Monday, 2 March 2020

REPAIR / SERVICING TV LG 47LE5500

Technical description and composition of the LG 47LE5500 TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 47LE5500 ZA
Chassis / Version: LD03E
Panel: LC470EUH (SC) (A1)
LED driver (backlight): integrated into PSU
Power Supply (PSU): PLDH-L904A EAY60803501 3PCGC10008A-R
PWM Power: VIPER27H (Standby), ICE2PCS04 (PFC), L6599D
MainBoard: EAX61742609 (1) // EAX61742608
IC MainBoard: LGE3556C, M24C16, MX25L4005CM2I, NAND TC58NVG2S3 ..., TDA19997HL / C1, NTP-7000
Tuner: TDFR-G155D
Specifications 47LE5500
LG 47LE5500
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 47LE5500 TV does not turn on and does not show any signs of turning on, does not respond to the control buttons or to the remote control.
Most likely in this case, the main switching power supply (IIP) PLDH-L904A is faulty. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, it is necessary to check the serviceability of power switches and rectifier diodes for possible breakdown (short circuit).
In case of any breakdown of semiconductors in the secondary circuits, the converter can usually work normally in emergency short circuit mode. There are no output voltages. And during short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and less often the current sensor at the source of the key.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. Chips PWM (PWM) VIPER27H (Standby), ICE2PCS04 (PFC), L6599D are usually checked by replacing with new, or obviously working.
- There is no image, but there is sound and reaction to commands from the remote control. Or the image appears immediately after turning on and disappears.
In some of these cases, the malfunction is caused by a lack of backlighting on the display. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
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.
- 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 EAX6174260908 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). Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the elements LGE3556C, M24C16, MX25L4005CM2I, NAND TC58NVG2S3 ..., TDA19997HL / C1, NTP-7000. BGA chip malfunctions are usually easy to detect by warming up.
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 TDFR-G155D 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 TV owners! Self-repair attempts by LG 47LE5500 are not recommended by the manufacturer and can lead to serious negative consequences!
Typical defects of LG TVs with LGE3556C processors are provoked by its severe temperature conditions and the quality of the LGE3556C processor itself.
External manifestations may be different - the tuner or external inputs do not work, or the TV does not turn on, for example, the control lamp blinks or hangs on the screen saver.
If, when the processor warms up, performance is restored, in such cases a reball can sometimes help. Then there is the opportunity to extend the life of the TV with the help of an additional heat sink or cooler.

When replacing the processor, it should be borne in mind that they are discontinued and all LGE3556C, which sellers ALIexpress send, in most cases control units, are often already faulty.


Service manual and schematic diagram ------------------->  LG 47LE5500 Chassis LD03E.
CHASSIS : LD03E; MODEL: 47LE5500, 47LE550N, 47LE5500, 47LE550N-ZA, 47LE5800, 47LE5900, 47LE5800/5900-ZA, 47LE5510, 47LE5810, 47LE5510, 5810-ZB, 47LE5910, 47LE5910-ZB



 The appearance of the MainBoard EAX61742609 is shown in the figure below:
EAX61742609
EAX61742609 can be used in TVs:
LG 42LE5500 ZA (Panel LC420EUH (SC)(A1)), LG 47LE5500 ZA (Panel LC470EUH (SC)(A1)).
Main features of the device LG 47LE5500:
Installed matrix (LED-panel) LC470EUH (SC) (A1).
To power the backlight LEDs, a converter is used, combined with a power supply.
The necessary supply voltages for all nodes of the LG 47LE5500 TV are generated by the PLDH-L904A power supply module or its analogs using VIPER27H (Standby), ICE2PCS04 (PFC), L6599D microcircuits.
MainBoard - the main board (motherboard) is an EAX61742609 module, using microchips LGE3556C, M24C16, MX25L4005CM2I, NAND TC58NVG2S3 ..., TDA19997HL / C1, NTP-7000 and others.
The TDFR-G155D tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC470EUH-SCA1
Type: a-Si TFT-LCD, Panel
Diagonal size: 47 inch
Resolution: 1920x1080, FHD
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 1039.68x584.82 mm
Surface: Antiglare (Haze 10%), Hard coating (3H)
Brightness: 450 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 1.07B (8-bit + Dithering), CIE1931 72%
Response Time: 8/10 (Tr / Td)
Frequency: 120Hz
Lamp Type: WLED Without Driver
Signal Interface: Mini LVDS, 120 pins
Voltage: 12.0V