Technical description and composition of the LG 42LW575S TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 42LW575S
Chassis / Version: PL12C // LD12C
Panel: LC420EUF (SP) (PX) L // LC420EUF (SD) (F2)
LED driver (backlight): 2AXV3 peopleworks
Power Supply (PSU): EAX62865401 / 8 LGP4247-115P // LGP4247-115LPB
PWM Power: AN7930B (PFC), 3BR4765JZ (Standby), L6599AD
MainBoard: EAX64405501
IC MainBoard: CPU: LGE35230, Nand: TC58DVG3S0ETA, DDR: K4B2G1646C
Tuner: TDFQ-G031D
Specifications 42LW575S
LG 42LW575S
General repair guidelines for TV LCD LED
Repair of the LG 42LW575S TV should begin with a fault diagnosis, which involves a careful inspection of the external and internal elements of the device. Visible damage to elements can sometimes indicate the direction of the search for a defect even before the necessary measurements are taken. Experienced repairmen are often aware of the causes of the defect and the possible consequences, for example, from ring cracks in the soldering of the leads of the elements, as well as from swollen capacitors or resistors burnt to coal dust and other external indirect signs.
In cases where the LG 42LW575S TV does not turn on, does not respond to the remote control and buttons, no indicators on the front panel are lit or blinking, and there are no sounds and no signs of operability when turning on, the LCP4247-115P power supply module is most likely faulty or missing processor power on the motherboard (a typical defect of some LG TVs). In the absence of swollen filter capacitors of the secondary rectifiers, the diagnostics of the power supply should be started by checking the fuse and, if it is broken, it is first necessary to check all the power semiconductor elements of the primary circuit - diodes and transistors for the possibility of an avalanche or thermal breakdown.
As a rule, the keys in switching power supplies (SMPS) are reliable enough and rarely fail for no reason to be looked for by checking other components of the circuit - electrolytic capacitors, resistors and semiconductor elements of the primary circuit. The PWM chip is verified by replacing it with a known good one.
If the LG 42LW575S has no image, there is sound and the channels are switched, there is a possibility of a malfunction in the backlight LED circuit of the LC420EUF (SP) (PX) L panel, or their power converter - LED driver. Sometimes when you turn on the image appears and disappears immediately. In such cases, it is necessary to check the electrolytic capacitors of the power filter of the LED driver itself, including in the secondary rectifier of the main PSU.
Often in the absence of backlighting, disassembling the panel is required. It is necessary to check the serviceability of the transitions of the LEDs, as well as the reliability of the contact connections in the rulers and connectors.
When trying to detect a break in the LED lines, it should be taken into account that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.
Diagnosis and repair of the EAX64405501 motherboard is carried out by checking the operability of the stabilizers or power converters of the module chips. In some cases, a software update is required.
If there is no reception of television channels, but the TV is working properly from external devices, first of all it is necessary to check the voltage of the varicaps of the tuner TDFQ-G031D, which is usually within 30-33V, as well as other supply voltages at the terminals of the tuner.
Owners and users of the LG 42LW575S TV must remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!
SCHEMATIC DIAGRAM -----------> LG 42LW570G/570S/575S/579S, 42LW570G/570S/579S-ZD, 42LW575S-ZC, 42LW573S 42LW573S-ZG Chassis LD12C
The appearance of the MainBoard EAX64405501 is shown in the figure below:EAX64405501
EAX64405501 can be used in TVs:
LG 42LW575S (Panel LC420EUF (SP)(PX) L), LG 32LW575S (Panel LC320EUD (SD)(P1)), LG 47LW575S (Panel LC470EUF (SD)(P1)), LG 47LW650S 47LW650S-ZC (Panel LC470EUF (SD)(F1) ).
The appearance of the power supply
Main features of the device LG 42LW575S:
Installed matrix (LED-panel) LC420EUF (SP) (PX) L or LC420EUF (SD) (F2).
To power the backlight LEDs, the 2AXV3 LED driver is used.
The necessary supply voltages for all nodes of the LG 42LW575S TV are generated by the EAX62865401 power module or its analogs using AN7930B (PFC), 3BR4765JZ (Standby), L6599AD microcircuits.
MainBoard - the main board (motherboard) is an EAX64405501 module using CPU chips: LGE35230, Nand: TC58DVG3S0ETA, DDR: K4B2G1646C and others.
The TDFQ-G031D tuner provides television reception and channel tuning.