Wednesday, 27 January 2021

REPAIRING / SERVICING TV LG 43LK5400PLA

Technical description and composition of the LG 43LK5400PLA TV, panel type and modules used. The composition of the modules.

LG LED
Model: 43LK5400PLA 43LK5400PLA

Chassis / Version: EAX67703503

Panel: K430WDK5

T-CON: 6870C-0532A

LED driver (backlight): integrated into PSU

PWM LED driver: MP3398E DIP-16

MOSFET LED driver: TO-252

Power Supply (PSU): K-PL-0M1 4702-2PL0M1-A4131L01

PWM Power: SO-8

MOSFET Power: TO-220

MainBoard: EAX67703503 (1.1)

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

Tuner: TDJA-G601D

Specifications 43LK5400
LG 43LK5400PLA
General recommendations for TV LCD LED repair
Possible manifestations of defects

- LG 43LK5400PLA TV does not turn on. There are no signs of operability. The indicators on the front panel do not light or blink, the TV does not respond to control buttons.

In such cases, the fault should be looked for first of all in the power supply module K-PL-0M1. Its output voltages should be measured, and if they are absent, check the serviceability of the power switches (TO-220) of the converters and rectifier diodes for the probability of a 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 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) SO-8, if they do not have visible damage to the case and an outright short circuit between the terminals, are usually checked by replacing.

- There is no image, the screen is black, there is sound, sometimes you can see barely noticeable outlines of the image in the ambient light of the screen.

The backlight of the matrix (LED panel) is usually faulty in these cases. The reason may be found in the malfunction of the LEDs, in the violation of the contact connections of the LED strips, or in the provision of their power supply (LED driver).
It is impossible to check the LED bars for a break without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts is required, and ideally a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters tend to light one 3-volt LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as an indicator of serviceability. In faulty LEDs, the zener diode will either be cut off, or pierced in the K / Z.

If the LG 43LK5400 has no picture, but there is sound, the backlight of the K430WDK5 display 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 K430WDK5 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 you can see light 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 EAX67703503 often turns out to be faulty, a software failure is also possible.
Then, first of all, you need 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 the normal range, it is necessary to trace the passage of LVDS signals from the MainBoard EAX67703503 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.

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


- 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 EAX67703503 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). Sometimes it is necessary to check or replace (if necessary) elements of the MainBoard - CPU, eMMC, SPI Flash, DRAM, AUDIO, DC / DC. In cases where a BGA processor is used, its malfunction is usually detected by a local 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 TDJA-G601D tuner and update the software. I2C communication pulses must be monitored with an oscilloscope.

Attention to TV owners! Attempts to repair LG 43LK5400PLA on their own are not recommended by the manufacturer and can lead to serious negative consequences  ( IDIOTS ARE ADVISED ) !

Additional MainBoard Repair

The appearance of the MainBoard EAX67703503 is shown in the figure below:






EAX67703503

External view of the power supply

Main features of the LG 43LK5400PLA device:

Installed matrix (LED-panel) K430WDK5.
Matrix control uses the 6870C-0532A Timing Controller (T-CON).
A converter combined with a power supply is used to power the backlight LEDs, it is controlled by the MP3398E DIP-16 PWM controller. TO-252 switches are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the LG 43LK5400PLA TV is carried out by the K-PL-0M1 power module, or its analogs using SO-8 microcircuits and TO-220 power switches.
MainBoard - the main board (motherboard) is an EAX67703503 module, using CPU, eMMC, SPI Flash, DRAM, AUDIO, DC / DC chips and others.
Tuner TDJA-G601D provides reception of television programs and tuning to channels.


Instructions and updates

There are files to download for the 43LK5400PLA model from the manufacturer:

Files with updates and instructions:
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). Update instructions TV_Software_Update_Guide_v3.pdf PDF 03/26/2020 2014K

User Manuals and Instructions:
Document Language Date Size
Quick Start Guide English - English, Estonian, Latvian, Lettish, Lithuanian, Russian 05/11/2020 55 037K
Quick Start Guide English - English, Estonian, Latvian, Lettish, Lithuanian, Russian 05/11/2020 No data
Quick start instructions English - English 08.09.2018 4067K

The files can be downloaded from the manufacturer's website for the 43LK5400PLA model.


TV LG 43LK5400 with LCD K430WDK5, diagonal 42.5 "(108 cm) 16: 9 format. The LCD panel implements the principle of direct backlight display with rear LEDs - Direct LED.
The K430WDK5 sensor and the MainBoard EAX67703503 software provide viewing of broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphics resolution at 1080p (Full HD). Image processing is performed using modern High Dynamic Range (HDR) technology with an extended range of brightness gradations.
The 43LK5400 TV model has SMART firmware and webOS operating system installed. The connection to the network can be carried out via Wi-Fi wireless connection. Supported media file formats: MP3, WMA, MPEG4, HEVC (H.265), Xvid, DivX, MKV, 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, HDMI x2, USB, Ethernet (RJ-45), Wi-Fi 802.11ac, Miracast. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.

The TV uses the K-PL-0M1 power supply.

Attention! Panel K430WDK5 LED TV LG 43LK5400 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.