Technical description and composition of the LG 42LF2510 TV, panel type and applicable modules. The composition of the modules.LG
Model: 42LF2510
Chassis / Version: LD91A
Panel: LC420WUE (SB) (C1)
T-CON: 6870C-0243C
Inverter (backlight): integrated into PSU
PWM Inverter: BD9275F
Trans Inverter: LIF42-001 FLB-2
Power Supply (PSU): EAX55357701 / 32
PWM Power: STR-W6252, ICE2PCS06 (PFC)
MOSFET Power: 07N60C3
MainBoard: EAX60686902 (0) - EBU60710812, SAA34326013 Ver 3.24, SAA34419901 Ver 3.00
IC MainBoard: CPU: LGE3368A-LF-SF; RAM: HY5PS1G1631C; SPI FLASH: Winb25X32VSIG; AUDIO: NTP-3100L
Tuner: TDFW-G235D
Control: IR EBR48885611, EAX44059405 (0)
Specifications 42LF2510
LG 42LF2510
General recommendations for repairing TV LCD
Repair and diagnostics of any electronic device, in particular LG 42LF2510, it is advisable to start with a careful external examination of internal and external elements. Often, based on certain external signs, it may be possible to draw certain conclusions about the reasons for the failure of certain elements of the circuit even before the necessary measurements are made, which will determine the further algorithm for troubleshooting and localizing the defect. If ring cracks are detected in the soldering of the terminals of the elements or dangling connecting tracks, swollen capacitors or charred resistors - all this can be characteristic signs of the causes or consequences of an already known typical malfunction.
If the TV does not turn on, no indicators on its front panel are lit or blinking. Also, if the TV does not respond to the remote control and buttons, does not make any sounds or any signs of operability when turned on, there is a certain chance that the EAX55357701 / 32 power supply module is defective and needs repair. Sometimes with similar manifestations a problem can only occur in the absence of standby power. Diagnostics and repair of the common power supply should always begin with a check of the mains fuse and the condition of the electrolytic capacitors of the secondary rectifier filters. Defective and swollen capacitors should be replaced with new ones. If the fuse breaks, it is advisable to check for a breakdown, first of all, all power semiconductor elements of the converter and the diode bridge of the rectifier network, as well as a large electrolytic capacitor of the filter of the rectifier network.
Mos-Fet keys used in switching power supplies (SMPS) rarely fail for no reason to look for when checking other circuit elements. Often the breakdown is caused by malfunctions of electrolytic capacitors or semiconductor elements in the primary circuit, or by a break in the resistors in the stabilization circuits. The PWM controller chip can also cause a breakdown of the power switch of the converter.
If the LG 42LF2510 does not have an image, there is sound and the channels are switched, there is a possibility of a malfunction of the display backlight, or their power converter - inverter. 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 inverter itself, including in the secondary rectifier of the main PSU. When disabling protection in order to enable the diagnosis of a malfunction, special care should be taken, and after completion of all repair work, it is necessary to restore the circuit and the inverter protection for further safe operation of the TV.
If the motherboard EAX60686902 (0) is faulty - EBU60710812, SAA34326013 Ver 3.24, SAA34419901 Ver 3.00, first of all it is necessary to check all the linear stabilizers and power converters of its chips, and also, if necessary, update the software (software). Sometimes you can check the health of MB only by replacement. Board repair and replacement of CPU chips: LGE3368A-LF-SF; RAM: HY5PS1G1631C; SPI FLASH: Winb25X32VSIG; AUDIO: NTP-3100L are produced with the necessary equipment, and the corresponding element base. Faults associated with the application of BGA processor soldering technologies can be localized by the heating method.
Before changing the TDFW-G235D tuner, if it is not possible to tune to television channels, make sure that there are supply voltages that must be measured at the corresponding tuner terminals and checked for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Attention! For users and owners of 42LF2510 TVs who do not have the appropriate qualifications, knowledge and experience, we categorically do not recommend attempting self-repair in order to avoid negative consequences that could lead to complete non-repairability of the device.
SCHEMATIC DIAGRAM ---------> LG CHASSIS LD91A; 32LF2500, 32LF2500-ZA, 32LF2510, 32LF2510-ZB
The appearance of the MainBoard EAX60686902 is shown in the figure below:EAX60686902
EAX60686902 can be used in TVs:
LG 37LH3000 (Panel T370HW02 V.G), LG 32LH2000 (Panel LK315T3LA57), LG 32LF2510 ZB (Panel LC320WUN (SA)(B3)), LG 42LF2510 (Panel LC420WUE (SB)(C1)), LG 47LH3000 (Panel LC470WUE), LG 32LH3010 (Panel LC320WUN (SA)(B2)), LG 37LH2010 37LH2010-ZB.BRUVLJU (Panel LC370WXE (SB)(A1)).
PSU Advanced
According to the conditions of compliance with modern world standards for household switching power supplies, the EAX55357701 / 32 module provides for the use of a Power Factor Correction unit. The PFC circuit is a flyback converter based on the ICE2PCS06 PWM controller. The reactance of an electrolytic capacitor of a line filter at a frequency of 50-60 Hz is usually not more than 20-30 ohms and its charge directly from the network through open diodes could reach tens of amperes per pulse if no filtering were applied.
As a result of the PFC conversion, an increased voltage on the capacitor (about 380V) cannot directly open the rectifier diodes, on the anode of which the voltage will always be slightly less (about 300V) and then its charging current will always be limited by the elements of the PWM controller. As a result, the envelope of the high-frequency pulses of the consumed current will repeat the shape and phase of the input sinusoidal voltage. The presence of an increased voltage (+ 380V) on the network capacitor indicates the serviceability of the PFC node.
The appearance of the power supply
Main features of the device LG 42LF2510:
Installed matrix (LCD panel) LC420WUE (SB) (C1).
The matrix control uses the Timing Controller (T-CON) 6870C-0243C.
To power the backlight, a converter is used, combined with a power supply, controlled by a BD9275F PWM controller. The transformer LIF42-001 FLB-2 is installed in the inverter converter.
The necessary supply voltages for all nodes of the LG 42LF2510 TV are generated by the EAX55357701 power module or its analogs using STR-W6252, ICE2PCS06 (PFC) microcircuits and 07N60C3 type power switches.
MainBoard - the main board (motherboard) is an EAX60686902 module using CPU chips: LGE3368A-LF-SF; RAM: HY5PS1G1631C; SPI FLASH: Winb25X32VSIG; AUDIO: NTP-3100L and others.
The TDFW-G235D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC420WUE-SBC1
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: 1400: 1
Display Colors: 16.7M / 1.06B (8-bit / 8-bit + FRC)
Response Time: 5 (G to G)
Frequency: 60Hz
Lamp Type: 18 pcs EEFL Without Driver
Signal Interface: LVDS (2 ch, 8/10-bit), 51 pins
Voltage: 12.0V