Monday, 14 September 2020

REPAIRING / SERVICING TV LG 43UJ670V

Technical description and composition of the LG 43UJ670V TV, panel type and modules used. The composition of the modules.
LG LED
Model: 43UJ670V
Chassis / Version: LJ7 Chassis
Panel: LC430DGG (FK) (M3)
LED backlight: 6916L-2867A
LED driver (backlight): integrated into PSU
Power Supply (PSU): EAX67267601 LGP43D-17U2
MainBoard: EAX67133404 (1.0) EBU64553903
IC MainBoard: Realtek K3Lp, FT24C256A, DTA2010M
Tuner: TDJN-G501D
Control: WiFi: LGSBWAC72, IR: UJ65_V1.0 EBR83592301
Specifications 43UJ670V
LG 43UJ670V
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- LG 43UJ670V 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 the control buttons.
With such manifestations, the power supply module EAX67267601 usually fails. It is necessary to measure its output voltages, and in the event of their absence (full or partial), the serviceability of the power switches of the converters and rectifier diodes should be checked for a possible short circuit.
In case of breakdowns of semiconductors in the secondary circuits, the converter can usually work in an emergency in the short-circuit mode, and with a short circuit in the power elements of the primary circuit, the mains fuse often breaks.
Breakdown of Mos-Fet switches 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) are usually checked by replacing them with new ones, or knowingly working.
- There is no picture, but there is sound and all other functions work. Sometimes when you turn it on, the image appears and disappears for a second.
The backlight of the matrix (LED panel) is usually faulty in these cases. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
It should be remembered that it is not possible to determine an open circuit in the LED lines without disassembling the panels using a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required. Then you need to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow opening the LED in the forward direction or dual LEds are used, then the PN transition of the emergency zener diode can indirectly serve as an indicator of serviceability. In the event of a malfunction of the LED-a, the PN-junction of the zener diode will either be cut off or broken into the K / Z.
- 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 EAX67133404 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 attempts to repair the MB (SSB) board, it is necessary to check the serviceability of its elements - Realtek K3Lp, FT24C256A, DTA2010M which may require replacement with new ones. If a BGA processor is installed, there is a possibility of a violation of the soldering of the contacts of its pins with the board (detected by warming up).

 If LG 43UJ670V has no picture, but there is sound, often the LCD backlight LC430DGG (FK) (M3) 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.
To replace the LEDs, disassembling the LC430DGG LCD panel is required (- 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 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 EAX67133404 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 the normal range, it is necessary to trace the passage of LVDS signals from the MainBoard EAX67133404 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.

If the TV operates normally from external devices but does not tune to TV channels, the TDJN-G501D tuner may be faulty. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the reason for the inoperability of the tuner may be a software failure.
Attention to users! Self-repair of the LG 43UJ670V TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!

 DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>   CHASSIS : UD74P for models    43UJ67*V, 43UJ67*V-ZD, 43UJ67*V-ZC, 43UJ655V 43UJ655V-ZC, 43UJ701V 43UJ701V-ZC, 43UJ670V, 43UJ675V



Additional MainBoard Repair
The appearance of the MainBoard EAX67133404 is shown in the figure below:
EAX67133404
External view of the power supply
Main features of the LG 43UJ670V device:
Installed matrix (LED panel) LC430DGG (FK) (M3).
A converter combined with a power supply is used to power the backlight LEDs.
The formation of the necessary supply voltages for all nodes of the LG 43UJ670V TV is carried out by the EAX67267601 power module, or its analogs.
MainBoard - the main board (motherboard) is an EAX67133404 module, using Realtek K3Lp, FT24C256A, DTA2010M and others.
Tuner TDJN-G501D provides reception of television programs and tuning to channels.

 There are files to download for the 43UJ670V model from the manufacturer:
Files with updates and instructions:
File Description File Name Type Date Size
SW File (Version 05.80.50). Update instructions TV_Software_Update_Guide_v3.pdf PDF 01/22/2020 2014K
SW File (Version 05.80.50). Firmware (USB) Software_File (Version_05.80.50) .zip ZIP 01/22/2020 831673K
Compatible with 43UJ620V-ZA, 43UJ6307-ZA, 43UJ6309-ZA, 43UJ630V-ZA, 43UJ631V-ZA, 43UJ634V-ZD, 43UJ635V-ZF, 43UJ639V-ZE, 43UJ6517-ZA, 43UJ6519-ZA, 43UJ651V-ZA, 43UJ655V-ZC, 43UJ670V-ZD, 43UJ675V-ZC, 43UJ701V-ZC, 49UJ620V-ZA, 49UJ6307-ZA, 49UJ6309-ZA, 49UJ630V-ZA, 49UJ631V-ZA, 49UJ634V-ZD, 49UJ635V-ZF, 49UJ639V-ZE, 49UJ6517-ZA, 49UJ6519-ZA, 49UJ651V-ZA, 49UJ655V-ZC, 49UJ670V-ZD, 49UJ675V-ZC, 49UJ701V-ZC, 55UJ620V-ZA, 55UJ6307-ZA, 55UJ6309-ZA, 55UJ630V-ZA, 55UJ634V-ZD, 55UJ635V-ZF, 55UJ6517-ZA, 55UJ6519-ZA, 55UJ651V-ZA, 55UJ655V-ZC, 55UJ670V-ZD, 55UJ675V-ZC, 55UJ701V-ZC, 55UK6100PLA, 55UK6100PLB, 60UJ6307-ZA, 60UJ6309-ZA, 60UJ630V-ZA, 60UJ634V-ZD, 60UJ6517-ZA, 60UJ6519-ZA, 60UJ651V-ZA, 65UJ620V-ZA, 65UJ6307-ZA, 65UJ6309-ZA, 65UJ630V-ZA, 65UJ634V-ZD, 65UJ6517-ZA, 65UJ6519-ZA, 65UJ651V-ZA, 65UJ655V-ZC, 65UJ670V-ZD, 65UJ675V-ZC, 65UJ701V-ZC, 65UK6100PLA, 65UK6100PLB, 70UJ675V-ZA, 75UJ651V-ZB, 75UJ675V-ZA.

User Manuals and Instructions:
File type File name Language Date Size
User manual ENG.pdf English 05/16/2017 4339K

Quick Start Guide w3.5_mr_e05_c.zip English, Estonian, Latvian, Lettish, Lithuanian, Russian 10/31/2019 56,267K

Instructions for quick setup Web_OS_3.5_Smart_QSG_RUS.pdf Russian 13.09.2017 4888K

Files can be downloaded from the manufacturer's website for the 43UJ670V model.
  

LG 43UJ670V TV with LCD LC430DGG (FK) (M3), 42.5 "(108 cm) 16: 9 format diagonal. The LCD panel implements the principle of direct display backlighting with rear-mounted LEDs - Direct LED.
The LC430DGG matrix (and the MainBoard EAX67133404 main board software are capable of realizing the image in the highest UHD quality at a resolution of 3840x2160 pixels in the 4K UHD, HDR standard. Image processing is carried out using modern High Dynamic Range (HDR) technology with an extended range of brightness gradations.
43UJ670V TV model has built-in SMART software 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), DivX, MKV, JPEG.
Speaker sound system power 20 W (2x10 W) is 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 x4, USB x2, Ethernet (RJ-45), Bluetooth, Wi-Fi 802.11ac, WiDi, Miracast. A headphone jack is provided.
The digital tuner can receive TV channels in the DVB-T MPEG4, DVB-C, DVB-T2, DVB-S2 standards.
The TV uses an EAX67267601 power supply.
Dimensions: With stand 974x630x235 mm, Without stand 974x571x79 mm.
Attention! Panel LC430DGG (LED TV LG 43UJ670V 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.