Technical description and composition of the BBK 24LEM-1056 TV, panel type and applicable modules. The composition of the modules.BBK LED
Model: 24LEM-1056 / FT2C
Chassis / Version: CV512L-U24
Panel: M238HVN01.2
LED backlight: Direct LED 300mA
LED driver (backlight): integrated into MainBoard
PWM LED driver: BIT3367A
MOSFET LED driver: MMBT3904
Power Supply (PSU): integrated into MainBoard
PWM Power: LD5535
MOSFET Power: 70R900P
MainBoard: CV512L-U24
IC MainBoard: CPU: S2T512, SPI Flash: GD25Q64, Audio: RDA3118E28
Tuner: CDT-9NT372-RD60
Technical Specifications 24LEM-1056 / FT2C
BBK 24LEM-1056
General repair guidelines for TV LCD LED
Possible malfunctions
- The BBK 24LEM-1056 TV does not turn on at all. The control lights do not light or flash. The TV on the remote control and the control panel buttons do not respond.
First of all, in such cases, you should verify the operability of the common switching power supply (IIP) - AC / DC voltage converter of the mains voltage. All source elements in this TV model are located on the MainBoard CV512L-U24 main board. It is necessary to measure its output voltages and, if they are absent, check the serviceability of power switches (70R900P) and rectifier diodes in the converters for possible breakdown.
In case of breakdowns of diodes in the secondary circuits, the converter can operate in emergency short circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor at the source of the key 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) LD5535, 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 is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
In some of these cases, the malfunction is caused by a lack of backlighting on the display. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to check the line of series-connected LEDs without a special current source, and for this purpose it is not safe to use any voltage sources above 12V for them. Then it remains only to open the panel and check each LED separately. Usually, Chinese 9V-powered multimeters light up a single 3-volt LED, if you connect the probes in the forward direction, the red probe to the anode, and the black to the cathode. 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 enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly or blinks.
Repair or diagnostics of the CV512L-U24 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). Sometimes they require checking or replacing (if necessary) the elements of the MainBoard - CPU: S2T512, SPI Flash: GD25Q64, Audio: RDA3118E28. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
In the absence of tuning to the channels of on-air or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltage at the terminals of the tuner CDT-9NT372-RD60. It is also necessary to check the presence of pulses of data exchange between the tuner and the processor via the I2C bus using an oscilloscope.
Once again, remind users! Attempts to self-repair a BBK 24LEM-1056 TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> Main CV512L-U24
FIRMWARE FOR SPI FLASH -----------> BBK 24LEM-1056/FT2C, Main: CV512L-U24, Panel: M238HVN01.2
The appearance of the MainBoard CV512L-U24 is shown in the figure below:CV512L-U24
Main features of the BBK 24LEM-1056 device:
Installed matrix (LED-panel) M238HVN01.2.
To power the backlight LEDs, a converter is used, combined with the main board CV512L-U24, controlled by the BIT3367A PWM controller. As power elements of the LED driver, keys of the type MMBT3904 are used.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter using LD5535 microcircuits and power switches of the type 70R900P.
MainBoard - the main board (motherboard) is a CV512L-U24 module, using CPU chips: S2T512, SPI Flash: GD25Q64, Audio: RDA3118E28 and others.
The tuner CDT-9NT372-RD60 provides the reception of television programs and tuning to channels.
BBK 24LEM-1056 / FT2C LED TV with M238HVN01.2 LCD, 23.6 "(60 cm) diagonal size of 16: 9 format. The required screen brightness of 200 cd / m² is provided by LED backlighting. The ratio of maximum brightness to minimum ( contrast ratio) is 3000: 1. The LED display technology is implemented in the model’s display technology. The design and technical capabilities of the TV include watching programs and movies in high quality HD at a resolution of 1920x1080 pixels in a graphical resolution according to the standard 1080p (Full HD). s multimedia files: MP3, WMA, MPEG4, DivX, MKV, JPEG.
The power of the sound system 10 W (2x5 W) provide two speakers. The audio processing system NICAM STEREO is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, component, VGA, HDMI, USB. An output for connecting headphones is provided. A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
The power consumed by the TV in the operating mode from the network is 36 watts.
Overall dimensions: with a support of 557x367x165 mm, without a support of 557x332x86 mm.
The mass of the TV: 2.2 kg.
Attention! The M238HVN01.2 panel of the BBK 24LEM-1056 / FT2C LED TV is an expensive and unreliable element.
Avoid any impact on the glass and pressure on the surface of the screen to avoid damage to the LED panel!
It is also unsafe to get liquid on the screen. Sometimes one drop is enough if it flows down the glass onto the cables so that the TV becomes unrepairable.
