Monday, 2 March 2020

REPAIR / SERVICING TV LG 47LM580T

Technical description and composition of the LG 47LM580T TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 47LM580T
Chassis / Version: LD21B
Panel: LC470EUE (SE) (U1)
LED backlight: 6920L-0131D, 6920L-0131C
T-CON: 6870C-0418A
LED driver (backlight): integrated into PSU
PWM LED driver: GPCD2430A, 100BCA148AZOH, 3843CM
MOSFET LED driver: DB46BN
Power Supply (PSU): EAX64310401 (1.4) EAY62512701 LGP4247H-12LPB
PWM Power: L6599AD (PWM resonant), FAN7930 (PFC), STR-A6059H (Standby)
MOSFET Power: 18NM60N, 13NM60
MainBoard: EAX64317404 (1.0) EBR75084304, SAA35916762, SAA35948821
IC MainBoard: CPU: LGE2111A-T8, Nand: H27U1G8F2BTR, DDR: K4B1G1646G-BCK0, Spi: MX25L8006E
Tuner: TDSN-G301D
Control: AKB73615307; IR EBR74561004, LM35-55
Specifications 47LM580T
LG 47LM580T
General repair guidelines for TV LCD LED
In cases where the LG 47LM580T TV does not turn on, does not respond to the remote control and buttons, no indicators on the front panel light up or blink, and there are no sounds and no signs of operability when turning on, the EAX64310401 (1.4) EAY62512701 power module is most likely to be faulty or there is no standby power. When diagnosing and repairing the power supply, after replacing the swollen capacitors of the secondary rectifier filters (if any), you must first check the mains fuse. When it is broken, the power elements of transistors and rectifier bridge diodes should be checked for avalanche (thermal) 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. Possible defective PWM chip from the manufacturer.
If the LG 47LM580T does not have an image, but there is sound, a malfunction of the backlight LEDs of the LC470EUE (SE) (U1) panel or their power converter, the LED driver, may occur.
In case of breaks in the LED circuit, a complete disassembly of the panel is required, the LEDs are checked for an open circuit, as well as the reliability of the connections in the connectors and rations of the terminals.
It should be remembered that it is not possible to determine the open circuit in the LED lines without disassembling the panels with a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required. Then it is necessary to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow you to open the LED in the forward direction or dual LEd are used, then the PN junction of the emergency zener diode can indirectly serve as a health indicator. In case of LED-a failure, the zener diode PN junction will either be cut off or broken into short-circuit.
Diagnosis and repair of the EAX64317404 (1.0) EBR75084304, SAA35916762, SAA35948821 motherboard usually begins with a test of the performance of the stabilizers and power converters of the module chips. In some cases, a software update is required.
In cases of attempts to repair the MB (SSB) board, it is necessary to check the health of its elements - CPU: LGE2111A-T8, Nand: H27U1G8F2BTR, DDR: K4B1G1646G-BCK0, Spi: MX25L8006E which may require replacement with new ones. If a BGA processor is installed, there is a possibility of a violation of the soldering of the contacts of its conclusions with the board (it is diagnosed by heating).
The malfunction of the TDSN-G301D tuner is established after checking the software and all the supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be controlled by an oscilloscope.
Owners and users of the LG 47LM580T 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!



Service manual and schematic diagram ------------------------->   LG CHASSIS LD21B; MODEL 47LM580S, 47LM580T, 47LM585S, 47LM580S/580T-ZA 47LM585S-ZD

Panel backlight:
6922L-0018A LEFT 47 V12 Edge REV1.4 7 L-type 6920L-0131C
6922L-0017A RIGHT 47 V12 Edge REV1.4 7 R-type 6920L-0131D.

  schematic diagram ------------------------->   EAX64310401 Power supply


 The appearance of the MainBoard EAX64317404 is shown in the figure below:
EAX64317404
EAX64317404 can be used in TVs:
LG 32LS560T (Panel LC320EUN (SE)(M2)), LG 42LS5600 (Panel T420HVN01.1), LG 47LM580T (Panel LC470EUE (SE)(U1)), LG 42LM3400 (Panel LC420DUN (SE)(U2)), LG 37LS560T (Panel LC370EUN (SE)(M2)), LG 32LM340T (Panel LC320DXN (SE)(U3)), LG 47LM615S (Panel LC470EUE (SE)(U1)), LG 32LM3400 32LM3400-ZA (Panel LC320DXN (SE)(U2)).
PSU Advanced
The 47LM580T model uses the EAX64310401 power supply unit using the PFC (Power Factor Correction) node - an active filter of the highest harmonics of the current consumption. In fact, this is a boost converter based on the FAN7930 PWM controller, which eliminates the charge current of the electrolytic capacitor of the rectifier filter directly from the network through open diodes when its charging current is determined by its reactance.
As a result of the operation of the converter, the envelope of the high-frequency pulses of the input current of the converter will repeat the shape and phase of the input voltage. The health of the PFC node can be indirectly judged by the presence of an increased constant voltage (about + 380V) on the capacitor of the rectifier network in operating mode.
The appearance of the power supply
Main features of the device LG 47LM580T:
Installed matrix (LED panel) LC470EUE (SE) (U1).
The matrix control uses the Timing Controller (T-CON) 6870C-0418A.
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by a PWM controller GPCD2430A, 100BCA148AZOH, 3843CM. As power elements of the LED driver, keys of the DB46BN type are used.
The necessary supply voltages for all nodes of the LG 47LM580T TV are generated by the EAX64310401 power module or its analogs using L6599AD (PWM resonant), FAN7930 (PFC), STR-A6059H (Standby) microcircuits and power switches of the 18NM60N, 13NM60 type.
MainBoard - the main board (motherboard) is an EAX64317404 module using CPU chips: LGE2111A-T8, Nand: H27U1G8F2BTR, DDR: K4B1G1646G-BCK0, Spi: MX25L8006E and others.
The TDSN-G301D tuner provides television reception and channel tuning.
Information from an alternative source:
LG 47LM580T Chassis LD21B
Panel Type (Matrix): LC470EUE (SE) (U1)
Motherboard: EAX64317403 (1.0), Tuner: TDSN-G301D EBL610B0001
T-con: 32/37/42/47/55 FHD TM120 P / N: 6870-0418A
PSU: EAX64310401 (1.4) P / N: EAY62512701
Remote control: AKB73615307