Technical description and composition of the LG 42LC51-ZA TV, panel type and applicable modules. The composition of the modules.LG
Model: 42LC51-ZA
Chassis / Version: LP78A
Panel: LC420WX8 (SL) (A1)
Lamp backlight: 18 Lamp EEFL
Inverter (backlight): EAY34797001 PLHL-T604A
PWM Inverter: FAN7382
MOSFET Inverter: SD20N60
Power Supply (PSU): EAX32268301 / 9 PLHL-T604A EAY34797001
PWM Power: 5501A, ICE3B1565J, FAN7601
MOSFET Power: 04N60C3
MainBoard: EAX32572506 (0) EBR35513001
IC MainBoard: ANX9021, TPA3107D2, STMAV340, VCT7993P, AMTEL7044C32AN, TEA6420, MP2355DN
Tuner: TAFT-W005D
Specifications 42LC51
LG 42LC51-ZA
General recommendations for repairing TV LCD
Possible manifestations of defects
- The LG 42LC51-ZA 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.
Often in such cases, the EAX32268301 power module is faulty. It is necessary to measure its output voltages, and in case of their absence (full or partial), it is necessary to check the serviceability of power switches (04N60C3) of converters and rectifier diodes for the presence of a possible short circuit.
In case of breakdowns of semiconductors in secondary circuits, the converter can usually operate abnormally in short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse often breaks.
Mos-Fet power switches, used in switching power supplies, sometimes fail due to a malfunction of any other elements that can put it out of operation in key mode or create an excess of the maximum permissible parameters of the switch. These can be elements supplying the PWM controller, frequency-setting or damping circuits, or negative feedback elements in the stabilization circuit. PWM controllers 5501A, ICE3B1565J, FAN7601, in the absence of visible damage or explicit short-circuit between the terminals, are checked by replacing with new ones, or obviously working.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it 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 their completion it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- The TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the EAX32572506 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). Complex repair of MB (SSB) is possible only in the conditions of a service center with the necessary equipment. Checking or replacing elements ANX9021, TPA3107D2, STMAV340, VCT7993P, AMTEL7044C32AN, TEA6420, MP2355DN requires the necessary training and professional skills in repairing modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by warming up.
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 voltage of the TAFT-W005D tuner and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Attention TV owners! Self-repair attempts by LG 42LC51-ZA are not recommended by the manufacturer and can lead to serious negative consequences!
schematic diagram ------------> LG 42LC51, 42LC51-ZA Chassis LP78A
The appearance of the MainBoard EAX32572506 is shown in the figure below:EAX32572506
EAX32572506 can be used in TVs:
LG 32LC43-ZE (Panel LC320WX6 SL A3), LG 32LC7RC TA (Panel LC320WX6 (SL)(A3)), LG 32LC41 (Panel LC320WX4 (SL)(D2)), LG 37LC41 ZA (Panel LC370WX4-SLA1).
The appearance of the power supply
Main features of the device LG 42LC51-ZA:
Installed matrix (LCD panel) LC420WX8 (SL) (A1).
To power the backlight, an inverter EAY34797001 is used, it is controlled by the FAN7382 PWM controller. As power elements of the inverter, keys of the type SD20N60 are used.
The necessary supply voltages for all nodes of the LG 42LC51-ZA TV are generated by the EAX32268301 power module, or its analogs using 5501A, ICE3B1565J, FAN7601 chips and 04N60C3 type power switches.
MainBoard - the main board (motherboard) is an EAX32572506 module, using ANX9021, TPA3107D2, STMAV340, VCT7993P, AMTEL7044C32AN, TEA6420, MP2355DN, and others microcircuits.
The TAFT-W005D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG.Philips LCD
Model: LC420WX8-SLA1
Type: a-Si TFT-LCD, Panel
Diagonal size: 42 inch
Resolution: 1366x768, WXGA
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 930.25x523.01 mm
Surface: Antiglare (Haze 13%), Hard coating (3H)
Brightness: 500 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit), CIE1931 73%
Response Time: 5 (G to G); 10 (Tr + Td)
Frequency: 60Hz
Lamp Type: 18 pcs EEFL Without Driver
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V