Technical description and composition of the LG 42LW573S TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 42LW573S
Chassis / Version: LD12C
Panel: LC420EUF (SD) (F2)
T-CON: 6870C 0358A V6 32/42/47 FHD 120 Hz
LED driver (backlight): integrated into PSU
PWM LED driver: FAN7930B
Power Supply (PSU): EAX62865401 / 8 EAY62169801
PWM Power: FAN7930B (PFC), 3BR4765JZ (Standby), L6599AD
MainBoard: EAX63686303 (0) EBR73503603
IC MainBoard: LGE35230 / LGE7303C-LF, 24C16WP, 25X20BV
Tuner: TDFR-G256D
Specifications 42LW573S
LG 42LW573S
General repair guidelines for TV LCD LED
Possible manifestations of defects
- LG 42LW573S TV does not turn on, does not respond to the remote control and control panel buttons, indicators do not light up and do not blink.
Usually, with such manifestations, the defect is caused by faulty elements in the EAX62865401 main power module. Then we recommend that you measure its output voltages and, if they are absent, you should check the health of the power switches and rectifier diodes of the converters for a probable short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during a short circuit in the elements of the primary circuit, the mains 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) FAN7930B (PFC), 3BR4765JZ (Standby), L6599AD, 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 commands from the remote control. Or the image appears immediately after turning on and disappears.
As a rule, in such cases there is no display backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to detect a break in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect the probes in the forward direction to it (red probe to the anode, black to the cathode). In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of health. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- The indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the EAX63686303 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). In cases of complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its chips LGE35230 / LGE7303C-LF, 24C16WP, 25X20BV and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
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 TDFR-G256D tuner and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
TV users and owners need to remember that attempts to self-repair an LG 42LW573S TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
SCHEMATIC DIAGRAM -----------> LG 42LW573S Chassis
The appearance of the MainBoard EAX63686303 is shown in the figure below:EAX63686303
The appearance of the power supply
Main features of the device LG 42LW573S:
Installed matrix (LED-panel) LC420EUF (SD) (F2).
The matrix control uses the Timing Controller (T-CON) 6870C.
To power the backlight LEDs, a converter is used, combined with the power supply, controlled by the FAN7930B PWM controller.
The necessary supply voltages for all nodes of the LG 42LW573S TV are generated by the EAX62865401 power module or its analogs using FAN7930B (PFC), 3BR4765JZ (Standby), L6599AD microcircuits.
MainBoard - the main board (motherboard) is an EAX63686303 module, using LGE35230 / LGE7303C-LF, 24C16WP, 25X20BV and other chips.
The TDFR-G256D tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC420EUF-SDF2
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 10%), Hard coating (2H)
Brightness: 400 cd / m²
Contrast Ratio: 1600: 1
Display Colors: 16.7M / 1.06B (8-bit / 8-bit + Dithering), CIE1931 72%
Response Time: 5.5 (Typ.) (G to G); 6 (MPRT)
Frequency: 120Hz
Lamp Type: WLED Without Driver
Signal Interface: LVDS (4 ch, 8/10-bit), 92 pins
Voltage: 12.0V