Technical description and composition of the LG 49UJ631V TV, panel type and modules used. The composition of the modules.LG LED
Model: 49UJ631V
Chassis / Version: LJ7
Panel: SDL490W0 (LD0-B11)
LED backlight: JL.D49091330-001FS-M
LED driver (backlight): integrated into PSU
MOSFET LED driver: TO-252
Power Supply (PSU): LGP49DJ-17U1 EAX67189201 (1.6)
PWM Power: PFC, PWM
MOSFET Power: TO-252
MainBoard: EAX67133404 (1.0) T74P D74D
IC MainBoard: Realtek K3Lp, FT24C256A, DTA2010M
Tuner: TDJN-G501D EBL61841001
Control: Wi-Fi: LGSBWAC72 EAT63377302, IR: EBR83592701 UJ65_V1.0
Specifications 49UJ631V
LG 49UJ631V
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- LG 49UJ631V does not turn on, indicators on the front panel do not light or flash. The TV does not respond to the control buttons and the remote control.
Most likely, in this case, the main switching power supply (SMPS) LGP49DJ-17U1 is faulty. It is necessary to measure its secondary output voltages, and if they are absent, check the power switches (TO-252) and rectifier diodes in the converters for a short circuit.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in an emergency mode of short circuit without output voltages, and with a short circuit in the elements of the primary circuit, the mains fuse most often breaks off immediately and, less often, the current sensor in the source of the key.
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) PFC, PWM, if they do not have visible damage to the case and an outright short circuit between the pins, are usually checked by replacement.
- There is no picture, but there is sound and reaction to the remote control. Or, for a second, the image may appear immediately after switching on.
In such cases, a malfunction of the LED panel backlighting elements is most likely. The reason may be in the breakage of the LEDs, in the stabilization of their power supply, or in the violation of the contact connections of the strings connectors,
To check the LED strips for breakage without disassembling the panel, for example, a current source will help. It is impossible to open series-connected PN junctions with a simple multimeter; a voltage of the order of several tens of volts is required.
If LG 49UJ631V has no picture, but there is sound, often the SDL490W0 display backlight (LD0-B11) 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 LCD panel SDL490W0 (LD0-B11) - 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 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 often the main board MainBoard EAX67133404 turns out to be faulty, a software failure is also possible.
Then, first of all, it is necessary 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 MainBoard EAX67133404 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 TV does not turn on, the indicator signals the standby or operating mode, or blinks.
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). Often the MB (SSB) board needs to be replaced in the event of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - Realtek K3Lp, FT24C256A, DTA2010M and replace the failed chips with new ones. Some malfunctions can be associated with the use of BGA soldering technologies in modern Main Board. Typically, such defects are detected by local heating of the chip.
If you suspect a malfunction of the TDJN-G501D EBL61841001 tuner, first of all, you need to make sure that the software is correct, as well as the presence of the necessary levels of supply voltages and pulses of data exchange with the processor via the I2C bus on the corresponding terminals of the tuner.
Owners and users of the LG 49UJ631V TV should remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to the complete non-repairability of the device!
Additional MainBoard RepairThe appearance of the MainBoard EAX67133404 is shown in the figure below:
EAX67133404
External view of the power supply
Main features of the LG 49UJ631V device:
Installed matrix (LED panel) SDL490W0 (LD0-B11).
A converter combined with a power supply is used to power the backlight LEDs. 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 49UJ631V TV is carried out by the LGP49DJ-17U1 power module, or its analogs using PFC, PWM microcircuits and TO-252 power switches.
MainBoard - the main board (motherboard) is an EAX67133404 module, using Realtek K3Lp, FT24C256A, DTA2010M and others.
Tuner TDJN-G501D EBL61841001 provides reception of television programs and tuning to channels.
TV LG 49UJ631V with LCD SDL490W0 (LD0-B11), diagonal size 48.5 "(123 cm) 16: 9 format. The LCD-panel implements the principle of direct backlight display with rear-mounted LEDs - Direct LED.
SDL490W0 (LD0-B11) sensor and MainBoard EAX67133404 software are capable of realizing images in the highest UHD quality at 3840x2160 pixels in 4K UHD, HDR. Image processing is performed using modern High Dynamic Range (HDR) technology with an extended range of brightness gradations.
The 49UJ631V 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 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 power consumed when operating from the network is 120 W. LGP49DJ-17U1 power supply.
Dimensions: with stand 1110x705x235 mm, without stand 1110x650x81 mm.
TV weight: with stand: 11.4 kg, without stand: 11.3 kg.
Attention! The SDL490W0 (LD0-B11) panel of the LG 49UJ631V 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.