Technical description and composition of the LG 49LF640V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 49LF640V ZD
Chassis / Version: LD51H
Panel: LC490DUE (MG) (P2)
LED backlight: LG Innotek DRT 3.0 49_A / B type Rev03.1_140218
T-CON: 6870C-0481A
LED driver (backlight): integrated into PSU
Power Supply (PSU): EAX66203101 (1.8) LGP4760RI-15CH2
MainBoard: EAX66207203 (1.0)
IC MainBoard: AT24C256, H26M31001HPR (e-NAND), K4B4G1646D-BCK0, K4B2G1646Q-BCK0, TPS65175B, NTP7515D
Tuner: TDJM-G301D
Control: IR: EBR78480602
Specifications 49LF640V
LG 49LF640V
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 49LF640V TV does not turn on, does not respond to the remote control and the control panel buttons, the indicators do not light or flash.
With such manifestations, in some cases, the EAX66203101 power module is faulty. Then it is necessary to measure its output voltages and, in case of their complete or partial absence, it is necessary to check the serviceability of power switches and rectifier diodes of the converters for a possible short circuit.
In case of any breakdown of semiconductors in the secondary circuits, the converter can usually work normally in emergency short circuit mode. There are no output voltages. And during short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and less often the current sensor at the source of the key.
Mos-Fet power switches, used in switching power supplies, sometimes fail due to a malfunction of any other elements that can put it out of operation in key mode or create an excess of the maximum permissible parameters of the switch. These can be elements supplying the PWM controller, frequency-setting or damping circuits, or negative feedback elements in the stabilization circuit. PWM controllers, in the absence of visible damage or explicit short-circuit between the terminals, 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.
A malfunction is usually most likely in these cases at the backlight nodes of the display matrix. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
To detect a break in the LED lines without disassembling the panel, a current source is required. It is impossible to open transitions connected in series with a simple multimeter; voltage of several tens of volts is necessary.
- The indicator blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the EAX66207203 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). If it is not possible to replace the MB (SSB) card, you need to check the health of its elements - AT24C256, H26M31001HPR (e-NAND), K4B4G1646D-BCK0, K4B2G1646Q-BCK0, TPS65175B, NTP7515D. Defective components should be replaced.
If there is no reception of television channels, but the TV is working properly from external devices, first of all it is necessary to check the power supply of the TDJM-G301D tuner and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Once again, remind users! Attempts to self-repair the TV LG 49LF640V without the appropriate qualifications and necessary experience can lead to its complete non-repairability!
Service manual / schematic diagram ----------------------> LG 49LF640V, 55LF640V Chassis LD51H
The appearance of the MainBoard EAX66207203 is shown in the figure below:EAX66207203
EAX66207203 can be used in TVs:
LG 50LF653V (Panel LC500DUH (MG)(P1)), LG 40LF630V 40LF630V-ZA.BRUJLDU (Panel V400HJ6-PE2 HC400DUN-VCKN1-214X), LG 40LF634V (Panel V400HJ6-PE2 Rev.C1 HC400DUN-VCKN1-214X).
The appearance of the power supply
Main features of the device LG 49LF640V:
Installed matrix (LED panel) LC490DUE (MG) (P2).
The matrix control uses the Timing Controller (T-CON) 6870C-0481A.
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 49LF640V TV is carried out by the EAX66203101 power module, or its analogues.
MainBoard - the main board (motherboard) is an EAX66207203 module, using chips AT24C256, H26M31001HPR (e-NAND), K4B4G1646D-BCK0, K4B2G1646Q-BCK0, TPS65175B, NTP7515D and others.
The TDJM-G301D tuner provides TV reception and channel tuning.
