Wednesday, 27 January 2021

REPAIRING / SERVICING TV LG 55LB652V

Technical description and composition of LG 55LB652V TV, type of panel and modules used. Module composition.

LG LED
Model: 55LB652V ZA

Chassis/Version: EAX65384004

Panel: LC550DUH (FG)(P2)

LED backlight: Direct LED 6V

LED driver (backlight): integrated into PSU

PWM LED driver: BL0202B

MOSFET LED driver: AP9561

Power Supply (PSU): EAX65423801 (2.1) LGP55-14PL2 PLDK-L309A

PWM Power: MAP8800 (PFC), FA6A01N

MOSFET Power: K7A60W

MainBoard: EAX65384004 (1.5)

IC MainBoard: CPU: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR

TDJM-G101D

Specifications 55LB652V
LG 55LB652V
General recommendations for LCD LED TV repair
Possible defects

- LG 55LB652V TV does not turn on, does not respond to the remote control and control panel buttons, indicators are not lit or blinking.

With such manifestations, in some cases the power module EAX65423801 is defective. It is necessary to measure its output voltages and in case of their absence check the serviceability of the power switches (K7A60W) and the rectifier diodes in the converters for possible breakdown.
If there is a breakdown in the secondary circuits, the inverter can usually be short-circuited, and if there is a short in the power elements of the primary circuit, the mains fuse usually blows.
Breakdown of the Mos-Fet switches used in switching sources is often caused by faults in other elements, such as in the PWM controller supply circuit, in the frequency-retaining or damping circuits, and in the Negative Feedback Stabilization circuit. PWM microcircuits MAP8800 (PFC), FA6A01N are usually checked by replacing with the new ones or with known good ones.

- No picture, sound is there, all other functions of the TV work. When turning on, the picture may sometimes appear for a second.

In such cases, the most likely cause is a malfunction in the LED panel backlighting elements. More often the cause is a breakage of LEDs, or poor contact in the connectors of strips, less often the LED-driver may be faulty.
It should be remembered that to determine the breakage in the LED lines without disassembling the panel, with a tester or multimeter is not possible without an additional device, such as a current source. To open all the PN-junctions connected in series at once a voltage of several tens of volts may be required. Then you have to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow to open the LED in the forward direction or twin LEd's are used, then the PN junction of the faulty stabilizer can indirectly serve as an indication of serviceability. If the LED is faulty, the PN junction of the stabilizer will either be open or short-circuited.

If the LG 55LB652V has no picture but has sound, often the display backlight of the LC550DUH (FG)(P2) simply does not work. Moreover, in LED-TVs usually fail LEDs inside the panel, less often the LED-driver.
In such cases you can see faintly visible image when external light hits the screen.

To replace the LEDs requires disassembly LCD-panel LC550DUH - the process requiring a master of experience and expertise. We do not recommend to perform such works by yourself to owners of TV sets and masters who have no experience in LCD-panel repair

If there is no image, but backlighting works - the screen becomes slightly lighter when the TV is turned on, and in the open TV you can see the light through the holes in the body of the panel.
In this case the panel may be defective - damage to the strips, cables, for example, as a consequence of moisture after an unsuccessful washing of the screen, the T-CON board (Timing Controller) may be defective. But quite often the MainBoard EAX65384004 is defective, and software failure is also possible.
Then first it is necessary to check the panel power supply voltage, fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within normal limits, it is necessary to trace by oscilloscope LVDS signals from MainBoard EAX65384004, as well as synchronizing signals to driver stubs.

Filled or unsuccessfully washed LED TV screens can be restored in about half of the cases, usually, if there was not significant damage in the cables and panel bars.

- The TV set does not enter the operation mode, the remote control is not responding. Front panel LED is either on continuously or is blinking.

Repair or diagnosis of motherboard EAX65384004 should begin with a check of the stabilizers and power converters necessary to power the chips and matrix. If necessary, software (software) should be updated or replaced. Often the MB board (SSB) has to be replaced if it has complex faults that are hard to detect. If you're trying to repair it, check its elements - CPU: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR and replace faulty chips with new ones. Some failures may be associated with the use of modern Main Board BGA soldering technology. Usually such defects are detected by local heating of the chip.

If the TV set is working properly from external devices, but does not tune to the TV channels, the TDJM-G101D tuner may be defective. In these cases you should first make sure that there is a supply voltage on its respective pins. You should also make sure that the tuner and the processor can communicate via the I2C bus. Sometimes the reason of the tuner malfunction may be a software error.

Warning to Users! Independent repair of LG 55LB652V TV set without the corresponding qualification and necessary experience can lead to its total unrepairability!

Repair after repair of backlight. EAX65423801 LGP55-14PL2, BL0202B. Information from the master.

Reduce backlight current from 147 mA to 125 mA - removed resistors R818 and R836 in the current sensors on the EAX65423801 board.
Driver current limitation. EAX65423801. 

General information.

You can reduce the backlight current in LG TVs with the EAX65423801 (LGP474950-14PL2) power supplies as follows. The current sensors in the LEDs R811-R818 are channel 1 and R829-R836 are channel 2. The resistors are in pairs, four pairs per channel. To reduce the backlight current by 25% you need to turn off one pair of resistors in each channel.



DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>   CHASSIS : LD42B     FOR MODELS   55LB650V, 55LB652V, 55LB653V. 



The appearance of the MainBoard EAX65384004 is shown in the figure below:






EAX65384004

The EAX6538384004 can be used in televisions:

LG 32LB650V ZE (Panel LC320DUH (FG)(P2)), LG 47LB650V ZE (Panel LC470DUH (FG) (P2)), LG 42LB650V (Panel LC420DUH (FG)(P2)), LG 42LB671V ZF (Panel LC420DUH (PG) (F1)), LG 47LB671V (Panel LC470DUH (PG)(F1)), LG 42LB653V ZK (Panel LC420DUH (FG)(P1)), LG 42LB720V (Panel LC420DUH (PG)(F1)), LG 42LB658V (Panel LC420DUH (FG)(P2)), LG 47LB677V (Panel LC470DUH (FG)(F1)), LG 42LB679V (Panel LC420DUH (PG)(F1)), LG 47LB653V (Panel LC470DUH (FG)(P1)), LG 32LB653V (Panel LC320DUH( FG)(P1)), LG 42LB690V (Panel LC420DUH (PG)(F1)), LG 55LB630V (Panel LC550DUH).


View of power supply

EAX65423801:

EAX6542423801.

The main features of the LG 55LB652V:

The matrix (LED panel) LC550DUH (FG)(P2) is installed.
To power the LED backlight used converter, combined with a power supply, controlled by the PWM controller BL0202B. AP9561 type switches are used as power elements of the LED driver.
The formation of the necessary supply voltages for all LG 55LB652V TV nodes is made by the power module EAX65423801 or its analogues using MAP8800 (PFC), FA6A01N and power switches of K7A60W type.
MainBoard - the main board (motherboard) is a module EAX65384004, using chips CPU: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR and others.
The TDJM-G101D tuner provides TV program reception and channel tuning.



Instructions and updates

There are downloadable files for the 55LB652V from the manufacturer:

Update and instruction files:
File Description File Name Type Date Size
SW File (Version 05.05.70). TV_Software_Update_Guide_v3.pdf PDF 18.07.2019 2014K update instructions
SW File (Version 05.05.70). Firmware (USB) Software_File(Version_05.05.70).zip zip 18.07.2019 674112K

Compatible with 32LB650V-ZE, 32LB650V-ZN, 32LB652V-ZA, 32LB653V-ZK, 32LB656V-ZN, 39LB650V-ZE, 39LB650V-ZN, 42LB630V-ZA, 42LB631V-ZL, 42LB639V-ZU, 42LB650V-ZE, 42LB650V-ZN, 42LB652V-ZA, 42LB653V-ZK, 42LB656V-ZN, 42LB658V-ZE, 42LB670V-ZA, 42LB671V-ZB, 42LB671V-ZF, 42LB673V-ZB, 42LB674V-ZB, 42LB676V-ZA, 42LB677V-ZC, 42LB678V-ZF, 42LB679V-ZF, 42LB679V-ZH, 42LB680V-ZD, 42LB689V-ZF, 42LB690V-ZC, 42LB700V-ZG, 42LB720V-ZG, 42LB730V-ZD, 42LB731V-ZE, 47LB630V-ZA, 47LB631V-ZL, 47LB650V-ZE, 47LB650V-ZN, 47LB652V-ZA, 47LB653V-ZK, 47LB656V-ZN, 47LB670V-ZA, 47LB671V-ZB, 47LB671V-ZF, 47LB673V-ZB, 47LB674V-ZB, 47LB676V-ZA, 47LB677V-ZC, 47LB678V-ZF, 47LB679V-ZH, 47LB680V-ZD, 47LB690V-ZC, 47LB700V-ZG, 47LB720V-ZG, 47LB730V-ZD, 47LB731V-ZE, 49JL9000-ZA, 49LB860V-ZB, 49LB870V-ZA, 50LB650V-ZE, 50LB650V-ZN, 50LB653V-ZK, 50LB670V-ZA, 50LB671V-ZB, 50LB674V-ZB, 50LB675V-ZA, 50LB676V-ZA, 50LB677V-ZC, 55JL9000-ZA, 55LB630V-ZA, 55LB631V-ZL, 55LB650V-ZN, 55LB652V-ZA, 55LB653V-ZK, 55LB656V-ZN, 55LB670V-ZA 55LB671V-ZB, 55LB671V-ZF, 55LB673V-ZB, 55LB674V-ZB, 55LB675V-ZA, 55LB676V-ZA, 55LB678V-ZF, 55LB679V-ZF, 55LB680V-ZD, 55LB690V-ZC, 55LB700V-ZG, 55LB720V-ZG, 55LB730V-ZD, 55LB731V-ZE, 55LB860V-ZB, 55LB870V-ZA, 60JL9000-ZA, 60LB650V-ZN, 60LB680V-ZD, 60LB720V-ZG, 60LB730V-ZE, 60LB860V-ZB, 60LB870V-ZA, 65LB680V-ZD, 65LB730V-ZE, 70LB650V-ZA.

Manuals and User Manuals:
File Type File Name Language Date Size
MFL68027016_05_RS.pdf English 20/01/2015 82,236K
WebOS_L_EU_11_C.zip English, Estonian, Latvian, Lettish, Lithuanian, Russian 27.05.2016 12135K
Quick start guide MBM63817892_rev02_ENG.pdf English 11.09.2015 6,311K


LG 55LB652V TV with LC550DUH (FG)(P2) LCD screen, measuring 55" (140 cm) diagonally in 16:9 aspect ratio. In the LCD-panel is implemented the principle of direct display backlighting with a rear arrangement of LEDs - Direct LED.
There is support of 3D image using passive polarization technology.
LC550DUH matrix and MainBoard software EAX65384004 provide for viewing shows and movies in high quality HD at 1920x1080 pixels in 1080p (Full HD) resolution.
The model of TV 55LB652V has built-in software (software) SMART and installed the operating system webOS. Connection to the network can be made via wireless Wi-Fi. The input analog video signal is decoded in PAL, SECAM, NTSC systems. Graphic processing of a digital signal is done in 480i, 480p, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, WMA, MPEG4, DivX, MKV, JPEG.
The sound system capacity of 20 W (2x10 W) is provided by two speakers. It uses NICAM stereo sound processing and Sound Surround surround function.
Communication with other devices via an external interface is supported by standard input and output sockets: Antenna input (RF), AV, Audio x2, Component, SCART, RGB, HDMI x3, MHL, USB x3, RS-232, Ethernet (RJ-45), Bluetooth, Wi-Fi 802.11n, WiDi, Miracast. There is a headphone jack. To connect a computer or laptop to this model of TV there is a VGA (D-Sub 15) connector. This interface supports standard resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080. The digital tuner is able to receive TV channels in the standards DVB-T, DVB-T2, DVB-C, DVB-S2.

The TV uses the EAX65423801 power supply.

Dimensions: C stand 1241x775x247 mm, without stand 1241x725x55 mm.

Warning. Panel LC550DUH LED-TV LG 55LB652V is an expensive and unreliable part of it.
Do not allow any impact on the glass and pressure on the surface of the screen to avoid damage to the LED-panel!
It is also not safe to get liquid on the screen. Sometimes one drop is enough if it drips down the glass onto the cables and the TV becomes unrepairable.