Technical description and composition of the LG 42LB730V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 42LB730V ZA
Chassis / Version: LD42B
Panel: LC470DUH (PG) (F1)
LED backlight: 6920L-0504A, 6920L-0505A, 6920L-0506A, 6920L-0507A
LED driver (backlight): integrated into PSU
PWM LED driver: iW7025-00
Power Supply (PSU): EAX65424001 LGP42-14LPB
PWM Power: CP1034DG, MAP8800 (PFC), ICE3BR4765JZ
MOSFET Power: 13N60M2
MainBoard: EAX65384004 (1.4) EBR78599402
IC MainBoard: CPU: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR
Tuner: TDJM-G101D
Specifications 42LB730V
LG 42LB730V
General repair guidelines for TV LCD LED
Possible manifestations of defects
- LG 42LB730V 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.
In such cases, the EAX65424001 power supply is usually faulty. It is necessary to measure its output supply voltages, and in case of their absence, check the serviceability of the power switches (13N60M2) of the converters and rectifier diodes for the possibility of breakdown in PN semiconductor junctions.
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.
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 CP1034DG, MAP8800 (PFC), ICE3BR4765JZ, 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
In some of these cases, the malfunction is caused by a lack of backlighting on the display. 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 EAX65384004 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). If it is not possible to replace the MB (SSB) card, you must check the health of its elements - CPU: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR. Defective components should be replaced.
If the TV works normally with external devices, but does not tune into television channels, the TDJM-G101D may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Attention to users! Self-repair of the LG 42LB730V TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
schematic diagram ------------> LG 42LB730V Chassis LD42B
The appearance of the MainBoard EAX65384004 is shown in the figure below:EAX65384004
EAX65384004 can be used in TVs:
LG 32LB650V ZE (Panel LC320DUH (FG)(P2)), LG 47LB650V ZE (Panel LC470DUH (FG) (P2)), LG 42LB650V (Panel LC420DUH (FG)(P2)), LG 42LB671V ZF (Panel LC420DUH (PG) (F1)), LG 47LB671V (Panel LC470DUH (PG)(F1)), LG 42LB653V ZK (Panel LC420DUH (FG)(P1)), LG 42LB720V (Panel LC420DUH (PG)(F1)), LG 42LB658V (Panel LC420DUH (FG)(P2)), LG 47LB677V (Panel LC470DUH (FG)(F1)), LG 42LB679V (Panel LC420DUH (PG)(F1)), LG 47LB653V (Panel LC470DUH (FG)(P1)), LG 32LB653V (Panel LC320DUH( FG)(P1)), LG 42LB690V (Panel LC420DUH (PG)(F1)), LG 55LB630V (Panel LC550DUH).
The appearance of the power supply
Main features of the device LG 42LB730V:
Installed matrix (LED-panel) LC470DUH (PG) (F1).
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the iW7025-00 PWM controller.
The necessary supply voltages for all nodes of the LG 42LB730V TV are generated by the EAX65424001 power supply module or its analogs using CP1034DG, MAP8800 (PFC), ICE3BR4765JZ microcircuits and 13N60M2 type power switches.
MainBoard - the main board (motherboard) is an EAX65384004 module, using CPU chips: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR and others.
The TDJM-G101D tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC470DUH-PGF1
Type: a-Si TFT-LCD, Panel
Diagonal size: 47 inch
Resolution: 1920x1080, FHD
Display Mode: IPS, Normally Black, Transmissive
Active Area: 1039.68x584.82 mm
Surface: Antiglare (Haze 1%), Hard coating (2H)
Brightness: 400 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 1.06B (8-bit + Dithering), CIE1931 72%
Response Time: 8/10 (Tr / Td)
Frequency: 120Hz
Lamp Type: WLED Without Driver
Signal Interface: EPI, 100 pins
Voltage: 12.0V