Technical description and composition of the LG 40UB800V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 40UB800V 40UB800V-ZA
Chassis / Version: LD48V
Panel: V400DK1-KE1
LED backlight: V400D1-KS1-TLEM2
T-CON: V500DK2-CKS2
LED driver (backlight): integrated into PSU
Power Supply (PSU): EAX65942801 LGP40-14UL18
MainBoard: EAX66085703 EBT63174503
IC MainBoard: LGE7411 / LGE4331B4, 25L320BE, AT24C256C, H5TQ4G63AFR, THGBMAG5A1JBAIR, NTP7514
Tuner: TDJM-G251D
Specifications 40UB800V
LG 40UB800V
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The LG 40UB800V TV does not turn on, does not show any signs of turning on, does not respond to the control buttons or to the remote control.
With such manifestations, the EAX65942801 main power module may fail. In order to diagnose a malfunction, it is necessary to measure its output voltages and, if they are absent, check the serviceability of the power switches of the converters and rectifier diodes for a possible short circuit.
In case of breakdowns of semiconductor elements in the secondary circuits, the converter can emergency operate in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse often breaks.
The breakdown of Mos-Fet keys used in switching power supplies is often triggered by malfunctions of other elements, for example, in the PWM controller power circuit, in frequency-setting or damping circuits, as well as in elements of the Negative Stabilization Feedback. PWM microcircuits, in the absence of a short circuit between the terminals and external damage, are checked by replacing with new ones, or obviously working.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
Often in such cases, the malfunction is caused by the lack of a backlight display. The reason can be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
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. In the absence of a current source, each LED individually can be checked 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. The serviceability of the PN transition of the zener diode indirectly indicates the serviceability of LED-a.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
In such cases, you should diagnose the EAX66085703 motherboard, and start by checking the health of the stabilizers and power converters of the microcircuit and matrix. If necessary, update or replace the software (software).
If the TV works normally from external devices, but does not tune into television channels, the TDJM-G251D may be malfunctioning. In such cases, first of all, you need to make sure that there are supply voltages at its corresponding terminals and make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Attention TV owners! Self-repair attempts by LG 40UB800V are not recommended by the manufacturer and can lead to serious negative consequences!
Schematic diagram ------------> LG 40UB800V Chassis LD48V
The appearance of the MainBoard EAX66085703 is shown in the figure below:EAX66085703
EAX66085703 can be used in TVs:
LG 42UB820V 42UB820V-ZH.ARUWLJU (Panel LC420EQE (PG)(M1)), LG 49UB830V (Panel LC490EQE (XG)(F2)), LG 49UB820V 49UB820V-ZH (Panel LC490EQE (XG)(F2) ), LG 40UB800V 40UB800V-ZA (Panel V400DK1-KE1).
The appearance of the power supply
Main features of the device LG 40UB800V:
Installed matrix (LED-panel) V400DK1-KE1.
The matrix control uses the Timing Controller (T-CON) V500DK2-CKS2.
To power the backlight LEDs, a converter is used, combined with a power supply.
The formation of the necessary supply voltages for all nodes of the LG 40UB800V TV is carried out by the EAX65942801 power module, or its analogues.
MainBoard - the main board (motherboard) is an EAX66085703 module using LGE7411 / LGE4331B4, 25L320BE, AT24C256C, H5TQ4G63AFR, THGBMAG5A1JBAIR, NTP7514 and others microcircuits.
The TDJM-G251D tuner provides TV reception and channel tuning.