Technical description and composition of the LG 28TK410V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 28TK410V WZ
Chassis / Version: LD70A / MT49
Panel: HC275EXN-ABVP1-41XX
LED backlight: Edge 54 LED 3V 8020
T-CON: T-CON: HV280WX2-270_X-PCB; KLSTW1111, RT9955, i7975, I2111
LED driver (backlight): integrated into MainBoard
PWM LED driver: MP3378R
MOSFET LED driver: AOD2922
Power Supply (PSU): Adapter 19V
MainBoard: EAX67276303 (1.0)
IC MainBoard: LGE7311, MX30LF1G18AC, MX25L8005E, FT24C256A, M28722
Tuner: TDJA-G501D EBL61840901
Technical Specifications 28TK410V-WZ
LG 28TK410V
General repair guidelines for TV LCD LED
Possible malfunctions
- LG 28TK410V does not turn on, does not respond to buttons and remote control, indicators on the front panel do not light up and do not blink.
In such cases, the adapter power supply is usually faulty.
The TV is equipped with an adapter 19V external power supply, which the owner can purchase independently without repair, however, it is often easy to open and eliminate the simplest typical defects. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches and rectifier diodes for a possible partial or complete breakdown.
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.
Mos-Fet power switches, used in switching power supplies, sometimes fail due to a malfunction of any other elements that can put it out of operation in key mode or create an excess of the maximum permissible parameters of the switch. These can be elements supplying the PWM controller, frequency-setting or damping circuits, or negative feedback elements in the stabilization circuit. PWM controllers, in the absence of visible damage or frank short-circuit between the terminals, are checked by replacing with new, or obviously working.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
In some of these cases, the malfunction is caused by a lack of backlighting on the display. The reason can be found in the malfunction of the LEDs, in the violation of the contact connections of the LED strips, or in the provision of their power (LED driver).
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, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the EAX67276303 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). Board repair and replacement of LGE7311, MX30LF1G18AC, MX25L8005E, FT24C256A, M28722 microcircuits are carried out with the necessary equipment, and the corresponding element base. Faults associated with the application of BGA processor soldering technologies can be localized by the heating method.
Before changing the tuner TDJA-G501D EBL61840901, if it is not possible to tune to television channels, make sure that there are supply voltages that need to be measured at the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Attention TV owners! Attempts at self-repair of LG 28TK410V are not recommended by the manufacturer and can lead to serious negative consequences!
FIRMWARE FOR SPI FLASH, EEPROM ---------------> LG 28TK410V WZ LD70A / MT49, Main: EAX67276303 (1.0), Panel: HC275EXN-ABVP1-41XX.
To reduce the backlight current in LED drivers with the MP3378E PWM controller, it is necessary to proportionally increase the total resistance of the resistors from pin 3 (RISET) to the chassis. Calculation of current in milliamperes and resistance in kilo-ohms 977 / Rset for each channel. Parallel channels are summed. For example, for four parallel channels and a RISET 10 KOhm resistance, the total current will be 97.7 * 4 = 391 mA.
More details on this page
The appearance of the MainBoard EAX67276303 is shown in the figure below:EAX67276303
Main features of the device LG 28TK410V:
Installed matrix (LED panel) HC275EXN-ABVP1-41XX.
The matrix control uses the Timing Controller (T-CON) T-CON: HV280WX2-270_X-PCB ;.
To power the backlight LEDs, a converter is used, combined with the EAX67276303 main board, controlled by the MP3378R PWM controller. As power elements of the LED driver, keys of the AOD2922 type are used.
To power all the internal components of the LG 28TK410V TV, an external adapter 19V type source is used.
MainBoard - the main board (motherboard) is an EAX67276303 module, using chips LGE7311, MX30LF1G18AC, MX25L8005E, FT24C256A, M28722 and others.
The TDJA-G501D EBL61840901 tuner provides TV reception and channel tuning.