Technical description and composition of the LG 47LA790V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 47LA790V
Chassis / Version: LD34D
Panel: LC470EUH (LF) (F1)
LED backlight: 6922L-0067A, 47 V13 APT TV REV 0.4 1 L-Type / R-Type 6920L-0001C
LED driver (backlight): integrated into PSU; 67.2V, 0.9A
PWM LED driver: R5F100BCAFP, IW7011
MOSFET LED driver: TK15A20D
Power Supply (PSU): EAX64905701 (2.5), EAY62810901, LGP4247-13LPB
PWM Power: SSC9527S (PWM Resonant), R2A20133D (PFC), ICE3BR4765JZ (Standby)
MOSFET Power: 13NM60N, 10NM60N
MainBoard: EAX65040104-1.1 - EBR77153001 - SAA36549634, SAA36549406
IC MainBoard: LG1154AN, H5TQ4G63AFR,
Tuner: TDSQ-G651D (B)
Control: IR: EBR76405602, Wi-Fi: EAT61813901 TWFM-B006D BEJTWFMB006D
Specifications 47LA790V
LG 47LA790V
General repair guidelines for TV LCD LED
If the 47LA790V TV does not turn on, does not make any sounds when turned on, and also no indicators on the front panel light or blink - there is a high probability of a malfunction in the power module. In some cases, there may be a malfunction only in standby power. In the general case, first of all, it is necessary to check the electrolytic capacitors of the secondary rectifier filters and the fuse at the input of the network. If it is cut off, then it is necessary to check the rectifier bridge diodes and the key transistor of the converter for a breakdown of the PN junctions, which can either be on a separate radiator or integrated with a PWM controller in a common chip. Options are 13NM60N, 10NM60N.
The breakdown of the power switch of the pulse converter is often triggered by other elements, for example, in the stabilization or control circuits of this switch, as well as by the damper elements in its drain and TPI winding.
If the LG 47LA790V does not have an image, there is sound and the channels are switched, there is a possibility of a malfunction in the backlight LED circuit of the LC470EUH (LF) (F1) panel, or their power converter - LED driver. Sometimes, when turned on, the image appears and immediately disappears. In such cases, it is necessary to check the electrolytic capacitors of the power filter of the backlight unit.
A malfunction in the backlight circuits often occurs due to an open in the power circuit of the LED lines. It requires disassembling the panel and checking the LEDs themselves, the rations of their terminals, as well as the reliability of the connections in the connectors and rations of the terminals.
To open all transitions, several tens of volts or more are necessary, and it is best to use a current source for such purposes. A break in the line of LEDs connected in series cannot be detected with a multimeter or tester without disassembling the panel. In the open panel, it is necessary to check each LED. If your multimeter cannot open the LED transitions in forward bias, then see the presence of the PN transition 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.
If the motherboard EAX65040104-1.1 - EBR77153001 - SAA36549634, SAA36549406 is faulty, first of all it is necessary to check all the linear stabilizers and power converters of its chips, and also, if necessary, update the software (software). Sometimes you can check the health of MB only by replacement.
In some cases, they require checking or replacing (if necessary) the elements of the MB board (SSB) - LG1154AN, H5TQ4G63AFR,. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
Before changing the TDSQ-G651D (B) tuner, if it is not possible to tune to television channels, make sure that there are supply voltages that must be measured on the corresponding tuner pins and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Remember! Attempts to self-repair by users of the LG 47LA790V TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
Service manual and schematic diagram --------------> LG 47LA790V Chassis LD34D.
CHASSIS : LD34D; MODEL: 47LA790V/W/9, 47LA790V/W/9-ZA
PSU schematic diagram --------------> LGP4247-13LPB
The appearance of the MainBoard EAX65040104-1.1 is shown in the figure below:EAX65040104-1.1
PSU Advanced
The 47LA790V model uses the EAX64905701 power supply unit using the PFC (Power Factor Correction) node - an active filter of the highest harmonics of the current consumption. In fact, it is a boost converter based on the R2A20133D 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 47LA790V:
Installed matrix (LED-panel) LC470EUH (LF) (F1).
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by a PWM controller R5F100BCAFP, IW7011. As the power elements of the LED driver, keys of the TK15A20D type are used.
The necessary supply voltages for all nodes of the LG 47LA790V TV are generated by the EAX64905701 power supply module or its analogs using SSC9527S (PWM Resonant), R2A20133D (PFC), ICE3BR4765JZ (Standby) microcircuits, and 13NM60N, 10NM60N power switches.
MainBoard - the main board (motherboard) is an EAX65040104-1.1 module, using chips LG1154AN, H5TQ4G63AFR, and others.
The TDSQ-G651D (B) tuner allows you to receive television programs and tune to channels.
Additional technical information about the panel:
Brand: LG Display
Model: LC470EUH-LFF1
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 1%), Hard coating (2H)
Brightness: 400 cd / m²
Contrast Ratio: 1500: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 8/10 (Tr / Td)
Frequency: 120Hz
Lamp Type: WLED Without Driver
Signal Interface: EPI, 100 pins
Voltage: 12.0V