Technical description and composition of the LG 55LM860V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 55LM860V
Chassis / Version: LD23E
Panel: LC550EUH (PE) (F1)
LED backlight: 6920L-0001C (6916L0832A), (6916L0833A)
T-CON: EAX64583702-1.0
LED driver (backlight): integrated into PSU; 78V 1.25A
PWM LED driver: UC2843BD1 (Step-Up LED), AAT2430AISX, R5F100BCAFP
MOSFET LED driver: STF19NF20, PHT4NQ10LT * 12
Power Supply (PSU): EAX64744301 EAY62512802, LGP55H-12LPB-3P
PWM Power: HS01G (PFC), A6059H (STB), L6599AD (PWM resonant)
MOSFET Power: STF18NM60N * 2 (PFC), STF13NM60N * 2
MainBoard: EAX64503907 (1.0) EBR75392202, SAA35968926, SAA36001709, SAA36039507
IC MainBoard: CPU: LG1152D-B1; Scaler: SII9587CNUC; SOUND: NTP-7500L
Tuner: TDSQ-G351D
Control: AKB73615303
Technical Specifications 55LM860V
LG 55LM860V
General repair guidelines for TV LCD LED
Sometimes the LG 55LM860V TV just does not turn on. No control lights on the front panel are lit or blinking, the TV does not respond to the remote control and does not make any sounds or any signs of life when turned on. The most likely cause of the malfunction is the failure of the EAX64744301 EAY62512802, LGP55H-12LPB-3P common power module. If it is working properly, you must check the standby batteries on the Main Board. In the general case, first of all, it is necessary to check the electrolytic capacitors of the secondary rectifier filters and the fuse at the input of the network. If it is broken, then you should check for breakdown of the PN junctions of the rectifier bridge diodes and the key transistor of the converter, which can either be on a separate radiator or integrated with a PWM controller in a common chip. Possible options.
Power switches in switching power supplies (SMPS) fail extremely rarely for no reason and, if they are broken, it is necessary to look for a malfunction in the stabilization circuits by checking electrolytic capacitors, semiconductor devices, and resistors in the primary circuit. The cause may be a malfunction of the PWM controller chip, which can only be checked by replacing it with a new or obviously working one.
If the LG 55LM860V does not have an image, but there is sound and the TV is controlled by the remote control, a malfunction in the backlight circuits of the LC550EUH (PE) (F1) panel is likely. LEDs or their power converter - LED driver may be faulty. Often in such cases, when you turn on the TV, an image appears and immediately disappears. First of all, it is necessary to verify the operability of the electrolytic capacitors of the rectifier filter supplying the backlight assembly.
To check the health of the LEDs, as well as contact connections in the ruler circuit, it is necessary to disassemble the panel.
It is impossible to check the LED line for breaks without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts will be required, and ideally, a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters, as a rule, light up a single 3-volt LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as a health indicator. In faulty LEDs, the 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).
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 TDSQ-G351D tuner and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Attention! For users and owners of 55LM860V TVs who do not have the appropriate qualifications, knowledge and experience, we strongly recommend against self-repair attempts in order to avoid negative consequences that could lead to complete non-repairability of the device.
Service manual / schematic diagram ------------> LG CHASSIS LD23E; MODEL 55LM860V/W, 55LM860V/W-ZB.
PSU / schematic diagram ------------> LGP55H-12LPB-3P EAX64744301 EAY62512802 Power Supply schematic diagram
To reduce the backlight current in LED drivers with the AAT2430AISX controller, increase the resistance of the resistor from terminal 50 (ISET) to the housing, for example, from 3 KOhm to 4.7 KOhm. Currents will proportionally decrease in each of the 16 channels. With a parallel connection of channels, currents are summed.
PSU Advanced
On the 55LM860V TV, the EAX64744301 power module is installed using the PFC (Power Factor Correction) scheme acting as an active filter to eliminate the higher harmonic components of the current consumption. The step-up converter based on the HS01G PWM controller does not allow the input rectifier filter's electrolytic capacitor to be connected to the network directly through open diodes when the charge current is determined by its reactance (of the order of 15-30 ohms at a frequency of 50 Hz). As a result of the conversion, the charging current of the capacitor will be determined in such a way that the envelope of the high-frequency pulses of the input current will repeat the phase and shape of the sine wave of the input voltage. The health check of the PFC unit is carried out by measuring the DC voltage on the capacitor of the rectifier network. In operating mode, it should be around 380V, in standby approximately 300V.
The appearance of the power supply
Main features of the device LG 55LM860V:
Installed matrix (LED-panel) LC550EUH (PE) (F1).
The matrix control uses the Timing Controller (T-CON) EAX64583702-1.0.
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by a PWM controller UC2843BD1 (Step-Up LED), AAT2430AISX, R5F100BCAFP. As the power elements of the LED driver, keys of the type STF19NF20, PHT4NQ10LT * 12 are used.
The necessary supply voltages for all nodes of the LG 55LM860V TV are generated by the EAX64744301 power module or its analogs using HS01G (PFC), A6059H (STB), L6599AD (PWM resonant) microcircuits and power switches of the STF18NM60N * 2 (PFC), STF13NM60N * 2 type .
MainBoard - the main board (motherboard) is an EAX64503907 module, using CPU chips: LG1152D-B1; Scaler: SII9587CNUC; SOUND: NTP-7500L and others.
The TDSQ-G351D tuner provides TV reception and channel tuning.
