Technical description and composition of the LG 42LD650 TV, panel type and applicable modules. The composition of the modules.LG
Model: 42LD650 ZC
Chassis / Version: LD03B
Panel: LC420WUG (SC) (A1)
Inverter (backlight): integrated into PSU
PWM Inverter: BD9270F (24 pin)
MOSFET Inverter: 2SK3868
Power Supply (PSU): EAX61124201 / 14 REV1.1 LGP42-10LF
PWM Power: STR-W6053N, HS01G (PFC)
MOSFET Power: 13NM60N, 2SK3868
MainBoard: EAX61531904 EBR67347301
IC MainBoard: CPU: LGE3556C; DRAM: NT5TU128M8DE; SPI Flash: MX25L4005CM2I-12G; SOUND: EAN60969601
Tuner: TDFR-G135D EBL60740401
Specifications 42LD650
LG 42LD650
General recommendations for repairing TV LCD
Repair of electronic devices, including the LG 42LD650 ZC TV, it is advisable to start with an external examination of its external and internal elements. A visible physical change in some components can sometimes suggest a further troubleshooting direction. Ring cracks in the soldering of the leads of the heating elements, swollen electrolytic capacitors, a charred paint layer on the resistors - all this for the repairman can be a significant clue in the assumptions about the causes and consequences of the malfunction.
In the case when the 42LD650 does not turn on, does not respond to the remote control and the front panel buttons, does not blink light bulbs and does not show any signs of operability, the EAX61124201 / 14 REV1.1 LGP42-10LF power supply module is probably faulty in this case. In the general case, first of all, it is necessary to check the electrolytic capacitors of the secondary rectifier filters and the fuse at the input of the network. If it is cut off, then it is necessary to check the diodes of the rectifier bridge and the key transistor of the converter for a breakdown of the PN junctions, which can either be on a separate radiator or integrated with a PWM controller in a common chip. Possible options.
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 42LD650 does not have an image, but there is sound and the TV is controlled by the remote control, a malfunction in the display backlight nodes is likely. The lamps or the power converter - inverter may be faulty. Often in such cases, when you turn on the TV, an image appears and immediately disappears. First of all, it is necessary to verify the operability of the electrolytic capacitors of the rectifier filter supplying the inverter, and check the LCD lamps by connecting external and obviously serviceable for diagnosis to the connectors. When disabling protection for diagnostic purposes, it must be remembered that in this case there is a risk of failure of the power elements of the inverter. Upon completion of the diagnosis, all regular protection circuits should be restored.
Diagnosis and repair of the EAX61531904 EBR67347301 motherboard usually begins with a test of the performance of the stabilizers and power converters of the module chips. In some cases, a software update is required. When repairing an MB board, you need to check its CPU components: LGE3556C; DRAM: NT5TU128M8DE; SPI Flash: MX25L4005CM2I-12G; SOUND: EAN60969601. Defective items should be replaced. If chips with BGA soldering technology are used, a problem in its implementation is detected by the local heating of the chip.
In the absence of tuning to the channels of on-air or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltage at the terminals of the TDFR-G135D EBL60740401 tuner. It is also necessary to check the presence of pulses of data exchange between the tuner and the processor via the I2C bus using an oscilloscope.
Typical defects of LG TVs with LGE3556C processors are provoked by its severe temperature conditions and the quality of the LGE3556C processor itself.It is necessary to remember to users that attempts to self-repair a LG 42LD650 TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
External manifestations may be different - the tuner or external inputs do not work, or the TV does not turn on, for example, the control lamp blinks or hangs on the screen saver.
If, when the processor warms up, performance is restored, in such cases a reball can sometimes help. Then there is the opportunity to extend the life of the TV with the help of an additional heat sink or cooler. When replacing the processor, it should be borne in mind that they are discontinued and all LGE3556C, which sellers ALIexpress send, in most cases control units, are often already faulty.
schematic diagram ------------> LG CHASSIS: LD03B, MODEL: 42LD650/680, 42LD650/680-ZC, 42LD650N/690, 42LD650N/690-ZC, 42LD651/690 42LD651/690-ZB.
PSU schematic diagram ------------> LGP42-10LF EAX61124201 EAY60869402 Power supply
The appearance of the MainBoard EAX61531904 is shown in the figure below:EAX61531904
EAX61531904 can be used in TVs:
LG 42LD750 (Panel LC420WUH (SC)(M1)), LG 42LD650 ZC (Panel LC420WUG (SC)(A1)).
PSU Advanced
The 42LD650 model uses the EAX61124201 / 14 REV1.1 LGP42-10LF power supply unit using the PFC (Power Factor Correction) node - an active filter of higher harmonics of the consumed current. In fact, it is a step-up converter based on the HS01G PWM controller, which eliminates the charge current of the electrolytic capacitor of the rectifier filter directly from the network through open diodes when its charging current is determined by its reactance.
As a result of the operation of the converter, the envelope of the high-frequency pulses of the input current of the converter will repeat the shape and phase of the input voltage. The health of the PFC node can be indirectly judged by the presence of an increased constant voltage (about + 380V) on the capacitor of the rectifier network in operating mode.
The appearance of the power supply
Main features of the device LG 42LD650:
Installed matrix (LCD panel) LC420WUG (SC) (A1).
To power the backlight, a converter is used, combined with a power supply, controlled by a BD9270F PWM controller (24 pin). As power elements of the inverter, keys of the 2SK3868 type are used.
The necessary supply voltages for all nodes of the LG 42LD650 TV are generated by the EAX61124201 power supply module or its analogs using STR-W6053N, HS01G (PFC) microcircuits and 13NM60N, 2SK3868 power switches.
MainBoard - the main board (motherboard) is an EAX61531904 module, using CPU chips: LGE3556C; DRAM: NT5TU128M8DE; SPI Flash: MX25L4005CM2I-12G; SOUND: EAN60969601 and others.
Tuner TDFR-G135D EBL60740401 provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: LG Display
Model: LC420WUG-SCA1
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: 1450: 1
Display Colors: 16.7M / 1.06B (8-bit / 8-bit + FRC), CIE1931 72%
Response Time: 8/10 (Tr / Td)
Frequency: 60Hz
Lamp Type: 16 pcs EEFL Without Driver
Signal Interface: Mini LVDS, 60 pins
Voltage: 12.0V