Technical description and composition of the LG 42LF562V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 42LF562V
Chassis / Version: LD55H / LD55T
Panel: LC420DUE (MG) (A3)
LED backlight: LG lnnotek DRT 3.0 42_A type / 42_B type Rev01
T-CON: 6870C-0480A
LED driver (backlight): integrated into PSU
PWM LED driver: LC5901
Power Supply (PSU): EAX66203001 (1.7) LGP3942D-15CH1
MainBoard: EAX66203803 (1.0)
IC MainBoard: CPU: LGE2134, NAND Flash: TC58NVG0S3HTA00, SPI Flash: MX25L8035EM2I, EEPROM: 24C256
Tuner: TDJM-G301D
Control: IR: EBR78480602
Specifications 42LF562V
LG 42LF562V
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The LG 42LF562V TV does not turn on, does not respond to the remote control and the control panel buttons, the indicators do not light or flash.
Most often, with such manifestations, the main power supply module EAX66203001 is found to be faulty. It is necessary to measure its output voltages and, if they are absent, to check for short-circuit probabilities in the converters, power switches and rectifier diodes.
In case of any breakdowns in the secondary circuits, the converter can operate in emergency short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key more often breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM microcircuits are usually checked by replacement with new ones, or obviously working.
- There is no image, there is sound, it responds to the remote control, the channels are switched. In some cases, the image appears when you turn on and immediately disappears.
In some of these cases, the malfunction is caused by a lack of backlighting on the display. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It should be remembered that it is not possible to determine the open circuit in the LED lines without disassembling the panels with a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required. Then it is necessary to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow you to open the LED in the forward direction or dual LEd are used, then the PN junction of the emergency zener diode can indirectly serve as a health indicator. In case of LED-a failure, the zener diode PN junction will either be cut off or broken into short-circuit.
- The TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly or blinks.
Repair or diagnostics of the EAX66203803 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 need to check its CPU components: LGE2134, NAND Flash: TC58NVG0S3HTA00, SPI Flash: MX25L8035EM2I, EEPROM: 24C256. 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.
The TDJM-G301D tuner malfunction 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 controlled by an oscilloscope.
It should be remembered! Attempts to self-repair the LG 42LF562V 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!
SCHEMATIC DIAGRAM ---------> LG 42LF562V Chassis LD55H / LD55T
MODELS: 42LF5610-ZF (42LF560, 42LF561, 42LF562, 42LF564, 42LF560V, 42LF561V, 42LF562V, 42LF564V.
FIRMWARE SPI FLASH LG 42LF562V LD55H / LD55T, Main: EAX66203803 (1.0), Panel: LC420DUE (MG)(A3)
You can reduce the backlight current in televisions with LGP3942D-15CH1 power supplies (EAX66203001) by increasing the resistance of the current sensor. The nominal current in the LEDs is 250 mA. Current sensor - resistor R816 rated 3 Ohm. If you increase the rating to 4.3 Ohm, the current decreases to 175 mA.
The appearance of the MainBoard EAX66203803 is shown in the figure below:EAX66203803
The appearance of the power supply
Main features of the device LG 42LF562V:
Installed matrix (LED-panel) LC420DUE (MG) (A3).
The matrix control uses the Timing Controller (T-CON) 6870C-0480A.
To power the backlight LEDs, a converter is used, combined with the power supply, controlled by the LC5901 PWM controller.
The formation of the necessary supply voltages for all nodes of the LG 42LF562V TV is carried out by the EAX66203001 power module, or its analogues.
MainBoard - the main board (motherboard) is an EAX66203803 module using CPU chips: LGE2134, NAND Flash: TC58NVG0S3HTA00, SPI Flash: MX25L8035EM2I, EEPROM: 24C256 and others.
The TDJM-G301D tuner provides TV reception and channel tuning.