Technical description and composition of the LG 42LM615T TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 42LM615T
Chassis / Version: LD21B
Panel: LC420EUE (SE) (F1)
LED backlight: 6922L-0016A, 6920L-0001C
T-CON: 6870C-0414B
LED driver (backlight): integrated into PSU; 67V 0.78A
PWM LED driver: R5F100BCAFP, AAT2430AISX
MOSFET LED driver: PHT4NQ10LT * 4
Power Supply (PSU): EAX64427101 LGP4247L-12LPB
PWM Power: FAN7930BG (PFC), L6599AD (PWM Resonant), STR-A6059, FDT86106LZ
MOSFET Power: K10A60D, 13NM60V
MainBoard: EAX64909901
IC MainBoard: LGE2111A-T8, NAND FLASH: H27U1G8F2BTR / BC - 1 Gbit (128M x 8 bit), SPI: W25Q80, EEPROM: 24C256, AUDIO: STA380BWE
Tuner: TDSN-G301D
Specifications 42LM615T
LG 42LM615T
General repair guidelines for TV LCD LED
If the LG 42LM615T does not turn on, no control lights on the front panel are on or blinking, therefore, there is a very high probability of a malfunction of the EAX64427101 LGP4247L-12LPB power module. In some cases, only the processor power regulator may be faulty. Diagnostics and repair of the common power supply should always begin with a check of the mains fuse and the condition of the electrolytic capacitors of the secondary rectifier filters. Defective and swollen capacitors should be replaced with new ones. If the fuse breaks, it is advisable to check for a breakdown, first of all, all power semiconductor elements of the converter and the diode bridge of the rectifier network, as well as a large electrolytic capacitor of the filter of the rectifier network.
If the LG 42LM615T does not have an image, but there is sound, there may be a malfunction of the backlight LEDs of the LC420EUE (3D) panel or their power converter, which is integrated into the general PSU module LGP4247L-12LPB.
The lack of backlight often occurs due to an open circuit in the LED circuit. In this case, it becomes necessary to disassemble the panel and check the LEDs themselves, as well as the same contact connections in the connectors and rations of the terminals.
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.
In cases of attempts to repair the motherboard EAX64909901, it is necessary to check the operability of the linear stabilizers and power converters of its microcircuits and, if possible, update the software (software). BGA chips can sometimes be diagnosed with local heating.
In some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - LGE2111A-T8, NAND FLASH: H27U1G8F2BTR / BC - 1 Gbit (128M x 8 bit), SPI: W25Q80, EEPROM: 24C256, AUDIO: STA380BWE with new or known serviceable.
Before replacing the TDSN-G301D tuner, if there is no tuning to the channels, you must first check the software and the supply voltage at its terminals, as well as using an oscilloscope to verify that the tuner is exchanging data with the processor.
Remember! Attempts at self-repair by users of the LG 42LM615T TV without the appropriate qualifications and the necessary experience can lead to serious negative consequences!
SCHEMATIC DIAGRAM ---------> LG CHASSIS LD21B MODEL: 42LM615S, 42LM615S-ZE, 42LM615T, 42LM615T-ZE.
PSU SCHEMATIC DIAGRAM ---------> LG EAX64427101 EAY62608901 LGP4247L-12LPB PLDF-L103A
To reduce the backlight current in LED drivers with the AAT2430AISX controller, increase the resistance of the resistor from terminal 50 (ISET) to the housing, for example, from 3 KOhm to 4.7 KOhm. Currents will proportionally decrease in each of the 16 channels. With a parallel connection of channels, currents are summed.
The appearance of the MainBoard EAX64909901 is shown in the figure below:EAX64909901
EAX64909901 can be used on TVs:
LG 42LM580T-ZA (Panel LC420EUE (SE)(F1)), LG 42LM340T (Panel LC420DUN (SE)(U3)), LG 32LM580T (Panel LC320EUN (SE)(F3)), LG 42LM585T ZD (Panel LC420EUE (SE)(F1)), LG 42LM615T (Panel LC420EUE (SE)(F1)), LG 42LS560T 42LS560T-ZC (Panel T420HVN01.1).
PSU Advanced
The 42LM615T is equipped with an EAX64427101 power supply module using the PFC (Power Factor Correction) scheme, which acts as an active filter to eliminate the higher harmonic components of the current consumption. The boost converter based on the FAN7930BG PWM controller does not allow the input rectifier filter's electrolytic capacitor to be connected to the network directly through open diodes when the charge current determines its reactance (about 15-30 ohms at a frequency of 50 Hz). As a result of the conversion, the charging current of the capacitor will be determined in such a way that the envelope of the high-frequency pulses of the input current will repeat the phase and shape of the sine wave of the input voltage. The health check of the PFC unit is carried out by measuring the DC voltage on the capacitor of the rectifier network. In operating mode, it should be around 380V, in standby approximately 300V.
The appearance of the power supply
Main features of the device LG 42LM615T:
Installed matrix (LED-panel) LC420EUE (SE) (F1).
The matrix control uses the Timing Controller (T-CON) 6870C-0414B.
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by a PWM controller R5F100BCAFP, AAT2430AISX. As power elements of the LED driver, keys of the type PHT4NQ10LT * 4 are used.
The necessary supply voltages for all nodes of the LG 42LM615T TV are generated by the EAX64427101 power supply module or its analogs using FAN7930BG (PFC), L6599AD (PWM Resonant), STR-A6059, FDT86106LZ microchips and power switches of the K10A60D, 13NM60V type.
MainBoard - the main board (motherboard) is an EAX64909901 module using LGE2111A-T8 chips, NAND FLASH: H27U1G8F2BTR / BC - 1 Gbit (128M x 8 bits), SPI: W25Q80, EEPROM: 24C256, AUDIO: STA380BWE and others.
The TDSN-G301D tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC420EUE-SEF1
Type: a-Si TFT-LCD, Panel
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 930.24x523.26 mm
Surface: Antiglare (Haze 1%), Hard coating (3H)
Brightness: 360 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 16.7M (8-bit), CIE1931 68%
Response Time: 6 (G to G)
Frequency: 60Hz
Lamp Type: 6 strings WLED Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V