Tuesday, 3 March 2020

REPAIR / SERVICING TV LG 47LM615S

Technical description and composition of the LG 47LM615S TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 47LM615S
Chassis / Version: LD21B
Panel: LC470EUE (SE) (U1)
T-CON: 32/37/42/47/55 FHD TM120 Ver 1.0 VFNHBWF
LED driver (backlight): integrated into PSU; 58.5V 1.26A
PWM LED driver: 2843B, GPCD2430A, 100BCA148AZOH
MOSFET LED driver: 86106LZ
Power Supply (PSU): EAX64310401 (1.4) LGP4247H-12LPB EAY62512701
PWM Power: L6599AD (PWM resonant), FAN7930 (PFC), STR-A6059H (Standby)
MOSFET Power: 18NM60N, 13NM60N
MainBoard: EAX64317404 (1.0) EBT62225731
IC MainBoard: CPU: LGE2111A-T8, Nand: H27U1G8F2BTR, DDR: K4B1G1646G-BCK0, Spi: MX25L8006E
Tuner: TDSN-G301D
Specifications 47LM615S
LG 47LM615S
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The LG 47LM615S TV does not turn on, does not respond to the remote control and the control panel buttons, the indicators do not light or flash.
Typically, with such manifestations, the defect is caused by faulty elements in the EAX64310401 main power module. It is necessary to measure its secondary output voltages, and in case of their absence, check the serviceability of the power switches (18NM60N, 13NM60N) of the converters and rectifier diodes for a possible short circuit.
In case of breakdowns in the secondary circuits, the converter can emergencyly operate in the short circuit mode, and during short circuit in the power elements of the primary circuit, the main fuse usually 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. It can be supply, damper circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power switch may be PWM (PWM) L6599AD (PWM resonant), FAN7930 (PFC), STR-A6059H (Standby). It is checked only by replacement with a known good one.
- There is no image, there is sound, it responds to the remote control, the channels are switched. In some cases, the image appears when you turn on and immediately disappears.
In most cases, the malfunction is caused by the lack of a backlight display. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
To check the LED strips, to open all the transitions of the LEDs, several tens of volts or more are needed, it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED transitions in forward bias, sometimes you can detect the presence of a PN junction of the protective zener diode by connecting the probes in the opposite direction. If the zener diode is broken or broken in short-circuit, then the LED is faulty and needs to be replaced.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the EAX64317404 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). In some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - CPU: LGE2111A-T8, Nand: H27U1G8F2BTR, DDR: K4B1G1646G-BCK0, Spi: MX25L8006E with new or obviously working ones. In cases where BGA technologies are used, defects are usually localized by the heating method.
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.
Attention! For users and owners of 47LM615S TVs who do not have the appropriate qualifications, knowledge and experience, we categorically do not recommend attempting self-repair in order to avoid negative consequences that could lead to complete non-repairability of the device.


Service manual / schematic diagram ---------------->  LG 47LM615S, 47LM615S-ZE, 47LM615T, 47LM615T-ZE Chassis LD21B.

  schematic diagram ---------------->   EAX64310401 LGP4247H-12LPB EAY62512701 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)).
The appearance of the power supply
Main features of the device LG 47LM615S:
Installed matrix (LED panel) LC470EUE (SE) (U1).
The matrix control uses the Timing Controller (T-CON) 32.
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by a PWM controller 2843B, GPCD2430A, 100BCA148AZOH. As power elements of the LED driver, keys of type 86106LZ are used.
The necessary supply voltages for all nodes of the LG 47LM615S 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, 13NM60N 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.