Technical description and composition of the BBK 40LEX-5026 TV, type of panel and applicable modules. The composition of the modules.BBK LED
Model: 40LEX-5026 / FT2C
Chassis / Version: CV338H-T42
Panel: V400HJ6-PE1
LED backlight: HY-Y395-01Y2835B10 V1 Y395-01
T-CON: V400HJ6-PE1 6B01B002YB001
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: 7R600
MainBoard: CV338H-T42
IC MainBoard: MSD6A338, MSB102KT, W25Q16DVSSIG, THGBM8G5D1KBAIL
Tuner: CDT-9NT372RF-10 (R842)
Control: RC-LEX500
Specifications 40LEX-5026 / T2C
BBK 40LEX-5026
General repair guidelines for TV LCD LED
Possible malfunctions
- BBK 40LEX-5026 does not turn on, does not respond to buttons and remote control, indicators on the front panel do not light and do not blink.
In such cases, the common power source, the AC / DC voltage converter, which is combined with the elements of the CV338H-T42 main board, is often faulty. It is then necessary to measure its output voltages and, if they are absent, you should check the power switches (7R600) and rectifier diodes of the converters for the probability of a short circuit.
In case of any breakdowns in the secondary circuits, the converter can operate in emergency short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key more often 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) PWM SOT23-6, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, but there is sound and all the other functions of the TV work. The image sometimes for a second appears immediately after turning on and disappears.
As a rule, in this case, the LED backlight turns out to be faulty. Often the cause of the malfunction is the lack of current in the LED circuit, for example, an open or short circuit, or a violation of the contact connections of the connectors.
When diagnosing, it is necessary to take into account that it is impossible to check the open in the chain of LED lines without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally, a current source. By opening the panel, each LED can be checked separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect probes in the forward direction to it. In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of health. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- The TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the CV338H-T42 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 - MSD6A338, MSB102KT, W25Q16DVSSIG, THGBM8G5D1KBAIL 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 there is no reception of television channels, but the TV works properly from external devices, first of all you need to check the power supply of the tuner CDT-9NT372RF-10 (R842) and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
TV users and owners must remember that attempts to self-repair a BBK 40LEX-5026 TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> BBK 32LEX-5024 Chassis CV338H-T42-13B
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 40LEX-5026 device:
Installed matrix (LED-panel) V400HJ6-PE1.
The matrix control uses the Timing Controller (T-CON) V400HJ6-PE1.
To power the backlight LEDs, a converter is used, combined with the main board CV338H-T42, controlled by a BIT3267 PWM controller. As power elements of the LED driver, keys of the AOD4454 type are used.
The power module is combined with the MainBoard and is designed according to a flyback AC / DC voltage converter using PWM SOT23-6 microcircuits and 7R600 type power switches.
MainBoard - the main board (motherboard) is a CV338H-T42 module, using microchips MSD6A338, MSB102KT, W25Q16DVSSIG, THGBM8G5D1KBAIL and others.
The tuner CDT-9NT372RF-10 (R842) provides the reception of television programs and tuning to channels.
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