Technical description and composition of the LG 42LD550 TV, panel type and applicable modules. The composition of the modules.LG
Model: 42LD550 ZC
Chassis / Version: LD01B
Panel: LC420WUG (SC) (A1)
Lamp backlight: 16 LAMP EEFL
Inverter (backlight): integrated into PSU
PWM Inverter: BD9270F
MOSFET Inverter: 2SK3868
Power Supply (PSU): EAX61124201 / 15 REV 1.2
PWM Power: HS01G (PFC), STR-W6053N
MOSFET Power: 2SK3868, 13NM60N
MainBoard: EAX61354204 (0)
IC MainBoard: CPU: LGE107DC, FLASH NAND: H27U1G8F2BTR, DDR3 SDRAM: H5T01G63BFR, Audio amp: NTR-7100
Tuner: TDTJ-S001D
Specifications 42LD550
LG 42LD550
General recommendations for repairing TV LCD
Possible malfunctions
- LG 42LD550 does not turn on and does not show any signs of performance at all. Does not blink indicators and does not respond to control buttons.
Most often, with such manifestations, the main power supply module EAX61124201 is found to be faulty. It is then necessary to measure its output voltages and, if they are absent, you should check the power switches (2SK3868, 13NM60N) and the rectifier diodes of the converters for a short circuit probability.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in emergency short-circuit mode without output voltages, and during short circuit in the elements of the primary circuit, the main fuse and, less often, the current sensor at the source of the key are most often cut off.
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 microchips (PWM) HS01G (PFC), STR-W6053N are usually checked by replacing with new ones, or obviously working.
- There is no image, there is sound, it responds to the remote control. 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.
If in diagnosing a malfunction, it is necessary to disable the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required during work, and after they are finished, it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- 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 EAX61354204 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). When repairing an MB board, you need to check its CPU components: LGE107DC, FLASH NAND: H27U1G8F2BTR, DDR3 SDRAM: H5T01G63BFR, Audio amp: NTR-7100. Defective items should be replaced. If chips with BGA soldering technology are used, a problem in its implementation is detected by the local heating of the chip.
The TDTJ-S001D tuner malfunction 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.
TV users and owners need to remember that attempts to self-repair an LG 42LD550 TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
schematic diagram ------------> LG 42LD550 Chassis LD01B
MODELS ----> 42LD550, 42LD558 -ZC, 42LD551, 42LD559 -ZA, 42LD550N, 42LD550N-ZC.
FIRMWARE SPI FLASH LG 42LD550 ZC LD01B, Main: EAX61354204 (0), Panel: LC420WUG (SC)(A1)
The appearance of the MainBoard EAX61354204 is shown in the figure below:EAX61354204
EAX61354204 can be used in TVs:
LG 32LD345 (Panel LC320WXE-SCA1), LG 37LD450 (Panel LC370WUG (SC)(A1)), LG 42LD455-ZA (Panel LC420WUG), LG 32LD550 (Panel LK315D3LA57), LG 42LD450 ZA (Panel LC420WUG (SC)(A1)), LG LG32LD350 32LD350 (Panel T315HW04 V.8), LG 42LD420 ZA (Panel LC420WUG (SC)(A1)), LG 37LD420 ZA (Panel T370HW03 V.B), LG 32LD420 ZA (Panel LC320WUG (SC)(A1)), LG 32LD555 ZC (Panel LC320WUG (SC)(A1)), LG 26LD355-ZA (Panel T260XW04 V.3), LG 37LD425 ZA (Panel T370HW03 V.B), LG 32LD425 (Panel LC320WUG (SC)(A1)), LG 32LD340 32LD340-ZA.BRUWLJU (Panel LC320WXE (SC)(A1)).
The appearance of the power supply
Main features of the device LG 42LD550:
Installed matrix (LCD panel) LC420WUG (SC) (A1).
To power the backlight, a converter is used, combined with the power supply, controlled by the BD9270F PWM controller. As power elements of the inverter, keys of the 2SK3868 type are used.
The necessary supply voltages for all nodes of the LG 42LD550 TV are generated by the EAX61124201 power module, or its analogs using HS01G (PFC), STR-W6053N microchips and power switches of the 2SK3868, 13NM60N type.
MainBoard - the main board (motherboard) is an EAX61354204 module, using CPU chips: LGE107DC, FLASH NAND: H27U1G8F2BTR, DDR3 SDRAM: H5T01G63BFR, Audio amp: NTR-7100 and others.
The TDTJ-S001D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC420WUG-SCA1
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 (3H)
Brightness: 500 cd / m²
Contrast Ratio: 1450: 1
Display Colors: 16.7M / 1.06B (8-bit / 8-bit + FRC), CIE1931 72%
Response Time: 8/10 (Tr / Td)
Frequency: 60Hz
Lamp Type: 16 pcs EEFL Without Driver
Signal Interface: Mini LVDS, 60 pins
Voltage: 12.0V