Technical description and composition of the LG 49UF8507 TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 49UF8507 49UF8507V
Chassis / Version: LD53H / LD53J
Panel: LC490EQE (XH) (F1)
T-CON: 6870C-0553A V15 UHD TM120 LGE VER1.0
LED driver (backlight): integrated into PSU; 60V 0.96A
Power Supply (PSU): EAX66306501 (2.0)
MainBoard: EAX66466803 (1.0) EBT64141801
IC MainBoard: CPU: LGE5352-A1
Tuner: TDJM-G301D
Specifications 49UF8507
LG 49UF8507
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The LG 49UF8507 TV does not turn on at all. There is no reaction to the remote control and control buttons from the front panel. Indicator lights do not light or flash.
Most likely in this case, the main switching power supply (IIPS) EAX66306501 is faulty. It is necessary to measure its secondary output voltages, and if they are absent, check the power switches and rectifier diodes in the converters for a short circuit.
In case of breakdowns of diodes in the secondary circuits, the converter can operate in emergency short circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor at the source of the key usually breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM), in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it on and immediately disappears
In such cases, the most likely malfunction of the LED backlight elements. 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.
It is impossible to detect a break in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect the probes in the forward direction to it (red probe to the anode, black to the cathode). In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as a health indicator. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- The indicator blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the EAX66466803 motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software).
Before replacing the TDJM-G301D 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
Once again, remind users! Attempts to self-repair the TV LG 49UF8507 without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
Service manual / schematic diagram --------------> LG 49UF8507 Chassis L#5XJ.
CHASSIS : LD53H / LD53J; MODEL : 49UF85**, 49UF85**-Z*
The appearance of the MainBoard EAX66466803 is shown in the figure below:EAX66466803
The appearance of the power supply
Main features of the device LG 49UF8507:
Installed matrix (LED-panel) LC490EQE (XH) (F1).
The matrix control uses the Timing Controller (T-CON) 6870C-0553A.
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 49UF8507 TV is carried out by the EAX66306501 power module, or its analogues.
MainBoard - the main board (motherboard) is an EAX66466803 module using CPU chips: LGE5352-A1 and others.
The TDJM-G301D tuner provides TV reception and channel tuning.
