Technical description and composition of the LG 49UJ655V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 49UJ655V
Chassis / Version: LJ7 Chassis
Panel: LC490DGG (FK) (M4)
LED driver (backlight): integrated into PSU
Power Supply (PSU): EAX67128101 (2.1) LGP49D-17V2
MainBoard: EAX67133404 (1.0)
IC MainBoard: Realtek K3Lp, FT24C256A, DTA2010M
Tuner: TDJA-G501D
Control: Wi-Fi: EAT63377302
Specifications 49UJ655V
LG 49UJ655V
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 49UJ655V TV does not turn on and does not show any signs of being turned on, does not respond to the control buttons or to the remote control.
Most often, with such manifestations, the main power supply module EAX67128101 is found to be faulty. It is necessary to measure its output voltages and, if they are absent, to check the short circuit probability in the converters power switches and rectifier diodes.
In case of breakdowns in the secondary circuits, the converter, as a rule, can emergency work in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse usually breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM microcircuits are usually checked by replacement with new ones, or obviously working.
- 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
A malfunction is usually most likely in these cases at the backlight nodes of the display matrix. 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 TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the EAX67133404 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). In cases of complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its chips Realtek K3Lp, FT24C256A, DTA2010M and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
Before changing the tuner TDJA-G501D, if there is no possibility of tuning to television channels, you should make sure that there are supply voltages that must be measured at the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Attention to users! Independent repair of the TV LG 49UJ655V without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
EAX67133404
Main features of the device LG 49UJ655V:
Installed matrix (LED-panel) LC490DGG (FK) (M4).
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 49UJ655V TV is carried out by the EAX67128101 power module, or its analogues.
MainBoard - the main board (motherboard) is an EAX67133404 module, using Realtek K3Lp, FT24C256A, DTA2010M chips, and others.
The TDJA-G501D tuner provides television reception and channel tuning.
