Technical description and composition of the LG 43LJ500V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 43LJ500V ZB
Panel: TPT430H3-DUYSHA.G
LED backlight: GJ-2K16-430-D510-V4
T-CON: 6870C-0532A
LED driver (backlight): integrated into PSU
PWM LED driver: PF7909S
MOSFET LED driver: AOTF4126
Power Supply (PSU): 715G7574-P01-W07-0H2H
PWM Power: LD7591T, SSC3S121A
MOSFET Power: TK12A60W, AOTF12N65
MainBoard: 715G8524-M0F-B00-004T EBT64601901
IC MainBoard: NAND: W29N01GVSIAA
Tuner: TDQS-A751F (L) & TDSY-G430D
Control: IR: 715G8638-R01-000-004T
Specifications 43LJ500V
LG 43LJ500V
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 43LJ500V TV does not turn on, does not respond to the remote control and the control panel buttons, does not light up or blink indicators.
In some of these cases, a malfunction is detected in the 715G7574-P01-W07-0H2H power supply module. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, check the serviceability of the power switches (TK12A60W, AOTF12N65) and rectifier diodes for possible breakdown (short circuit).
In case of any breakdown of semiconductors in the secondary circuits, the converter can usually work normally in emergency short circuit mode. There are no output voltages. And with a short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and less often the current sensor at the source of the key.
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) LD7591T, SSC3S121A, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, there is sound, it is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
Usually in such cases, a malfunction is detected in the backlight nodes of the LED panel. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
To check the LED lines for breaks 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.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the 715G8524-M0F-B00-004T 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). When repairing an MB board, you must check its NAND components: W29N01GVSIAA. Defective items should be replaced. If chips with BGA soldering technology are used, a problem in its implementation is detected by the local heating of the chip.
If the TV works normally from external devices, but does not tune into television channels, the TDQS-A751F (L) & TDSY-G430D tuner may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
It should be remembered! Attempts to independently repair the LG 43LJ500V TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!
The appearance of the MainBoard 715G8524-M0F-B00-004T is shown in the figure below:715G8524-M0F-B00-004T
Main features of the device LG 43LJ500V:
Installed matrix (LED panel) TPT430H3-DUYSHA.G.
The matrix control uses the Timing Controller (T-CON) 6870C-0532A.
To power the backlight LEDs, a converter is used, combined with the power supply, controlled by the PF7909S PWM controller. As power elements of the LED driver, keys of the AOTF4126 type are used.
The necessary supply voltages for all nodes of the LG 43LJ500V TV are generated by the power module 715G7574-P01-W07-0H2H, or its analogs using microcircuits LD7591T, SSC3S121A and power switches of the type TK12A60W, AOTF12N65.
MainBoard - the main board (motherboard) is a module 715G8524-M0F-B00-004T, using NAND chips: W29N01GVSIAA and others.
The TDQS-A751F (L) & TDSY-G430D tuner provides TV reception and channel tuning.