Monday, 2 March 2020

REPAIR / SERVICING TV LG 47LA644V

Technical description and composition of the LG 47LA644V TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 47LA644V 47LA644V-ZA
Chassis / Version: LD33B
Panel: LC470EUN (SF) (F2)
LED backlight: 6920L-0001C, 47 V13 Edge REV0.4 1 L-TYPE / R-TYPE
T-CON: LC470DUE-SFR1
LED driver (backlight): PCLH-D201 A-REV 0.7 6917L-0117A
Power Supply (PSU): EAX64908101 LGP4755-13P
PWM Power: L6599AD, R2A20133DSP (PFC), FSD106LG (Stb)
MOSFET Power: STD13NM60N
MainBoard: EAX64797003 (1.2)
IC MainBoard: LGE2122, SAA36403538, H5TQ4G63AFR, H5TQ2G63AFR, NTP7513
Tuner: TSQ-G601D (B) EBL61240503
Specifications 47LA644V
LG 47LA644V
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 47LA644V TV does not turn on, does not respond to the remote control and the control panel buttons, does not light up or blink indicators.
Most often, with such manifestations, the main power supply module EAX64908101 is found to be faulty. It is necessary to measure its output voltages and, if they are absent, check the power switches (STD13NM60N) and rectifier diodes for the probability of short circuit in the converters.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during short circuit in the elements of the primary circuit, the mains 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. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM) L6599AD, R2A20133DSP (PFC), FSD106LG (Stb), in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
In such cases, the most likely malfunction of the LED backlight elements. The reason can be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
It is impossible to check the LED line for breaks without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts will be required, and ideally, a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters, as a rule, light up a single 3-volt LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as a health indicator. In faulty LEDs, the 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 EAX64797003 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). Often, the MB (SSB) card must be replaced in case of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - LGE2122, SAA36403538, H5TQ4G63AFR, H5TQ2G63AFR, NTP7513 and replace failed chips with new ones. Some malfunctions may be due to the use of BGA soldering technologies in modern Main Board technologies. Typically, such defects are detected by local heating of the chip.
If the TV works normally from external devices, but does not tune into television channels, the TSQ-G601D (B) EBL61240503 tuner may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Attention to users! Self-repair of the LG 47LA644V TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!


Service manual and schematic diagram -------------->  LG 47LA644V Chassis LD33B.
CHASSIS : LD33B; MODEL : 47LA64**, 47LA64**-Z*

  LGP4755-13P EAX64908101 Power Supply schematic diagram



 The appearance of the MainBoard EAX64797003 is shown in the figure below:
EAX64797003
EAX64797003 can be used in TVs:
LG 42LA620V (Panel LC420DUE (SF)(U1)), LG 32LN570V (Panel LC320DUE (SF)(R1)), LG 50LA644V (Panel LC500EUN (SF)(F1)), LG 47LA660V (Panel LC470EUG (PF)(F1)), LG 47LA621V (Panel LC470DUE (SF)(U1)), LG 42LA644V (Panel LC420EUN (SF)(F2)), LG 39LA620V ZA (Panel T390HVJ01.0), LG 42LA621V ZD (Panel LC420DUE (SF)(U1)), LG 32LA621V ZD (Panel LC320DUE (SF)(U1)), LG 32LN655V (Panel LC320EUB (PF)(M1)), LG 42LA667V (Panel LC420EUH (PF)(P1) ), LG 47LN613V (Panel LC470DUE (SF)(R4)), LG 32LA667V ZB (Panel LC320EUB (PF)(P1)), LG 55LA660V ZA (Panel LC550EUH (PF)(P1)), LG 47LA620V ZA (Panel LC470DUE (SF)(U1)), LG 32LN613V ZB (Panel LC320DUE (SF)(R4)), LG 42LN655V ZB.BRUZLJU (Panel LC420EUH (PF)(M1)), LG 32LA644V ZA (Panel LC320EUN (SF)(F1)), LG 42LN613V (Panel LC420DUE (SF)(R4)), LG 47LA690V ZB (Panel LC47EUH (PF)(P1)), LG 47LA662V (Panel LC470EUG (PF)(F1)), LG 42LA645V 42LA645V-ZC.BRUYLJU (Panel LC420EUN (SF)(F3)), LG 32LA660V (Panel LC320EUB (PF)(P1)), LG 47LA644V 47LA644V-ZA (Panel LC470EUN (SF)(F2)), LG 50LA667S (Panel T500HVD02.1), LG 47LA691V (Panel LC470EUH (PF)(P1)), LG 32LA662V (Panel LC320EUB (PF)(P1)).
The appearance of the power supply
Main features of the device LG 47LA644V:
Installed matrix (LED-panel) LC470EUN (SF) (F2).
The matrix control uses the Timing Controller (T-CON) LC470DUE-SFR1.
To power the backlight LEDs, the PCLH-D201 LED driver is used.
The necessary supply voltages for all nodes of the LG 47LA644V TV are generated by the EAX64908101 power module or its analogs using L6599AD, R2A20133DSP (PFC), FSD106LG (Stb) microcircuits and STD13NM60N power switches.
MainBoard - the main board (motherboard) is an EAX64797003 module using LGE2122, SAA36403538, H5TQ4G63AFR, H5TQ2G63AFR, NTP7513 and other chips.
The tuner TSQ-G601D (B) EBL61240503 provides the reception of television programs and tuned to channels.
Additional technical information about the panel:
Brand: LG Display
Model: LC470EUN-SFF2
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: 350 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 16.7M (8-bit), CIE1931 68%
Response Time: 6 (G to G)
Frequency: 60Hz
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V