Technical description and composition of the LG 49LJ622V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 49LJ622V
Chassis / Version: LJ7 LD75M / LD75H
Panel: LC490DUE (FK) (M3)
LED backlight: 6870C-1935A, 6870C-1936A
T-CON: 6870C-0532C; SW0871, SW5084B
LED driver (backlight): integrated into PSU
PWM LED driver: LC5910
MOSFET LED driver: KF9N25
Power Supply (PSU): EAX67108001 (1.5) - LGP49D-17F1 P / N: EAY64529701
PWM Power: SSC3S927
MOSFET Power: 60S650CE, 60R580Q
MainBoard: EAX67129603 (1.0)
IC MainBoard: SEC 725 8031 KLW4G1FEPD, FT24C256A, K4B4G164GE x2, R5F100GEAFB, DTA2010M
Tuner: EBL61840901 TDJA-G501D
Specifications 49LJ622V
LG 49LJ622V
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 49LJ622V TV does not turn on at all. The control lights do not light or flash. The TV on the remote control and the control panel buttons do not respond.
Most often, with such manifestations, the main power module EAX67108001 is found to be faulty. It is then necessary to measure its output voltages and, if they are absent, you should check the power switches (60S650CE, 60R580Q) and rectifier diodes of the converters for a short circuit probability.
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.
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) SSC3S927, 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 and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
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 TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the EAX67129603 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 attempts to repair the MB (SSB) board, it is necessary to check the health of its elements - SEC 725 8031 KLW4G1FEPD, FT24C256A, K4B4G164GE x2, R5F100GEAFB, DTA2010M which may require replacement with new ones. If a BGA processor is installed, there is a possibility of a violation of the soldering of the contacts of its conclusions with the board (it is diagnosed by heating).
Before changing the tuner EBL61840901 TDJA-G501D, if it is not possible to tune to television channels, make sure that there are supply voltages that need to 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
We recommend owners of the 49LJ622V TV for repair only to qualified specialists with the necessary work experience! Self-repair attempts without the appropriate knowledge and skills can lead to irreversible negative consequences!
FIRMWARE SPI FLASH -----------------> LG 49LJ622V LJ7 LD75M/LD75H, Main: EAX67129603 (1.0), Panel: LC490DUE (FK)(M3).
The panel has 24 LED 3 volts. current = 660 mA.
You can reduce the current by increasing the value of the resistor R801 to 2.5 Ohm.
The appearance of the MainBoard EAX67129603 is shown in the figure below:EAX67129603
The appearance of the power supply
Main features of the device LG 49LJ622V:
Installed matrix (LED-panel) LC490DUE (FK) (M3).
The matrix control uses the Timing Controller (T-CON) 6870C-0532C ;.
To power the backlight LEDs, a converter is used, combined with the power supply, controlled by the LC5910 PWM controller. As the power elements of the LED driver, keys of the KF9N25 type are used.
The necessary supply voltages for all nodes of the LG 49LJ622V TV are generated by the EAX67108001 power module or its analogs using SSC3S927 microcircuits and power switches of the 60S650CE, 60R580Q type.
MainBoard - the main board (motherboard) is an EAX67129603 module, using SEC 725 8031 KLW4G1FEPD, FT24C256A, K4B4G164GE x2, R5F100GEAFB, DTA2010M and others.
The tuner EBL61840901 TDJA-G501D provides the reception of television programs and tuning to channels.
