Saturday 29 February 2020

REPAIR / SERVICING TV LG 42LW4500

Technical description and composition of the LG 42LW4500 TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 42LW4500 ZB
Chassis / Version: LD01U
Panel: LC420EUF (SD) (PX) // LC420EUF (SD) (F2)
LED backlight: 3660L-0374A11, 42 V6 Edge FHD REV1.0 1 L-Type / R-Type
T-CON: T-CON: 6870C-0358A; TPS65168, LG5820, TPS65194, BUF08630, 432RP
LED driver (backlight): PPW-LE42GD-0 (A) Rev 0.5 6917L-0061G
PWM LED driver: SW5508, SW5026
MOSFET LED driver: FDD850N10L
Power Supply (PSU): EAX63729001 - LGP4247-11SPL
PWM Power: FAN7930B (PFC), 3BR4765JZ (Standby DIP-7), L6599AD (PWM Resonant)
MOSFET Power: K10A60D
MainBoard: EAX64290501 (0) EBR74015340
IC MainBoard: NTP-7100, NT5CB64M16DP-CF, H5TQ1G63DFR, F0514A, 25X20BVNIG, LVS244A
Tuner: TDTJ-S001D
Control: AKB72914277, IR: LW4500 LV2500 LK550_V1.7
Specifications 42LW4500
LG 42LW4500
General repair guidelines for TV LCD LED
The malfunction of the power supply is often manifested corny - the TV does not turn on, does not make any sounds, does not light and does not blink with any indicators. If there are no swollen filter capacitors in the secondary rectifiers, the power supply diagnostics 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 - K10A60D diodes and transistors for the possibility of an avalanche or thermal breakdown.
If the power keys of the pulse converter are not equal, you should pay attention to other elements in their bundling, which may be the result or cause of their breakdown.
If there is no image when you turn on the LG 42LW4500, or it appears and immediately disappears, but there is sound, most likely there is a malfunction in the backlight LED circuit of the LC420EUF (SD) panel (F2), or in the LED node of the driver-converter of their power supply.
A malfunction in the backlight circuits often occurs due to an open in the power circuit of the LED lines. It requires disassembling the panel and checking the LEDs themselves, the rations of their terminals, as well as the reliability of the connections in the connectors and rations of the terminals.
To check the health in the LED circuit, it is better to use a current source with a maximum voltage of 200V. We do not recommend using any voltage sources for this purpose. You can check each LED individually with a simple Chinese multimeter (powered by 9 volts) in the P-N-junction test mode. If you connect the red probe of the multimeter to the anode of the LED, and the black to its cathode, then the 3-volt LED will light up slightly, and in the opposite direction you can detect the transition of the emergency zener diode. A zener diode PN junction indirectly indicates a LED-a
In cases of attempts to repair the motherboard EAX64290501 (0) V3.01.4, it is necessary to check the operation of linear stabilizers and power converters of its microcircuits and, if possible, update the software (software). BGA chips can sometimes be diagnosed with local heating.
In some cases, it is necessary to check or replace (if necessary) the elements of the MB board (SSB) - NTP-7100, NT5CB64M16DP-CF, H5TQ1G63DFR, F0514A, 25X20BVNIG, LVS244A. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
Before replacing the TDTJ-S001D tuner, if there is no tuning for the channels, you must first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus
Owners and users of the LG 42LW4500 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 42LW4500, 42LW451C, 42LW450A, 42LW450N, 42LW450U Chassis LD01U.


 The appearance of the MainBoard EAX64290501 is shown in the figure below:
EAX64290501
EAX64290501 can be used in TVs:
LG 32LV2500-ZA (Panel T315XW06 V.3), LG 37LV3500-ZA (Panel T370HW05 V.1), LG 42LV3400-ZA (Panel T420HW08 V.1), LG 32LK530 (Panel LC320WUD (SC)(A3)), LG 37LK430 (Panel LC370WUE), LG 32LK451 ZA (Panel T315HW04 V.9), LG 42LV3551 (Panel LC420EUN (SD) (V3)), LG 47LW4500 (Panel LC470EUF (SD)(F2)), LG 32LK551 ZB (Panel LC320WUD (SC)(A2)), LG 42LV3500 (Panel LC420EUN (SD)(V3)), LG 42LK551 ZB (Panel V420H2-LH5), LG 42LK451 42LK451-ZG.BRUYLJU (Panel T420HW09 V0), LG 42LK530 (Panel LC420WUF (SC)(A2)), LG 47LK950 ZA (Panel LC470WUF (SD)(P1)), LG 32LW4500 ZB (Panel LC320EUD (SD)(P1)), LG 42LW4500 ZB (Panel LC420EUF (SD)(PX)), LG 42LV4500 DA (Panel LC420EUF (SD)(A1)), LG 32LV4500 (Panel LC320EUD (SD)(A4)), LG 42LV369C (Panel T420HW08 V.9).
PSU Advanced
The 42LW4500 model uses the EAX63729001 power supply unit using the PFC (Power Factor Correction) node - an active filter of the highest harmonics of the current consumption. In fact, this is a boost converter based on the FAN7930B 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 42LW4500:
Installed matrix (LED-panel) LC420EUF (SD) (PX) or LC420EUF (SD) (F2).
The matrix control uses the Timing Controller (T-CON) T-CON :.
The LED driver PPW-LE42GD-0 (A) is used to power the backlight LEDs, it is controlled by the PWM controller SW5508, SW5026. As the power elements of the LED driver, keys of the FDD850N10L type are used.
The necessary supply voltages for all nodes of the LG 42LW4500 TV are generated by the EAX63729001 power module or its analogs using FAN7930B (PFC), 3BR4765JZ (Standby DIP-7), L6599AD (PWM Resonant) microcircuits, and K10A60D type power switches.
MainBoard - the main board (motherboard) is an EAX64290501 module, using NTP-7100, NT5CB64M16DP-CF, H5TQ1G63DFR, F0514A, 25X20BVNIG, LVS244A, and others microcircuits.
The TDTJ-S001D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC420EUF-SDPX
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 (2H)
Brightness: 360 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 16.7M / 1.06B (8-bit / 8-bit + Dithering), CIE1931 68%
Response Time: 5 (G to G); 8 (MPRT)
Frequency: 120Hz + 120Hz
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (4 ch, 8/10-bit), 92 pins
Voltage: 12.0V