break in the LEDs, or poor contact in the connectors of the brackets, less often the LED driver may be faulty.
When trying to detect a break in the LED lines, it should be borne in mind that it is difficult to do this without disassembling the panel. For example, a current source is required to open PN junctions connected in series.

If the LG 22LN457U has no picture, but there is sound, often the LCD backlight LC216EXN (SF) (A1) simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.

Replacing the LEDs requires disassembling the LC216EXN LCD panel, a process that requires experience and qualifications from the technician. We do not recommend doing such work on your own to the owners of TVs and craftsmen who do not have experience in repairing LCD panels

If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light is visible through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But the main board MainBoard EAX65077504 (1.0) often turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, the fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within normal limits, it is necessary to trace the passage of LVDS signals from MainBoard EAX65077504 (1.0) with an oscilloscope, as well as synchronizing signals to loops with drivers.

Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.


- The indicator blinks or is on constantly, the TV does not turn on, does not respond to the remote control.

Repair or diagnostics of the EAX65077504 motherboard should begin with checking the stabilizers and power converters required to power the microcircuits and matrix. If necessary, you should update or replace the software (software). In some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - CPU: LGE2121-MS, SPI Flash: MX25L8005, DRAM: H5TQ1G63EFR, Audio: TNP7513 with new or known good ones. In cases where BGA technologies are used, defects are usually localized by heating.

If there is no reception of television channels, but the TV is working properly from external devices, first of all, you need to check the supply voltage of the TDSQ-G601D tuner (B) and update the software. I2C communication pulses must be monitored with an oscilloscope.

Remember! Attempts to self-repair the LG 22LN457U TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!

DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>  Chassis: LC31A / LD31T   FOR MODELS:     22LN450U, 22LN457U Z*.

 

DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->  22LN457U

Driver current limitation. BD9472EFV LC216EXN_SFA1. 

 

General recommendations

To reduce the backlight current in LED drivers with a BD9472EFV controller on the T-CON board, you can increase the total resistance of the resistors from pin 23 (ISET) of the BD9472EFV to the case. The exact proportional relationship may not be observed, the values ​​should be selected empirically.

BD9472EFV LED-Driver, T-CON 6870S-1619B LC216EXN_SFA1:

In LED drivers with a BD9472EFV chip on the T-CON bar, you can increase the total resistance of the resistors from pin 23 (ISET) of the BD9472EFV to the case. The exact proportional relationship may not be observed, the values should be selected empirically.
The drawing was compiled by hand visually from the T-CON bar, there was no documentation for the BD9472EFV on the Internet.
For the LC216EXN (SF) (A1) panel and 6916L-1237A backlight bar, the current was initially 70 mA in each of the two channels at maximum (a few seconds after switching on without a signal).
After increasing one of the resistors from 91 kOhm to 160 kOhm, the current decreased to 50 mA.
Diodes of standard size 7020, double, but the transitions are connected in parallel inside, therefore - three-volt.
There are 28 LEDs on the bar - two channels of 14 each.

 

Additional MainBoard Repair

The appearance of the MainBoard EAX65077504 is shown in the figure below:

EAX65077504

EAX65077504 can be used in TVs:

LG 24MN33V PZ (Panel V236BJ1-LE1 Rev.C2), LG 22LN450U 22LN457U (Panel LC216EXN (SF)(A1)), LG 22LN548M (Panel LC216EXN (SF)(A1)).

Main features of the LG 22LN457U device:

Installed matrix (LED panel) LC216EXN (SF) (A1).
Matrix control uses the 6870S-1619B Timing Controller (T-CON).
An integrated LED driver is used to power the backlight LEDs, controlled by the BD9472EFV SOP24 PWM controller. RSD050N10 keys are used as power elements of the LED driver.
An external adapter 19V 2.1A is used to power all the internal components of the LG 22LN457U TV.
MainBoard - the main board (motherboard) is an EAX65077504 module using CPU chips: LGE2121-MS, SPI Flash: MX25L8005, DRAM: H5TQ1G63EFR, Audio: TNP7513 and others.
Tuner TDSQ-G601D (B) provides reception of TV programs and tuning to channels.

Additional technical information about the panel:
Brand: LG Display
Model: LC216EXN-SFA1
Type: a-Si TFT-LCD, Panel
Diagonal size: 21.6 inch
Resolution: 1366x768, WXGA
Display Mode: IPS, Normally Black, Transmissive
Active Area: 477.417x268.416 mm
Surface: Antiglare (Haze 1%), Hard coating (3H)
Brightness: 250 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit), CIE1931 68%
Response Time: 6 (G to G)
Frequency: 60Hz
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V



Instructions and updates

There are files to download for model 22LN457U from the manufacturer:

Files with updates and instructions:
File Description File Name Type Date Size
SW File (Version 03.10.13). Firmware (USB) Software_File (Version_03.10.13) .zip ZIP 30.11.2016 62777K
SW File (Version 03.10.13). Update instruction TV_Software_Update_Guide_v3.pdf PDF 30.11.2016 1938K
Compatible with 22LN450U-ZB, 22LN457U-ZI, 26LN450B-ZB, 26LN450U-ZB, 26LN457B-ZI, 26LN457U-ZI, 28LN450U-ZB, 28LN457U-ZI, 29LN450B-Z50N-29LN445
Software Upgrade Guide. Upgrade instructions Software_Upgrade_Guide (CIS) .pdf PDF 08/20/2013 743K

User Manuals and Instructions:
File type File name Language Date Size
User manual MFL67707907_ (1404) _04REV.pdf English, Russian 08/14/2014 56,952K
Quick Start Guide NC4_L_E_L05_140306_ENG.pdf English 03/07/2014 8,750K

The files can be downloaded from the manufacturer's website for the 22LN457U model.



LG 22LN457U TV with LCD display LC216EXN (SF) (A1), 22 "(56 cm) diagonal, 16: 9 format. This model uses a panel with edge LED backlighting - Edge LED.
The LC216EXN sensor and MainBoard EAX65077504 (1.0) software provide high quality HD viewing at a resolution of 1366x768 pixels in 720p (HD Ready). The input analog video signal is decoded in PAL, SECAM, NTSC systems. Graphic processing of a digital signal is performed in the 480i, 480p, 576i, 576p, 720p, 1080i, 1080p standards. Supported media file formats: MP3, MPEG4, Xvid, DivX, JPEG.
The power of the acoustic system of sound is 10 W (2x5 W), provided by two speakers. The NICAM stereo audio processing system and the Sound Surround function are used.
Communication with other devices via an external interface is supported by standard input and output connectors: antenna input (RF), AV, component, SCART, RGB, VGA, HDMI, MHL, USB. A headphone jack is provided. A VGA (D-Sub 15) connector is provided to connect a computer or laptop to this TV model. This interface supports standard resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.

The power consumed when operating from the mains is 30 W. External power supply Adapter 24V.

Dimensions: With stand 513x362x140 mm, Without stand 513x320x63 mm.

Attention! Panel LC216EXN LED-TV LG 22LN457U is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.