Technical description and composition of the BBK 43LEX-5056 TV, panel type and modules used. The composition of the modules.
BBK LED
Model: 43LEX-5056 / FT2C
Chassis / Version: CV338H-T42
Panel: V400HJ6-PE1
LED backlight: 3 Strings x 8 Leds 3030 3V
LED driver (backlight): integrated into MainBoard
PWM LED driver: BIT3267
MOSFET LED driver: AOD4454
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MOSFET Power: 70R380P
MainBoard: CV338H-T42
IC MainBoard: CPU: MSD6A338, MSB102KT, W25Q16DVSSIG, MP7752, VA2221TSG28 (audio), THGBM8G5D1KBAIL (EMMC FLASH)
Tuner: CDT-9NT372RF-10 (R842)
Specifications 43LEX-5056 / FT2C
BBK 43LEX-5056
General recommendations for TV LCD LED repair
Possible manifestations of defects
- BBK 43LEX-5056 does not turn on, does not respond to buttons and the remote control, indicators on the front panel do not light or flash.
In this case, first of all, you should check the operability of the main power source - the AC / DC voltage converter, all the elements of which are located on the MainBoard CV338H-T42. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches (70R380P) and rectifier diodes for possible partial or complete breakdown.
In the event of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor in the source of the key usually breaks off.
The breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM regulators (PWM) PWM SOT23-6, if they do not have visible damage to the case and an open short circuit between the pins, are usually checked by replacing.
- There is no image, there is sound, it reacts to the remote control. Or, immediately after switching on for a second, the image may appear and immediately disappear.
In some of these cases, the malfunction is caused by the lack of display backlighting. The reason may be found in the malfunction of the LEDs, in the violation of the contact connections of the LED strips 3 Strings x 8 Leds 3030 3V, or in the provision of their power supply (LED driver).
To test the LED strips, to open all the transitions of the LEDs, you need several tens of volts or more, it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED junctions in forward bias, you can sometimes detect the presence of a protective zener diode PN junction by connecting the probes in the opposite direction. If the zener diode is cut off or broken in the K / Z, then the LED is faulty and needs to be replaced.
- The TV does not turn on, the indicator signals the standby or operating mode, or blinks.
Repair or diagnostics of the CV338H-T42 motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). In cases of complex MB (SSB) repairs and with the necessary skills and equipment, it may sometimes be necessary to replace its CPU chips: MSD6A338, MSB102KT, W25Q16DVSSIG, MP7752, VA2221TSG28 (audio), THGBM8G5D1KBAIL (EMMC FLASH) and other possible faulty components. Malfunctions associated with the use of BGA soldering technologies are usually easily diagnosed by the warm-up method.
Before changing the tuner CDT-9NT372RF-10 (R842), if it is not possible to tune to TV channels, you should make sure that there are supply voltages, which must be measured at the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange between the tuner and the processor can be monitored with an oscilloscope
Owners and users of the BBK 43LEX-5056 TV should remember that self-repair without special knowledge, skills and qualifications may be fraught with negative consequences that can lead to complete non-repairability of the device!
READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.
Revision after repair of the backlight. Information from the master.
Decrease the backlight current from 510 mA to 360 mA - removed one of the 1.0 Ohm resistors in the backlight current sensor on the CV338H-T42 board. Initially, two 1.0 Ohm and two 1.5 Ohm are installed.
Driver current limitation. CV338H-T42, BIT3267S. General information.
To reduce the backlight current in LED drivers with a BIT3267 controller, increase the total resistance of the low-resistance current sensor resistors Rset connected to the INN pin 5 of the BIT3267 microcircuit.
The total resistance RLed can be calculated from the ratio RLed = 0.21 / ILed.
Sensor resistors PR182, PR183, PR203, PR238 are located next to the JW1 connector on the CV338H-T42 board. The pdf document is attached. ------------> BIT3267.
The appearance of the MainBoard CV338H-T42 is shown in the figure below:
CV338H-T42
CV338H-T42 can be used in TVs:
BBK 32LEX-5023 / T2C (Panel V320BJ6-Q01 Rev. C1 (TH32YS1705C0327)), BBK 32LEX-5024 / T2C (Panel TH32YS1704D0089).
Main features of the BBK 43LEX-5056 device:
Installed matrix (LED panel) V400HJ6-PE1.
To power the backlight LEDs, a converter combined with the CV338H-T42 main board is used, controlled by the BIT3267 PWM controller. The keys of the AOD4454 type are used as power elements of the LED driver.
The power module is combined with the MainBoard and is made according to the AC / DC flyback converter circuit using PWM SOT23-6 microcircuits and power switches of the 70R380P type.
MainBoard - the main board (motherboard) is a CV338H-T42 module, using CPU chips: MSD6A338, MSB102KT, W25Q16DVSSIG, MP7752, VA2221TSG28 (audio), THGBM8G5D1KBAIL (EMMC FLASH) and others.
Tuner CDT-9NT372RF-10 (R842) provides reception of television programs and tuning to channels.
If the BBK 43LEX-5056 / FT2C has no picture, but there is sound, often the V400HJ6-PE1 display backlight simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.
Replacing the LEDs requires disassembling the V400HJ6-PE1 LCD panel, a process that requires experience and qualifications from the technician. We do not recommend doing such work on your own to the owners of TVs and craftsmen who do not have experience in repairing LCD panels
READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.
If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light can be seen through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But the main board MainBoard CV338H-T42 often turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, the 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 the normal range, it is necessary to use an oscilloscope to trace the passage of LVDS signals from the MainBoard CV338H-T42, as well as synchronization signals to the loops with drivers.
Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.
Additional technical information about the panel:
Brand: INNOLUX
Model: V400HJ6-PE1 Rev.C2
Type: a-Si TFT-LCD, CELL
Diagonal size: 40 inch
Resolution: 1920x1080, FHD
Display Mode: MVA, Normally Black, Transmissive
Active Area: 878.112x485.352 mm
Surface: Antiglare (Haze 1%)
Glass Depth: 0.50 + 0.50 mm
Transmissivity: 6.0% (with Polarizer)
Contrast Ratio: 5000: 1
Display Colors: 16.7M (8-bit)
Response Time: 8.5 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V
LED TV BBK 43LEX-5056 / FT2C with LCD V400HJ6-PE1, diagonal size 43 "(109 cm) 16: 9. The required brightness of the screen of 250 cd / m2 is provided by LED backlighting. The ratio of maximum brightness to minimum ( contrast) is 1200: 1. The display technology of the model is implemented with LED backlighting.
The V400HJ6-PE1 sensor and MainBoard CV338H-T42 software realize high quality HD images at a resolution of 1920x1080 pixels in 1080p (Full HD) graphics.
The 43LEX-5056 / FT2C has built-in SMART software and pre-installed Android operating system. Internet connection can be made via Wi-Fi wireless connection. Supported media file formats: MP3, MPEG4, HEVC (H.265), MKV, JPEG.
Speaker power 16 W (2x8 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV x2, component, VGA, HDMI x3, USB x2, Ethernet (RJ-45), Wi-Fi 802.11n. A headphone output is provided. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C standards.
A power supply unit is used as part of the MainBoard.
Dimensions: with stand 971x611x212 mm, without stand 971x566x88 mm.
TV weight: 8.8 kg.
Attention! The V400HJ6-PE1 panel of the BBK 43LEX-5056 / FT2C LED TV is an expensive and unreliable element.
Do not allow any impacts on the glass and pressure on the surface of the screen to avoid damage to the LED-panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it flows down the glass onto the cables to make the TV unrepairable.
