Thursday, 31 December 2020

REPAIRING / SERVICING TV LG 43UF640V

Technical description and composition of LG 43UF640V TV, type of panel and modules used. Module composition.

LG LED
Model: 43UF640V

Chassis/Version: LD59R

Panel: HC430DGG-SLNX1-211X

LED backlight: UF64_UHD_A 43INCH

T-CON: 6870C-0647A 6871L-4293F

LED driver (backlight): integrated into MainBoard

MOSFET LED driver: TO-220F

Power Supply (PSU): EAX66472001 (1.5) EAY64009401

PWM Power: PFC, PWM (SSC3S921 )

MOSFET Power: TO-220, TO252

MainBoard: EAX66485504 (1.0) EBT63988801

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

TDJM-G301D EBL61560001

Specifications 43UF640V
LG 43UF640V
General recommendations for LCD LED TV repair
Possible defects

- LG 43UF640V TV does not turn on at all. No reaction to remote control and front panel control buttons. Indicator lights are not lit or blinking.

Often in such cases the power module EAX66472001 is defective. It is necessary to measure its output voltages, and in case of their absence (full or partial), check the condition of the power switches (TO-220, TO252) of the converters and the rectifier diodes for possible short circuits.
If there is a breakdown in the secondary circuits of the converter, it can usually fail in the short-circuit mode, and if there is a short circuit in the power elements of the primary circuit, most often the line fuse or the current sensor at the source of the key breaks.
Mos-Fet power switches used in switching 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 or damping circuits, or the negative feedback elements in the stabilization circuit. PFC, PWM controllers, if there is no visible damage or outright short circuits between pins, are checked by replacing with new or known good ones.

- No image, screen is black, there is sound, with external screen illumination sometimes you can see faintly visible outlines of the image.

In such cases, the most likely faulty elements of LED panel backlight. The cause may be in the breakage of backlight LEDs, in their power supply stabilization, or in the violation of the contact connections of UF64_UHD_A 43INCH string connectors.
When diagnosing you should take into account that it is impossible to check the breakage in the circuit of the LED strings without disassembling the panel, using a tester or multimeter. To open all the PN-junctions connected in series, you will need a voltage of about several tens of volts, and ideally - a current source. After opening the panel, you can check each LED separately. Typically, Chinese multimeters will light up a single 3 volt LED slightly if you connect the probes to it in a forward direction. For twin 6 volt LEDs, the PN junction of its fault stabilizer can be a good indicator. If the LED is faulty, it will either be broken or shorted.

If LG 43UF640V has no picture, but there is sound, often the HC430DGG-SLNX1 display backlight 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 when the external light hits the screen.

Replacing the LEDs requires disassembling the HC430DGG-SLNX1 LCD panel - a process that requires experience and qualifications from the master. We do not recommend doing such work on your own to TV owners 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 the light through the holes in the panel case.
In this case, the panel may also be faulty - damage to the 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 EAX66485504 (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, 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 MainBoard EAX66485504 (1.0) with an oscilloscope, as well as synchronization 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 TV set will not turn on, the LED will indicate standby or operation mode, or it will blink.

Repair or diagnosis of the motherboard EAX66485504 should begin with checking the stabilizers and power converters necessary to power the chips and matrix. If necessary, software (software) should be updated or replaced. In some cases to repair the MB board (SSB) you may need to replace the chips - CPU, eMMC, DRAM, DC/DC, AUDIO with new or known good ones. In cases where BGA technology is used, the defects are usually localized by the heating method.

Before you replace the TDJM-G301D EBL61560001 tuner if there is no tuning to the channels you should first check the software and the supply voltage on its outputs. Also you have to check the data exchange between the tuner and the processor via the I2C bus.

Please remember! Attempts to repair LG 43UF640V TV-set by yourself, in the absence of the necessary skills and experience are strongly not recommended and are fraught with negative consequences, up to the complete unusable device!

Driver current limit after backlight replacement. Information from the master.

You can reduce backlight current from 480 mA to 245 mA by removing one of each pair of low resistance current sensor resistors at the source of the converter keys (R811+R812 and R829+R830) on the EAX66472001 board.

DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>   CHASSIS : LD59R / LD5ZR  for models: 43UF640*, 49UF640*, 43/49UF640*-ZA, 43UF6407, 43UF640V, 49UF6407, 49UF640V.  


The appearance of the MainBoard EAX66485504 is shown in the figure below:

EAX66485504



MainBoard Appearance

The main features of the LG 43UF640V:

A matrix (LED panel) HC430DGG-SLNX1-211X is installed.
Timing Controller (T-CON) 6870C-0647A is used to control the matrix.
A converter combined with the main board EAX66485504 is used to power the backlight LEDs. As power elements of LED-driver are used TO-220F-type switches.
EAX66472001 power supply module or its analogues with the use of PFC and PWM chips (SSC3S921) and TO-220, TO252 power keys are used for generating necessary power supply voltages for all LG 43UF640V TV sets assemblies.
MainBoard - the main board (motherboard) is an EAX66485504 module, using CPU, eMMC, DRAM, DC/DC, AUDIO and other microchips.
The TDJM-G301D EBL61560001 tuner provides TV program reception and channel tuning.

Instructions and updates

There are files to download for the 43UF640V model from the manufacturer:

Files with updates and instructions:
File Description File Name Type Date Size
SW File (Version 03.16.00). Update instruction TV_Software_Update_Guide_v3.pdf PDF 18.06.2020 2014K
SW File (Version 03.16.00). Firmware (USB) Software_File (Version_03.16.00) .zip ZIP 06/18/2020 515617K
Compatible with 43UF6407-ZA, 43UF6409-ZA, 43UF640V-ZA, 49UF6407-ZA, 49UF6409-ZA, 49UF640V-ZA.
SW File (Version 03.15.50) for 43UF640V-ZA, 49UF640V-ZA, 43UF6407-ZA, 49UF6407-ZA. Update instructions TV_Software_Update_Guide_v3.pdf PDF 09.11.2017 1938K

User Manuals and Instructions:
Document Language Date Size
Quick Start Guide English - English, Estonian, Latvian, Lettish, Lithuanian, Russian 24/11/2015 13420K
Quick Start Guide English - English, Estonian, Latvian, Lettish, Lithuanian, Russian 24/11/2015 No data
User manuals English - English, Estonian, Latvian, Lettish, Lithuanian 08/09/2015 22 781K

Files can be downloaded on the manufacturer's website for the 43UF640V model.


LG 43UF640V TV with HC430DGG-SLNX1 LCD display, measuring 43" (109 cm) diagonally. (109 cm) in 16:9 aspect ratio. The display technology of this model features LED backlighting.
HC430DGG-SLNX1 matrix and MainBoard software EAX66485504(1.0) are able to realize the image in the highest quality UHD at 3840x2160 pixels in 4K UHD standard.
The 43UF640V has built-in SMART software and webOS Operating System. Connection to the network can be made via Wi-Fi wireless connection. 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, 2160p. Supported multimedia file formats are MP3, WMA, MPEG4, DivX, JPEG. Stereo sound is realized by two built-in speakers. A NICAM stereo sound processing system is used and the Sound Surround surround sound function.
Communication with other devices through an external interface is supported by standard input and output connectors: antenna input (RF), AV, audio x2, component, HDMI x2, USB, Ethernet (RJ-45), Wi-Fi. To connect a computer or laptop to this model of TV there is a VGA (D-Sub 15) connector. This interface supports standard resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080, 3840x2160. The digital tuner is capable of receiving television channels in the standards DVB-T, DVB-T2, DVB-C, DVB-S2.

The TV uses the EAX66472001(1.5) power supply.

Dimensions: C stand 975x621x209 mm, No stand 975x582x81 mm.

Warning. The HC430DGG-SLNX1 is an expensive and fragile part of your LG 43UF640V LED TV.
Do not allow any impact on the glass and pressure on the surface of the screen to avoid damage to 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.