Technical description and composition of the LG 43UJ634V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 43UJ634V
Chassis / Version: UD74P
Panel: AC430DGG
LED backlight: LC43490059
LED driver (backlight): integrated into PSU; 68V 650mA
Power Supply (PSU): EAX67209001 (1.5) LGP43DJ-17U1
MainBoard: EAX67133404 (1.0) RS84951F4Z
IC MainBoard: Realtek K3Lp, FT24C256A, DTA2010M
Tuner: TDJN-G501D p / n: EBL61841001
Control: IR: EBR83592701, Wi-Fi: LGSBWAC72 EAT63377302
Specifications 43UJ634V
LG 43UJ634V
General repair guidelines for TV LCD LED
Possible malfunctions
- LG 43UJ634V does not turn on, the indicators on the front panel do not light or flash. The TV does not respond to the control buttons and the remote control.
In some of these cases, a malfunction is detected in the EAX67209001 power module. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, it is necessary to check the serviceability of power switches and rectifier diodes for possible breakdown (short circuit).
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during short circuit in the elements of the primary circuit, the mains fuse usually breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM), in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, but there is sound and reaction to commands from the remote control. Or the image appears immediately after turning on and disappears.
As a rule, in such cases there is no display backlight. The reason can be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
To check the LED strips, to open all the transitions of the LEDs, several tens of volts or more are needed, it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED transitions in forward bias, sometimes you can detect the presence of a PN junction of the protective zener diode by connecting the probes in the opposite direction. If the zener diode is broken or broken in short-circuit, then the LED is faulty and needs to be replaced.
- The TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the EAX67133404 motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software).
If there is no reception of television channels, but the TV is working properly from external devices, first of all it is necessary to check the voltage of the tuner TDJN-G501D p / n: EBL61841001 and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
If LG 43UJ634V has no picture, but there is sound, often the backlight of the AC430DGG display 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 AC430DGG 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 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 EAX67133404 often turns out to be faulty, a software failure is also possible.
Then, first of all, 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 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.
TV users and owners need to remember that attempts to self-repair a LG 43UJ634V TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> LG 43UJ634V, 43UJ635V Chassis UD74P for 43UJ634V, 43UJ634V-ZD, 43UJ635V, 43UJ635V-ZF
The appearance of the MainBoard EAX67133404 is shown in the figure below:EAX67133404
The appearance of the power supply
Main features of the device LG 43UJ634V:
Installed matrix (LED-panel) AC430DGG.
To power the backlight LEDs, a converter is used, combined with a power supply.
The formation of the necessary supply voltages for all nodes of the LG 43UJ634V TV is carried out by the EAX67209001 power module, or its analogues.
MainBoard - the main board (motherboard) is an EAX67133404 module, using Realtek K3Lp, FT24C256A, DTA2010M chips, and others.
Tuner TDJN-G501D p / n: EBL61841001 provides the reception of television programs and tuned to channels.
TV LG 43UJ634V with LCD AC430DGG, diagonal size 42.5 "(108 cm) 16: 9 format. The LCD panel implements the principle of direct display backlighting with rear LEDs - Direct LED.
AC430DGG sensor and MainBoard EAX67133404 software are capable of realizing images in the highest UHD quality at a resolution of 3840x2160 pixels in 4K UHD, HDR. Image processing is performed using modern High Dynamic Range (HDR) technology with an extended range of brightness gradations.
TV model 43UJ634V 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 x3, USB x2, Ethernet (RJ-45), Bluetooth, Wi-Fi 802.11ac, WiDi, Miracast.
The digital tuner can receive TV channels in the DVB-T MPEG4, DVB-C, DVB-T2, DVB-S2 standards.
The TV uses an EAX67209001 power supply.
Dimensions: with stand 977x615x187 mm, without stand 977x575x81 mm.
TV weight: with stand: 8.4 kg, without stand: 8.3 kg.
Attention! The AC430DGG panel of the LG 43UJ634V 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.