Technical description and composition of the LG 42LB570V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 42LB570V
Chassis / Version: LE46B / LD46B
Panel: LC420DUE (FG) (A4)
LED backlight: LG lnnotek DRT 3.0 42_A / B type Rev01 (01.01.01.07) 6916L-1957A
T-CON: 6870C-0480A
LED driver (backlight): integrated into PSU
PWM LED driver: BD9486F
Power Supply (PSU): EAX65423701 (1.9) LGP3942-14PL1
PWM Power: MAP8800 (PFC), FA6A01N (PWM resonant), NR134S
MainBoard: EAX65610904 (1.0), EBR78617401 SAA36861530 SAA36823111
IC MainBoard: EEPROM: 24C256, SOUND: Audio: NTP7513
Tuner: TDJM-G101D EBL61400501
Specifications 42LB570V
LG 42LB570V
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 32CS560 TV does not turn on and does not show any signs of turning on. There are no reactions to the control buttons or the remote control.
In such cases, the EAX65423701 power supply is usually faulty. It is necessary to measure the secondary output voltage, and in case of their absence, check the serviceability of the power switches of the converters and rectifier diodes for a possible short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in short circuit mode, and when a primary circuit is shorted in power elements, the mains fuse usually breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, power supply, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. PWM chip MAP8800 (PFC), FA6A01N (PWM resonant), NR134S can also cause a malfunction of the power switch of the converter and is checked by replacement.
- There is no image, there is sound, it responds to the remote control, the channels are switched. In some cases, the image appears when you turn on and immediately 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.
When diagnosing, it is necessary to take into account that it is impossible to check the open in the chain of LED lines without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally, a current source. By opening the panel, each LED can be checked separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect probes in the forward direction to it. In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as a health indicator. 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 EAX65610904 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). Board repair and chip replacement EEPROM: 24C256, SOUND: Audio: NTP7513 are made with the necessary equipment, and the corresponding hardware base. Faults associated with the application of BGA processor soldering technologies can be localized by the heating method.
Malfunction of the TDJM-G101D EBL61400501 tuner 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 42LB570V TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
Schematic diagram ------------> LG 42LB570V Chassis LE46B/LD46B.
CHASSIS : LD46B; MODEL : 42LB57**, 42LB57**-Z*
Backlight Current Limit:
In televisions with power supplies LGP3942-14PL1 (EAX65423701), the backlight current sensor - the resistor block R811-R818 consists of four pairs of 4.3 Ohm each. You can reduce the backlight current by 25% by removing one pair of resistors.
The appearance of the MainBoard EAX65610904 is shown in the figure below:EAX65610904
EAX65610904 can be used in TVs:
LG 32LB582V ZG (Panel LC320DUE (FG)(A4)), LG 42LB570V (Panel LC420DUE (FG)(A4)), LG 42LB5800 (Panel LC420DUE (P6)(A4)), LG 42LB580V (Panel LC420DUE (FG)(A4)), LG 32LB570U 32LB570U-ZJ (Panel NC320DXN VSBP2), LG 39LB580V (Panel T390HVF02.0 HC390DUN-VCHS1), LG 32LB580V ZB (Panel LC320DUE (FG)(A4)).
The appearance of the power supply
Main features of the device LG 42LB570V:
Installed matrix (LED-panel) LC420DUE (FG) (A4).
The matrix control uses the Timing Controller (T-CON) 6870C-0480A.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the BD9486F PWM controller.
The necessary supply voltages for all nodes of the LG 42LB570V TV are generated by the EAX65423701 power supply module or its analogs using the MAP8800 (PFC), FA6A01N (PWM resonant), NR134S microcircuits.
MainBoard - the main board (motherboard) is an EAX65610904 module, using EEPROM: 24C256, SOUND: Audio: NTP7513 and others.
Tuner TDJM-G101D EBL61400501 provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: LG Display
Model: LC420DUE-FGA4
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
Contrast Ratio: 1200: 1
Display Colors: 16.7M (8-bit), CIE1931 68%
Response Time: 6 (G to G)
Frequency: 60Hz
Lamp Type: WLED Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V