Technical description and composition of the LG 47LN570Y TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 47LN570Y
Chassis / Version: LB33B
Panel: LC470DUE
T-CON: LC470DUE-SFR1
LED driver (backlight): integrated into PSU; 93.2 ~ 118.5V 0.4A
PWM LED driver: BD9483F
MOSFET LED driver: MDD7N25, FDT86106
Power Supply (PSU): EAX64905501 - LGP4750-13PL2 EAY62810801
PWM Power: SSC9527S (PWM Resonant), R2A20133D (PFC), ICE3BR4765JZ (Standby)
MOSFET Power: 13NM60N
Mainboard: EAX64872104
IC MainBoard: CPU: LGE2122, DDR: K4B4G1646B
Tuner: TDSH-G501D (B)
Appearance
LG 47LN570Y
General repair guidelines for TV LCD LED
LG 47LN570Y, like other televisions, it is advisable to start repairing with a careful examination of the external and internal elements and modules. Sometimes, based on visible changes in the components of the device, it is possible to draw some conclusions and determine the direction of further troubleshooting even before the necessary measurements are taken. Elements with visible damage, for example, capacitors swelled up after boiling the electrolyte, charred resistors in certain nodes of the circuit, as well as ring cracks in solders will help the master to guess the causes and possible consequences of the malfunction.
Sometimes the LG 47LN570Y 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 LG4750-13PL2 general power supply module. If it is working properly, you need to check the processor batteries on the SSB (Main Board). 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. Possible defective PWM chip from the manufacturer.
If the LG 47LN570Y does not have an image, but there is sound, there may be a malfunction of the backlight LEDs of the LC470DUE panel or their power converter. You should also make sure that the electrolytic capacitors of the secondary rectifiers of the common power supply are working.
In most cases of lack of backlight, it becomes necessary to disassemble the panel in order to check the LEDs, connectors, loops and all contact connections. If one or several LEDs does not work in one line, therefore, they are broken and should be replaced.
When trying to detect a break in the LED lines, it should be taken into account that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.
The EAX64872104 motherboard must be checked if there is no reaction to the remote control and function buttons, the standby indicator blinks or lights up continuously. In such cases, if the converters or power regulators of the microcircuit are working, a software update may be necessary.
In some cases, to repair the MB board (SSB), it may be necessary to replace the chips - CPU: LGE2122, DDR: K4B4G1646B with new or obviously good ones. In cases where BGA technologies are used, defects are usually localized by the heating method.
If there is no reception of television channels, but the TV is working properly from external devices, first of all, check the voltage of the tuner TDSH-G501D (B).
Attention to users! Self-repair of the LG 47LN570Y TV without the appropriate qualifications and experience can lead to its complete non-repairability!
Service manual / schematic diagram ----------------> LG CHASSIS: LB33B, 47LN5700/570Y/5710, 47LN5700/570Y-TB, 47LN5710-TE SERVICE MANUAL.
psu schematic diagram ----------------> LGP4750-13PL2 EAX64905501 EAY62810801 power supply
You can reduce the backlight current in TVs with LGP4750-13PL2 power supplies (EAX64905501) as follows. Current sensors in the R811-R818 LEDs - channel 1 and R829-R836 - channel 2. Resistors in the channels in pairs of 4.3 + 3.9 Ohm. You can reduce the backlight current by 25% by removing one pair of resistors in each channel.
The appearance of the MainBoard EAX64872104 is shown in the figure below:EAX64872104
PSU Advanced
The 47LN570Y model uses the EAX64905501 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 R2A20133D PWM controller, which eliminates the charge current of the rectifier filter's electrolytic capacitor 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 47LN570Y:
Installed matrix (LED-panel) LC470DUE.
The matrix control uses the Timing Controller (T-CON) LC470DUE-SFR1.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the BD9483F PWM controller. As power elements of the LED driver, keys of the type MDD7N25, FDT86106 are used.
The necessary supply voltages for all nodes of the LG 47LN570Y TV are generated by the EAX64905501 power supply module or its analogs using SSC9527S (PWM Resonant), R2A20133D (PFC), ICE3BR4765JZ (Standby) microcircuits and 13NM60N power switches.
MainBoard - the main board (motherboard) is an EAX64872104 module, using CPU chips: LGE2122, DDR: K4B4G1646B and others.
The TDSH-G501D (B) tuner allows you to receive television programs and tune to channels.
Additional technical information about the panel:
Brand: LG Display
Model: LC470DUE-SFU2
Type: a-Si TFT-LCD, Panel
Diagonal size: 47 inch
Resolution: 1920x1080, FHD
Display Mode: IPS, Normally Black, Transmissive
Active Area: 1039.68x584.82 mm
Surface: Antiglare (Haze 1%), Hard coating (2H)
Brightness: 300 cd / m²
Contrast Ratio: 1200: 1
Display Colors: 16.7M (8-bit), CIE1931 68%
Response Time: 9 (G to G) (B / W)
Frequency: 60Hz
Lamp Type: WLED Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V
