Monday 14 September 2020

REPAIRING / SERVICING TV LG 49UJ651V

Technical description and composition of the LG 49UJ651V TV, panel type and modules used. The composition of the modules.
LG LED
Model: 49UJ651V
Chassis / Version: LJ7 Chassis
Panel: LC490DGG (FK) (M4)
LED backlight: 6916L-2862A, 6916L-2863A V17 49 L1, V17 49 R1
LED driver (backlight): integrated into PSU 650mA
PWM LED driver: MAP3516
MOSFET LED driver: MDD7N25
Power Supply (PSU): EAX67128101 (2.1) EAY64491201
PWM Power: SSC3S927
MainBoard: EAX67133404 (1.0)
IC MainBoard: Realtek K3Lp, FT24C256A, DTA2010M
Tuner: TDJN-G501D
Specifications 49UJ651V
LG 49UJ651V
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- The LG 49UJ651V TV does not turn on and does not show any signs of operability at all. No response to the remote control and front panel control buttons.
Usually with similar manifestations, the defect is caused by faulty elements in the main power supply module EAX67128101. Then you should measure its output voltages and, in case of their complete or partial absence, it is necessary to check the serviceability of the power switches and rectifier diodes of the converters for the presence of a possible short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in short-circuit mode, and in case of short-circuit in the elements of the primary circuit, the mains fuse usually breaks off.
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) SSC3S927 are usually checked by replacing them with new ones, or knowingly working.
- 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.
As a rule, in this case, the backlight of the LED panel is faulty. The reason can sometimes be in the power supply of the LEDs, but more often in their malfunction (breakdown or breakage), sometimes in the violation of the contact connections of the LED strips.
To test the LED strips, in order 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 junctions in forward bias, you can sometimes detect the presence of a protective zener diode PN junction by connecting the probes in the opposite direction. If the zener diode is cut off or broken in K / Z, then the LED is faulty and needs to be replaced.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals the standby mode.


 If LG 49UJ651V has no picture, but there is sound, often the LCD backlight LC490DGG (FK) (M4) 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 LC490DGG LCD panel, a process that requires experience and qualifications from the technician. 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 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.

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 complex MB (SSB) repairs and with the necessary skills and equipment, it may sometimes be necessary to replace its Realtek K3Lp, FT24C256A, DTA2010M chips and other possible faulty components. Malfunctions associated with the use of BGA soldering technologies are usually easily diagnosed by the warm-up method.
Before replacing the TDJN-G501D tuner, if there is no tuning to the channels, you must first check the software and the supply voltage at its outputs. You also need to make sure that the tuner and processor can exchange data via the I2C bus
Attention! Users and owners of 49UJ651V TVs who do not have the appropriate qualifications, knowledge and experience are strongly discouraged from trying to repair themselves in order to avoid negative consequences that can lead to the complete non-repairability of the device.


DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    CHASSIS : UD74P for models    49UJ65** 49UJ65**-ZA, 49UJ6517, 49UJ651V


https://4.bp.blogspot.com/-4Mn-87ZrwOE/X18jeTCJNHI/AAAAAAABG3k/R9iTa8A0dFwIkTAG2Mx6Q0vhndzpaFdLACK4BGAYYCw/s1600/EAX67133404_DCE.jpgAdditional 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 49UJ651V device:
Installed matrix (LED-panel) LC490DGG (FK) (M4).
A converter combined with a power supply is used to power the backlight LEDs, it is controlled by the MAP3516 PWM controller. The keys of the MDD7N25 type are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the LG 49UJ651V TV is carried out by the EAX67128101 power supply module, or its analogs using SSC3S927 microcircuits.
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 49UJ651V 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 MFL69668903_02_Q_ENG.pdf English 06.11.2017 23361K
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_ENG.pdf English 06.11.2017 4926K

Files can be downloaded from the manufacturer's website for the 49UJ651V model.



LG 49UJ651V TV with LCD display LC490DGG-FKM3, diagonal size 48.5 "(123 cm) 16: 9 format. The LCD panel implements the principle of direct backlight display with rear LEDs - Direct LED.
The LC490DGG-FKM3 sensor and MainBoard EAX67133404 software are capable of realizing the highest UHD quality image at 3840x2160 resolution in 4K UHD, HDR. Image processing is performed using modern High Dynamic Range (HDR) technology with an extended range of brightness gradations.
The 49UJ651V 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 EAX67128101 power supply.
Dimensions: With stand 1107x705x233 mm, Without stand 1107x645x79 mm.
Attention! The LC490DGG-FKM3 panel of the LG 49UJ651V 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.