Technical description and composition of the LG 50LA644V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 50LA644V
Chassis / Version: LD33B / LC33B / LE33B
Panel: LC500EUN (SF) (F1)
LED backlight: 6920L-0001C & 6916L-1173A (cool)
T-CON: LC500DUE SFR1 Control Merge
LED driver (backlight): KLS-E500SNAHF06 A REV: 0.71 6917L-0123A
PWM LED driver: BD9470EFV
MOSFET LED driver: SF10A400HD, D482
Power Supply (PSU): EAX64908101 (2.2) LGP4755-13P EAY62851201
PWM Power: L6599AD (PWM Resonant), R2A20133DSP (PFC), FSD106LG (Standby)
MOSFET Power: STD13NM60N
MainBoard: EAX64797003 (1.2)
IC MainBoard: CPU: LGE2122, NAND: SAA36403538 VER. 3.20.33, H5TQ4G63AFR, SOUND: NTP7513
Tuner: EBL61240503 TDSQ-G601D (B)
Specifications 50LA644V
LG 50LA644V
General repair guidelines for TV LCD LED
In the absence of any signs of operability, when the LG 50LA644V does not turn on and does not signal anything with the control lights on the panel, there is a possibility of a malfunction of the EAX64908101 (2.2) LGP4755-13P TV power module. First of all, it is necessary to replace the swollen capacitors of the rectifier filters, if any. If the mains fuse is broken in the power supply, in most cases a breakdown of the power key (s) STD13NM60N is detected, which can be integrated with a PWM controller, or a separate field-effect transistor can be used. The rectifier bridge diodes and the electrolytic capacitor of the mains rectifier filter should also be checked.
If a breakdown of the power switch is detected, it should be remembered that in a switching power supply (IIP) it does not fail by itself without any reasons that should be sought by checking other elements of the primary circuit - electrolytic capacitors, resistors and semiconductor elements (diodes, transistors , zener diodes), as well as PWM controllers L6599AD, R2A20133DSP (PFC), FSD106LG (Standby), which can only be checked by replacement.
If the LG 50LA644V TV does not have an image, but there is sound, a malfunction in the backlight circuits of the LC500EUN SF F1 LED panel is likely.
The lack of backlight often occurs due to an open circuit in the LED circuit. There is a need for disassembling the panel and checking the LEDs themselves, as well as the same contact connections in the connectors and rations of the terminals.
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.
When trying to repair the motherboard, you should first check the serviceability of linear stabilizers or power converters of microcircuits and, if necessary, update the software (software).
Complex repair of MB (SSB) is possible only in the conditions of a service center with the necessary equipment. Checking or replacing CPU elements: LGE2122, NAND: SAA36403538 VER. 3.20.33, H5TQ4G63AFR, SOUND: NTP7513 requires the necessary training and professional skills to repair modules at the component level. Problems associated with the use of BGA soldering technologies can be diagnosed by warming up.
If there is no reception of television channels, but the TV is working properly from external devices, first of all you need to check the voltage of the tuner EBL61240503 TDSQ-G601D (B) and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Owners and users of the LG 50LA644V TV must remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!
To reduce the backlight current in LED drivers with a BD9470EFV controller (TSSOP-B28), it is necessary to proportionally increase the total resistance of the resistors from pin 8 (ISET) to the chassis. The resistance Rset (in kilo-ohms) is selected from the ratio 3000 / Iled, where Iled is the maximum current in each of the six channels in milliamps
SCHEMATIC manual -------------------> LG CHASSIS LD33B MODEL 50LA64** 50LA64**-Z*.
SCHEMATIC manual -------------------> LGP4755-13P EAX64908101 Power Supply schematic diagram.
The appearance of the MainBoard EAX64797003 is shown in the figure below:
EAX64797003
EAX64797003 can be used in TVs:
LG 42LA620V (Panel LC420DUE (SF)(U1)), LG 32LN570V (Panel LC320DUE (SF)(R1)), LG 50LA644V (Panel LC500EUN (SF)(F1)), LG 47LA660V (Panel LC470EUG (PF)(F1)), LG 47LA621V (Panel LC470DUE (SF)(U1)), LG 42LA644V (Panel LC420EUN (SF)(F2)), LG 39LA620V ZA (Panel T390HVJ01.0), LG 42LA621V ZD (Panel LC420DUE (SF)(U1)), LG 32LA621V ZD (Panel LC320DUE (SF)(U1)), LG 32LN655V (Panel LC320EUB (PF)(M1)), LG 42LA667V (Panel LC420EUH (PF)(P1) ), LG 47LN613V (Panel LC470DUE (SF)(R4)), LG 32LA667V ZB (Panel LC320EUB (PF)(P1)), LG 55LA660V ZA (Panel LC550EUH (PF)(P1)), LG 47LA620V ZA (Panel LC470DUE (SF)(U1)), LG 32LN613V ZB (Panel LC320DUE (SF)(R4)), LG 42LN655V ZB.BRUZLJU (Panel LC420EUH (PF)(M1)), LG 32LA644V ZA (Panel LC320EUN (SF)(F1)), LG 42LN613V (Panel LC420DUE (SF)(R4)), LG 47LA690V ZB (Panel LC47EUH (PF)(P1)), LG 47LA662V (Panel LC470EUG (PF)(F1)), LG 42LA645V 42LA645V-ZC.BRUYLJU (Panel LC420EUN (SF)(F3)), LG 32LA660V (Panel LC320EUB (PF)(P1)), LG 47LA644V 47LA644V-ZA (Panel LC470EUN (SF)(F2)), LG 50LA667S (Panel T500HVD02.1), LG 47LA691V (Panel LC470EUH (PF)(P1)), LG 32LA662V (Panel LC320EUB (PF)(P1)).
PSU Advanced
According to the conditions of compliance with modern world standards for household switching power supplies, the EAX64908101 module provides for the use of a Power Factor Correction unit. The PFC circuit is a flyback converter based on the R2A20133DSP PWM controller. The reactance of an electrolytic capacitor of a line filter at a frequency of 50-60 Hz is usually not more than 20-30 ohms and its charge directly from the network through open diodes could reach tens of amperes per pulse if no filtering were applied.
As a result of the PFC conversion, an increased voltage on the capacitor (about 380V) cannot directly open the rectifier diodes, on the anode of which the voltage will always be slightly less (about 300V) and then its charging current will always be limited by the elements of the PWM controller. As a result, the envelope of the high-frequency pulses of the consumed current will repeat the shape and phase of the input sinusoidal voltage. The presence of an increased voltage (+ 380V) on the network capacitor indicates the serviceability of the PFC node.
The appearance of the power supply
Main features of the device LG 50LA644V:
Installed matrix (LED-panel) LC500EUN (SF) (F1).
The matrix control uses the Timing Controller (T-CON) LC500DUE.
To power the backlight LEDs, the KLS-E500SNAHF06 LED driver is used, controlled by the BD9470EFV PWM controller. As power elements of the LED driver, keys of the type SF10A400HD, D482 are used.
The necessary supply voltages for all nodes of the LG 50LA644V TV are generated by the EAX64908101 power supply module or its analogs using L6599AD (PWM Resonant), R2A20133DSP (PFC), FSD106LG (Standby) microcircuits and power switches of the STD13NM60N type.
MainBoard - the main board (motherboard) is an EAX64797003 module using CPU chips: LGE2122, NAND: SAA36403538 VER. 3.20.33, H5TQ4G63AFR, SOUND: NTP7513 and others.
The tuner EBL61240503 TDSQ-G601D (B) provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: LG Display
Model: LC500EUN-SFF1
Type: a-Si TFT-LCD, Panel
Diagonal size: 50 inch
Resolution: 1920x1080, FHD
Display Mode: IPS, Normally Black, Transmissive
Active Area: 1095.84x616.41 mm
Surface: Antiglare (Haze 1%), Hard coating (2H)
Brightness: 350 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 16.7M (8-bit), CIE1931 68%
Response Time: 6 (G to G)
Frequency: 60Hz
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V
