Technical description and composition of the LG 42LH4000 TV, panel type and applicable modules. The composition of the modules.LG
Model: 42LH4000 ZA
Chassis / Version: LD91G
Panel: LC420WUH (SB) (A1)
T-CON: EAX58017201 (9) (SB) (A1) LD91G EBR58803601
Inverter (backlight): integrated into PSU
PWM Inverter: BD9215F
Trans Inverter: LIF42-001 FLB-2
Power Supply (PSU): EAX55357701 / 32 LGP42-09LF
PWM Power: STR-W6252, ICE2PCS06 (PFC)
MOSFET Power: 07N60C3
MainBoard: EAX60686904 (2) EBU60710801
IC MainBoard: CPU: LGE3368A-LF-SF, NAND: FLASH: HY27US08121B-TPCB, SPI FLASH: W25X32VSSIG, EEPROM: M24512
Tuner: TDFW-G235D
Control: IR: LH40 / 50 Ver 1.6
Specifications 42LH4000
LG 42LH4000
General recommendations for repairing TV LCD
Possible manifestations of defects
- LG 42LH4000 does not turn on, the indicators on the front panel do not light or flash. The TV does not respond to the control buttons and the remote control.
Typically, with such manifestations, the defect is caused by faulty elements in the EAX55357701 main power module. It is necessary to measure its output voltages, and in case of their absence (full or partial), it is necessary to check the serviceability of power switches (07N60C3) of converters and rectifier diodes for the presence of a possible short circuit.
In case of breakdowns in the secondary circuits, the converter, as a rule, can emergency work in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse usually 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 STR-W6252, ICE2PCS06 (PFC), in the absence of visible damage or explicit short-circuit between the terminals, are checked by replacing with new ones, or obviously working.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it on and immediately disappears
The defect can be caused by problems in the nodes or elements of the backlight of the display, or in the power supply of the lamps or the inverter.After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, you must ring in its converter power keys for breakdown and secondary windings of transformers for an open.
Sometimes, for diagnostic purposes, inverter protection must be disabled. In such cases, special care must be taken during work, and the protection circuits should be restored immediately after the repair is completed.
- 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 EAX60686904 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). Often, the MB (SSB) card needs to be replaced in case of complex faults that are difficult to detect. When trying to repair, you should check its elements - CPU: LGE3368A-LF-SF, NAND: FLASH: HY27US08121B-TPCB, SPI FLASH: W25X32VSSIG, EEPROM: M24512 and replace the failed chips with new ones. Some malfunctions may be due to the use of BGA soldering technologies in modern Main Board technologies. Typically, such defects are detected by local heating of the chip.
If there is no reception of television channels, but the TV is working properly from external devices, first of all you need to check the power supply of the TDFW-G235D tuner and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Once again, remind users! Attempts to self-repair the LG 42LH4000 TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
SCHEMATIC DIAGRAM ---------> LG 42LH4000 Chassis LD91G
The appearance of the MainBoard EAX60686904 is shown in the figure below:EAX60686904
EAX60686904 can be used in TVs:
LG 32LD320 (Panel T315XW03 V1), LG 32LD320-ZA (Panel T315XW03), LG 32LH4000-ZA (Panel LC320WUN), LG 32LH2000 (Panel LK315T3LA57), LG 32LH2010 (Panel LK315T3LA57), LG 32LF2510 ZB (Panel LC320WUN (SA)(B3)), LG 37LH2000 (Panel LC370WXE (SB)(A1)), LG 19LD320 ZA (Panel M185B1-L02 Rev.C3), LG 26LH2000 (Panel T260XW02 V.R), LG 32LG2100 (Panel LC320WXN), LG 22LH2000 ZA (Panel V216B1-L02), LG 42LH2000 ZA.ARUVLH (Panel LC420WXE (SB)(A1)), LG 32LD321 32LD321-ZB (Panel T315XW03 V1), LG 26LD320 (Panel T260XW04 V.3), LG 19LH2000 19LH2000-ZA (Panel M185B1-L03).
The appearance of the power supply
Main features of the device LG 42LH4000:
Installed matrix (LCD panel) LC420WUH (SB) (A1).
The matrix control uses the Timing Controller (T-CON) EAX58017201.
To power the backlight, a converter is used, combined with the power supply, controlled by the BD9215F PWM controller. The transformer LIF42-001 FLB-2 is installed in the inverter converter.
The necessary supply voltages for all nodes of the LG 42LH4000 TV are generated by the EAX55357701 power supply module or its analogs using STR-W6252, ICE2PCS06 (PFC) microcircuits and power switches of the 07N60C3 type.
MainBoard - the main board (motherboard) is an EAX60686904 module using CPU chips: LGE3368A-LF-SF, NAND: FLASH: HY27US08121B-TPCB, SPI FLASH: W25X32VSSIG, EEPROM: M24512 and others.
The TDFW-G235D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC420WUH-SBA1
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