Technical description and composition of the LG 50LF650V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 50LF650V LG 50LF650V-ZA
Chassis / Version: LD51H
Panel: LC500DUH (MG) (P1)
LED backlight: DRT 3.0 50_A / B type Rev02 # 1_140218
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: WIFI: LGSBW41
Specifications 52LG5030
LG 50LF650V
General repair guidelines for TV LCD LED
Possible malfunctions
- LG 50LF650V TV does not turn on. There are no signs of operability. The indicators on the front panel do not light or flash, the TV does not respond to the remote control and control buttons.
With such manifestations, a malfunction is most likely to be detected in the EAX66203101 power module. It is then necessary to measure its output voltages and, if they are absent, you should check the power switches and rectifier diodes of the converters for the probability of a short circuit.
In case of any breakdowns in the secondary circuits, the converter can operate in emergency short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key more often 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
Often in such cases, there is no LED backlight. 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 an indicator of health. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- The TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly or blinks.
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.
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
We recommend the owners of the 50LF650V 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!
Service manual / schematic diagram ------------> LG 50LF650V Chassis LD51H
50LF65** 50LF65*-Z*
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 50LF650V:
Installed matrix (LED-panel) LC500DUH (MG) (P1).
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 50LF650V 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.
