Technical description and composition of the LG 42LB679V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 42LB679V
Chassis / Version: LD42B
Panel: LC420DUH (PG) (F1)
LED backlight: 42 V14 Slim DRT Rev0.6 1 L1-Type x3pcs, L2-Type x2pcs, R1-Type x3pcs, R2-Type x2pcs, 45LED's 2.67V, 15 channels x3LED's
T-CON: integrated into Panel
LED driver (backlight): integrated into PSU
PWM LED driver: iW7025-00
Power Supply (PSU): EAX65424001 (2.2) - LGP42-14LPB
PWM Power: NCP1034DG, MAP8800 (PFC), ICE3BR4765JZ
MOSFET Power: 13N60M2
MainBoard: EAX65384004 (1.5)
IC MainBoard: CPU: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR
Tuner: TDJM-G101D
Specifications 42LB679V
LG 42LB679V
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The LG 42LB679V TV does not turn on at all. The control lights do not light or flash. The TV on the remote control and the control panel buttons do not respond.
In such cases, the malfunction should be sought first in the EAX65424001 power supply module. Then we recommend that you measure its output voltages and, if they are absent, you should check the health of the power switches (13N60M2) and rectifier diodes of the converters for possible 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 main fuse usually breaks.
Breakdown of power switches (MosFet) in pulsed sources is sometimes caused by malfunctions of other circuit elements, for example, in circuits supplying a PWM controller, frequency-setting or damper ones, as well as in negative feedback (OOS) stabilization circuits. PWM controllers (PWM) NCP1034DG, MAP8800 (PFC), ICE3BR4765JZ, if they do not have visible damage to the case and open fault between the terminals, are usually checked by replacement.
- There is no image, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
Usually in such cases, a malfunction is detected in the backlight nodes of the LED panel. The reason can be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
When trying to detect a break in the LED lines, it should be taken into account that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the EAX65384004 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 must be replaced in case of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - CPU: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR and failed chips replace 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.
Malfunction of the tuner TDJM-G101D 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.
Attention to users! Self-repair of the LG 42LB679V TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
schematic diagram ------------> LG CHASSIS: LD42B MODEL : 42LB67**, 42LB67**-Z*
The appearance of the MainBoard EAX65384004 is shown in the figure below:EAX65384004
EAX65384004 can be used in TVs:
LG 32LB650V ZE (Panel LC320DUH (FG)(P2)), LG 47LB650V ZE (Panel LC470DUH (FG) (P2)), LG 42LB650V (Panel LC420DUH (FG)(P2)), LG 42LB671V ZF (Panel LC420DUH (PG) (F1)), LG 47LB671V (Panel LC470DUH (PG)(F1)), LG 42LB653V ZK (Panel LC420DUH (FG)(P1)), LG 42LB720V (Panel LC420DUH (PG)(F1)), LG 42LB658V (Panel LC420DUH (FG)(P2)), LG 47LB677V (Panel LC470DUH (FG)(F1)), LG 42LB679V (Panel LC420DUH (PG)(F1)), LG 47LB653V (Panel LC470DUH (FG)(P1)), LG 32LB653V (Panel LC320DUH( FG)(P1)), LG 42LB690V (Panel LC420DUH (PG)(F1)), LG 55LB630V (Panel LC550DUH).
The appearance of the power supply
Main features of the device LG 42LB679V:
Installed matrix (LED-panel) LC420DUH (PG) (F1).
The matrix control uses the Timing Controller (T-CON) integrated.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the iW7025-00 PWM controller.
The necessary supply voltages for all nodes of the LG 42LB679V TV are generated by the EAX65424001 power module or its analogs using NCP1034DG, MAP8800 (PFC), ICE3BR4765JZ microcircuits and 13N60M2 type power switches.
MainBoard - the main board (motherboard) is an EAX65384004 module, using CPU chips: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR and others.
The TDJM-G101D tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC420DUH-PGF1
Type: a-Si TFT-LCD, Panel
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: IPS, Normally Black, Transmissive
Active Area: 927.94x521.96 mm
Surface: Antiglare (Haze 1%), Hard coating (3H)
Brightness: 400 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 1.06B (10-bit), CIE1931 72%
Response Time: 8/10 (Tr / Td)
Frequency: 120Hz
Lamp Type: WLED Without Driver
Signal Interface: EPI, 100 pins
Voltage: 12.0V