Technical description and composition of the LG 43UJ750V TV, panel type and modules used. The composition of the modules.LG LED
Model: 43UJ750V
Chassis / Version: UB / D / J71P UJ75 EP1
Panel: LC430EGG (FK) (M1)
LED backlight: 6916L3025A, 6916L3024A
LED driver (backlight): integrated into PSU
MOSFET LED driver: TO-252
Power Supply (PSU): EAX67262601 (1.5) EAY64528801
PWM Power: PFC, PWM
MOSFET Power: TO-252
MainBoard: EAX67148503 (1.0)
IC MainBoard: CPU, eMMC, DRAM, AUDIO, DC / DC
Tuner: TDJN-G501D EBL61841001
Control: WI-FI: EAT63377302, IR: EBR83592201
Specifications 43UJ750V
LG 43UJ750V
General recommendations for TV LCD LED repair
Possible manifestations of defects
- LG 43UJ750V 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.
Usually with similar manifestations, the defect is caused by faulty elements in the main power supply module EAX67262601. Its output voltages should be measured and, in their absence, the serviceability of the power switches (TO-252) and rectifier diodes in the converters should be checked for possible breakdown.
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.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements, which can disable it in key mode, or provoke an excess of the maximum current or voltage values. These can be circuits supplying the PWM controller, damper or frequency setting circuits, or OOS (negative feedback) elements in the stabilization circuit. PWM controllers (PWM) PFC, PWM, in the absence of external damage and short circuit between the terminals, are checked by replacing them with known good ones.
- There is no picture, but there is sound and reaction to commands from the remote control. Or the image appears immediately after switching on and disappears.
In some of these cases, the malfunction is caused by the lack of display backlighting. 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,
Without a special current source, it is impossible to check the line of series-connected LEDs, and it is unsafe for them to use any voltage sources over 12V for this purpose. Then all that remains is to open the panel and check each LED separately. Typically, Chinese multimeters with a 9V power supply lightly light up one 3-volt LED if you connect the probes to it in the forward direction, the red probe to the anode, and the black one to the cathode. For dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of LED health. In the event of a malfunction of the LED, its zener diode will either be cut off, or broken through in 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 EAX67148503 motherboard should start with checking the stabilizers and power converters required to power the microcircuits and matrix. If necessary, you should update or replace the software (software). Complicated repair of MB (SSB) board is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the elements of the CPU, eMMC, DRAM, AUDIO, DC / DC. BGA chip faults are usually easy to detect by warm-up.
The malfunction of the tuner TDJN-G501D EBL61841001 is established after checking the software and all supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be monitored with an oscilloscope.
Attention! Users and owners of 43UJ750V 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 : UD71P for models 43UJ750* 43UJ750*-ZB, 43UJ7507, 43UJ750V
Additional MainBoard RepairThe appearance of the MainBoard EAX67148503 is shown in the figure below:
EAX67148503
External view of the power supply
Main features of the LG 43UJ750V device:
Installed matrix (LED-panel) LC430EGG (FK) (M1).
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 43UJ750V TV is carried out by the EAX67262601 power module, or its analogues using PFC, PWM microcircuits and TO-252 type power switches.
MainBoard - the main board (motherboard) is an EAX67148503 module using CPU, eMMC, DRAM, AUDIO, DC / DC and others.
Tuner TDJN-G501D EBL61841001 provides reception of television programs and tuning to channels.
LG 43UJ750V TV with LCD LC430EGG (FK) (M1), 42.5 "(108 cm) 16: 9 format diagonal. This model uses an edge LED panel with LED backlighting.
The LC430EGG sensor and MainBoard EAX67148503 software are capable of realizing images in the highest UHD quality 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.
TV model 43UJ750V has SMART firmware 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 EAX67262601 power supply.
Dimensions: with stand 968x629x214 mm, without stand 968x566x62 mm.
TV weight: with stand: 11.4 kg, without stand: 10.2 kg.
Attention! The LC430EGG panel of the LG 43UJ750V 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.