Technical description and composition of the LG 42LW980S TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 42LW980S
Chassis / Version: LD12D
Panel: LC420EUF (SD) (F2)
T-CON: 6870C-0358A
LED driver (backlight): integrated into PSU
PWM LED driver: FAN7930B
Power Supply (PSU): EAX62865401 / 8
PWM Power: FAN7930B (PFC), 3BR4765JZ (Standby), L6599AD
MainBoard: EAX64294002 (1)
IC MainBoard: LGE7303C-LF, H5TQ1G63DFR, 25X20
Tuner: TDTJ-S001D
Appearance
LG 42LW980S
General repair guidelines for TV LCD LED
Possible malfunctions
- LG 42LW980S TV does not turn on at all. There is no reaction to the remote control and control buttons from the front panel. Indicator lights do not light or flash.
With such manifestations, a malfunction is most likely to be detected in the EAX62865401 power module. It is necessary to measure its output voltages and, in case of their absence, check the serviceability of power switches and rectifier diodes in the converters for possible breakdown.
In case of any breakdown of semiconductors in the secondary circuits, the converter can usually work normally in emergency short circuit mode. There are no output voltages. And with a short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and less often the current sensor at the source of the key.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM chips FAN7930B (PFC), 3BR4765JZ (Standby), L6599AD are usually checked by replacing with new, or obviously working.
- There is no image, there is sound, it is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
As a rule, in such cases there is no display backlight. The reason can be both in the power of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
To detect a break in the LED lines without disassembling the panel, a current source is required. It is impossible to open transitions connected in series with a simple multimeter; voltage of several tens of volts is necessary.
- 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 EAX64294002 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). Sometimes they require checking or replacing (if necessary) the elements of the MainBoard board - LGE7303C-LF, H5TQ1G63DFR, 25X20. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
Before changing the tuner TDTJ-S001D, if it is not possible to tune to television channels, you should make sure that there are supply voltages that must be measured at the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Attention! For users and owners of 42LW980S TVs who do not have the appropriate qualifications, knowledge and experience, we strongly recommend against attempting self-repair in order to avoid negative consequences that could lead to complete non-repairability of the device.
The appearance of the MainBoard EAX64294002 is shown in the figure below:EAX64294002
The appearance of the power supply
Main features of the device LG 42LW980S:
Installed matrix (LED-panel) LC420EUF (SD) (F2).
The matrix control uses the Timing Controller (T-CON) 6870C-0358A.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the FAN7930B PWM controller.
The necessary supply voltages for all nodes of the LG 42LW980S 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 EAX64294002 module using LGE7303C-LF, H5TQ1G63DFR, 25X20 and other chips.
The TDTJ-S001D tuner provides TV 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