Technical description and composition of the BBK 50LEX-5056 TV, panel type and applicable modules. The composition of the modules.BBK LED
Model: 50LEX-5056 / FT2C
Chassis / Version: CV338H-T50
Panel: CX500DLEDM
LED backlight: HL-00500A30-0901S-04 30805HL050660Z03
T-CON: T500HVN08.5 XL 50T20-S08
LED driver (backlight): integrated into MainBoard
Power Supply (PSU): integrated into MainBoard
PWM Power: PFC & PWM SOT23-6
MainBoard: CV338H-T50
IC MainBoard: Audio: MP7752
Control: IR: 0.E00-LE50660-0H
Technical Specifications 49LEX-5048 / FT2C
BBK 50LEX-5056
General repair guidelines for TV LCD LED
Possible manifestations of defects
- BBK 50LEX-5056 does not turn on, the indicators on the front panel do not light or flash. The TV does not respond to the control buttons and the remote control.
The malfunction in such cases, first of all, should be sought in the power elements of a switching power supply (IIP) - a network voltage converter (AC / DC), which in this TV model is combined with the MainBoard CV338H-T50 main board. It is necessary to measure its output supply voltages, and in case of their absence, check the serviceability of the power switches of the converters and rectifier diodes for the probability of breakdown in PN semiconductor junctions.
In the event of breakdowns in the secondary circuits of the converter, it can usually fail in short circuit mode, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse or current sensor at the source of the key most often breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM PFC & PWM SOT23-6 chips are usually checked by replacing with new ones, or obviously working.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it on and immediately disappears
In such cases, the most likely malfunction of the LED backlight elements. The reason can be both in the power of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
To check the health in the LED circuit, it is better to use a current source with a maximum voltage of 200V. We do not recommend using any voltage sources for this purpose. You can check each LED individually with a simple Chinese multimeter (powered by 9 volts) in the P-N-junction test mode. If you connect the red probe of the multimeter to the anode of the LED, and the black to its cathode, then the 3-volt LED will light up slightly, and in the opposite direction you can detect the transition of the emergency zener diode. A zener diode PN junction indirectly indicates a LED-a
- 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 CV338H-T50 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). Board repair and replacement of Audio: MP7752 microcircuits are carried out with the necessary equipment, and the corresponding element base. Faults associated with the application of BGA processor soldering technologies can be localized by the heating method.
It should be remembered! Attempts to independently repair the BBK 50LEX-5056 TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!
The appearance of the MainBoard CV338H-T50 is shown in the figure below:CV338H-T50
The appearance of the power supply
Main features of the BBK 50LEX-5056 device:
Installed matrix (LED-panel) CX500DLEDM.
The matrix control uses the Timing Controller (T-CON) T500HVN08.5.
To power the backlight LEDs, a converter is used, combined with the main board CV338H-T50.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit using PFC & PWM SOT23-6 microcircuits.
MainBoard - the main board (motherboard) is a CV338H-T50 module, using Audio chips: MP7752 and others.