Friday, 28 February 2020

REPAIR / SERVICING TV LG 42LS5620

Technical description and composition of the LG 42LS5620 TV, panel type and applicable modules. The composition of the modules.
LG
Model: 42LS5620
Chassis / Version: LD21B-LC21B
Panel: T420HVN01.1
T-CON: T315HW07 VB CTRL BD 31T14-C0J
Inverter (backlight): V341-001 V341-002 V341-003 V341-004 V341-005
PWM Inverter: DF3421
Power Supply (PSU): EAX64427001 (1.4) EAY62608801
PWM Power: FAN7930BMX (PFC), ICE3BR4765JZ (Standby DIP-7), L6599AD
MOSFET Power: STD10NM60N (PFC), STD7NM60N
MainBoard: EAX64317403 (1.0) EBR75149802
IC MainBoard: CPU: LGE2111A-T8, Nand: NAND01GW3B2CN6E, DDR: H5TQ1G63DFR-H9C, SPI Flash: W25Q80BV
Tuner: EBL610801 TDSQ-G001D
Specifications 42LS5620
LG 42LS5620
General recommendations for repairing TV LCD
Possible manifestations of defects
- The LG 42LS5620 TV does not turn on and does not show any signs of operability. There is no reaction to either the remote control or the control buttons from the front panel.
With such manifestations, in most cases, the EAX64427001 power module is faulty. It is necessary to measure the secondary output voltage, and in case of their absence, check the serviceability of the power switches (STD10NM60N (PFC), STD7NM60N) of the converters and rectifier diodes for a short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during short circuit in the elements of the primary circuit, the mains fuse usually breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, power supply, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. PWM chip FAN7930BMX (PFC), ICE3BR4765JZ (Standby DIP-7), L6599AD can also cause a malfunction of the power switch of the converter and is checked by replacement.
- There is no image, there is sound, it responds to the remote. Or the image may appear for a second when turned 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 inverter. If all the electrolytic capacitors of the filter according to the power supply of the inverter are working, make sure that the lamps are working, then you need to check the converter keys and the secondary windings of the transformers.
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 turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the EAX64317403 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 CPU chips: LGE2111A-T8, Nand: NAND01GW3B2CN6E, DDR: H5TQ1G63DFR-H9C, SPI Flash: W25Q80BV are made 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.
If you suspect a malfunction of the EBL610801 TDSQ-G001D tuner, first of all, you need to verify the correctness of the software, as well as the presence of the necessary power supply voltage levels and data exchange pulses with the processor via the I2C bus on the corresponding tuner pins.
Attention TV owners! Attempts at self-repair of LG 42LS5620 are not recommended by the manufacturer and can lead to serious negative consequences!


 SCHEMATIC DIAGRAM ---------->  LG LG CHASSIS LD21B; 42LS5600, 42LS560S, 42LS560T, 42LS5610, 42LS561T, 42LS5620 SERVICE MANUAL.


 PSU SCHEMATIC DIAGRAM ---------->  LGP42L-12P EAX64427001 EAY62608801



 The appearance of the MainBoard EAX64317403 is shown in the figure below:
EAX64317403
EAX64317403 can be used in TVs:
LG 32LM580S (Panel LC320EUN (SE)(F2)), LG 32LS5610 (Panel T320HVN01.0), LG 42LM580S ZA (Panel LC420EUE (SE)(F1)), LG 42LS5620 (Panel T420HVN01.1), LG 32LS5600 (Panel T320HVN01.0), LG 42LM585S -ZD (Panel LC420EUE (SE)(F1)).
The appearance of the power supply
Main features of the device LG 42LS5620:
The matrix (LCD panel) T420HVN01.1 is installed.
The matrix control uses the Timing Controller (T-CON) T315HW07.
To power the backlight, an inverter V341-001 is used, it is controlled by the PWM controller DF3421.
The necessary supply voltages for all nodes of the LG 42LS5620 TV are generated by the EAX64427001 power module or its analogs using FAN7930BMX (PFC), ICE3BR4765JZ (Standby DIP-7), L6599AD microchips and power switches of the STD10NM60N (PFC), STD7NM60N type.
MainBoard - the main board (motherboard) is an EAX64317403 module using CPU chips: LGE2111A-T8, Nand: NAND01GW3B2CN6E, DDR: H5TQ1G63DFR-H9C, SPI Flash: W25Q80BV and others.
The tuner EBL610801 TDSQ-G001D provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: AUO
Model: T420HVN01.1 CELL
Type: a-Si TFT-LCD, CELL
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: AMVA3, Normally Black
Active Area: 930.24x523.26 mm
Surface: Antiglare (Haze 2%), Hard coating (3H)
Glass Depth: 0.50 + 0.50 mm
Transmissivity: 5.7% (with Polarizer)
Contrast Ratio: 3000
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 6.5 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V