Technical description and composition of the LG 42LD450 TV, panel type and applicable modules. The composition of the modules.LG
Model: 42LD450 ZA
Chassis / Version: LD01B
Panel: LC420WUG (SC) (A1)
Inverter (backlight): integrated into PSU
PWM Inverter: BD9270F
Power Supply (PSU): EAX61124201 / 15 REV 1.2
PWM Power: STR-W6053N, HS01G (PFC)
MOSFET Power: 13NM60N, 2SK3868
MainBoard: EAX61354204 (0)
IC MainBoard: NAND Flash: H27U1G8F2BTR; SPI Flash: 25Q80BVSIG; EEPROM: 24C16WP;
Tuner: TDTJ-S001D
Specifications 42LD450
LG 42LD450
General recommendations for repairing TV LCD
Repair of electronic devices, including the LG 42LD450 ZA TV, it is advisable to start with an external examination of its external and internal elements. Specific external damage to some elements can sometimes indicate further actions to determine the malfunction of the TV and localize the defect before the necessary measurements are taken. Experienced repairmen are often aware of the causes of the defect and 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 signs of certain malfunctions.
If the TV does not turn on, no control lights are on or blinking, there are no sounds when you turn on, and there is not the slightest sign of operability - the most likely malfunction is in the power module. First of all, it is necessary to replace the swollen capacitors of the rectifier filters, if any. If the mains fuse is broken in the power supply, in most cases a breakdown of the power key (s) is detected, which can be integrated with the PWM controller, or a separate field-effect transistor can be used. The rectifier bridge diodes and the electrolytic capacitor of the mains rectifier filter should also be checked.
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.
In cases where the LG 42LD450 TV has lost an image, and the sound is there and all the other functions are functional, there is a possibility of a malfunction of the inverter (converter for powering the backlight). When you turn on the TV, the image may appear briefly and immediately disappear. It must be borne in mind that with such manifestations, the lamps themselves also fail, the malfunction of which can be detected by replacement, by connecting to the connectors for diagnostics that are known to be serviceable and suitable in power. If in diagnosing a malfunction, it is necessary to disable the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required during work, and after they are finished, it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
Repair of the EAX61354204 (0) motherboard should begin with the diagnosis and verification of all linear stabilizers and power converters of its microcircuits. Sometimes it may be necessary to update the software (software) - flashing FLASH or EEPROM. In some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - NAND Flash: H27U1G8F2BTR; SPI Flash: 25Q80BVSIG; EEPROM: 24C16WP; to new or obviously serviceable. In cases where BGA technologies are used, defects are usually localized by the heating method.
If there is no reception of television channels, but the TV is working properly from external devices, first of all you need to check the power supply of the TDTJ-S001D tuner and update the software.
Attention! For users and owners of 42LD450 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 42LD450, 42LD450N 42LD450, 42LD450N-ZA, 42LD455, 42LD458, 42LD455-ZA, 42LD458-ZA, 42LD465, 42LD465N 42LD465, 42LD465N-ZA, 42LD468, 42LD468-ZA Chassis LD01B.
PSU schematic diagram ------------> LGP42-10LF EAX61124201 EAY60869402 Power supply
The appearance of the MainBoard EAX61354204 is shown in the figure below:
EAX61354204
EAX61354204 can be used in TVs:
LG 32LD345 (Panel LC320WXE-SCA1), LG 37LD450 (Panel LC370WUG (SC)(A1)), LG 42LD455-ZA (Panel LC420WUG), LG 32LD550 (Panel LK315D3LA57), LG 42LD450 ZA (Panel LC420WUG (SC)(A1)), LG LG32LD350 32LD350 (Panel T315HW04 V.8), LG 42LD420 ZA (Panel LC420WUG (SC)(A1)), LG 37LD420 ZA (Panel T370HW03 V.B), LG 32LD420 ZA (Panel LC320WUG (SC)(A1)), LG 32LD555 ZC (Panel LC320WUG (SC)(A1)), LG 26LD355-ZA (Panel T260XW04 V.3), LG 37LD425 ZA (Panel T370HW03 V.B), LG 32LD425 (Panel LC320WUG (SC)(A1)), LG 32LD340 32LD340-ZA.BRUWLJU (Panel LC320WXE (SC)(A1)).
PSU Advanced
On the 42LD450 TV, the EAX61124201 / 15 REV 1.2 power module is installed using the PFC (Power Factor Correction) scheme acting as an active filter to eliminate the higher harmonic components of the current consumption. The step-up converter based on the HS01G PWM controller does not allow the input rectifier filter's electrolytic capacitor to be connected to the network directly through open diodes when the charge current is determined by its reactance (of the order of 15-30 ohms at a frequency of 50 Hz). As a result of the conversion, the charging current of the capacitor will be determined in such a way that the envelope of the high-frequency pulses of the input current will repeat the phase and shape of the sine wave of the input voltage. The health check of the PFC unit is carried out by measuring the DC voltage on the capacitor of the rectifier network. In operating mode, it should be around 380V, in standby approximately 300V.
The appearance of the power supply
Main features of the device LG 42LD450:
Installed matrix (LCD panel) LC420WUG (SC) (A1).
To power the backlight, a converter is used, combined with the power supply, controlled by the BD9270F PWM controller.
The necessary supply voltages for all nodes of the LG 42LD450 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 EAX61354204 module, using NAND Flash chips: H27U1G8F2BTR; SPI Flash: 25Q80BVSIG; EEPROM: 24C16WP; and others.
The TDTJ-S001D tuner provides TV reception and channel tuning.
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