Technical description and composition of the LG 42LM585T TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 42LM585T ZD
Chassis / Version: LD21B / LC21B
Panel: LC420EUE (SE) (F1)
LED backlight: 6922L-0016A (Cool); 6920L-0001C (LED)
T-CON: 6870C-0401B
LED driver (backlight): integrated into PSU; 67V 0.78A
PWM LED driver: R5F100BCAFP, AAT2430AISX
MOSFET LED driver: PHT4NQ10LT * 4
Power Supply (PSU): EAX64427101 (1.6) LGP4247L-12LPB
PWM Power: FAN7930BG (PFC), L6599AD (PWM Resonant), STR-A6059
MOSFET Power: STF13NM60N, STF10NM60N, FDT86106LZ
MainBoard: EAX64909901 EBR75084305
IC MainBoard: LGE2111A-T8, NAND FLASH: H27U1G8F2BTR / BC - 1 Gbit (128M x 8 bit), SPI: W25Q80, EEPROM: 24C256, AUDIO: STA380BWE
Tuner: TDSN-G301D EBL61080001
Control: AKB73615303; IR: EBR74986703, LM35-55, MB32B00, 1BF-3010B
Specifications 42LM585T
LG 42LM585T
General repair guidelines for TV LCD LED
In the absence of any signs of operability, when the LG 42LM585T 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 EAX64427101 (1.6) LGP4247L-12LPB TV power module. It is advisable to start the troubleshooting of the power supply module by checking the state of the electrolytic capacitors of the rectifier filters and the mains fuse. Defective capacitors should be replaced. If the mains fuse is broken, it is necessary to check first of all the power semiconductor elements - rectifier diodes and transistors, which are often found in such a state of breakdown.
In most cases, key breakdowns in switching power supplies (SMPS) do not occur for no reason and you should look for other faulty circuit elements that could provoke a defect. This can be dried electrolytic capacitors in the primary circuit, and faulty damper elements, as well as dangling resistors or punched semiconductor elements in the stabilization circuits. PWM chip FAN7930BG, L6599AD, STR-A6059, FDT86106LZ, D10100CT from the manufacturer is possible.
In cases where the LG 42LM585T TV has lost its image, and the sound is there and all other functions are operational, there is a possibility of a malfunction of the LED driver (converter for powering the backlight LEDs of the LC420EUE (SE) panel (F1)). When you turn on the TV, the image may appear briefly and disappear. It must be borne in mind that with such manifestations the LEDs themselves also fail.
Often in the absence of backlighting, disassembling the panel is required. It is necessary to check the serviceability of the transitions of the LEDs, as well as the reliability of the contact connections in the rulers and connectors.
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.
On the EAX64909901 EBR75084305 motherboard, in case of a malfunction, you should first check the operation of all the stabilizers and power converters of the microcircuits, and also, if necessary, update the software (software).
Often, the MB (SSB) card needs to be replaced in case of complex faults that are difficult to detect. When trying to repair, you should check its elements - LGE2111A-T8, NAND FLASH: H27U1G8F2BTR / BC - 1 Gbit (128M x 8 bits), SPI: W25Q80, EEPROM: 24C256, AUDIO: STA380BWE and replace failed chips with new ones. Some malfunctions may be due to the use of BGA soldering technologies in modern Main Board technologies. Typically, such defects are detected by local heating of the chip.
In the absence of tuning to the channels of on-air or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltage at the terminals of the TDSN-G301D EBL61080001 tuner. It is also necessary to check the presence of pulses of data exchange between the tuner and the processor via the I2C bus using an oscilloscope.
Attention to users! Self-repair of the LG 42LM585T TV without the appropriate qualifications and experience can lead to its complete non-repairability!
SCHEMATIC DIAGRAM ---------> LG 42LM580S, 42LM580T, 42LM585S, 42LM580S, 42LM580T-ZA, 42LM585S-ZD Chassis LD21B.
PSU SCHEMATIC DIAGRAM ---------> LG EAX64427101 EAY62608901 LGP4247L-12LPB PLDF-L103A
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.
The appearance of the MainBoard EAX64909901 is shown in the figure below:EAX64909901
EAX64909901 can be used on TVs:
LG 42LM580T-ZA (Panel LC420EUE (SE)(F1)), LG 42LM340T (Panel LC420DUN (SE)(U3)), LG 32LM580T (Panel LC320EUN (SE)(F3)), LG 42LM585T ZD (Panel LC420EUE (SE)(F1)), LG 42LM615T (Panel LC420EUE (SE)(F1)), LG 42LS560T 42LS560T-ZC (Panel T420HVN01.1).
PSU Advanced
The EAX64427101 power supply module is made using a Power Factor Correction (PFC) scheme to eliminate multiple AC harmonics introduced into the power supply by the device. The PFC is a Step-Up Converter based on the FAN7930BG PWM controller, which evenly distributes high-frequency pulses of the charging current of the electrolytic capacitor of the mains rectifier filter across a 50 Hz period. The current of its charge in this case will already be determined not by its reactance (usually 10-30 ohms for the network frequency), but by the elements of the converter. As a result, a change in the amplitude of the pulses (envelope) of the consumed current of the converter will repeat the shape and phase of the input sinusoidal voltage. The availability of an increased voltage (about + 380V) in the operating mode on the capacitor of the line filter indicates the serviceability of the PFC node.
The appearance of the power supply
Main features of the device LG 42LM585T:
Installed matrix (LED-panel) LC420EUE (SE) (F1).
The matrix control uses the Timing Controller (T-CON) 6870C-0401B.
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by a PWM controller R5F100BCAFP, AAT2430AISX. As power elements of the LED driver, keys of the type PHT4NQ10LT * 4 are used.
The necessary supply voltages for all nodes of the LG 42LM585T TV are generated by the EAX64427101 power module or its analogs using FAN7930BG (PFC), L6599AD (PWM Resonant), STR-A6059 microcircuits and power switches of the STF13NM60N, STF10NM60N, FDT86106LZ type.
MainBoard - the main board (motherboard) is an EAX64909901 module using LGE2111A-T8 chips, NAND FLASH: H27U1G8F2BTR / BC - 1 Gbit (128M x 8 bits), SPI: W25Q80, EEPROM: 24C256, AUDIO: STA380BWE and others.
The TDSN-G301D EBL61080001 tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC420EUE-SEF1
Type: a-Si TFT-LCD, Panel
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 930.24x523.26 mm
Surface: Antiglare (Haze 1%), Hard coating (3H)
Brightness: 360 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 16.7M (8-bit), CIE1931 68%
Response Time: 6 (G to G)
Frequency: 60Hz
Lamp Type: 6 strings WLED Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V