Technical description and composition of the BBK LEM2281F TV, type of panel and applicable modules. The composition of the modules.BBK LED
Model: LEM2281F
Chassis / Version: 228-120615002
Panel: M215HG-LE4 Rev C3
LED driver (backlight): integrated into MainBoard
Power Supply (PSU): integrated into MainBoard
MainBoard: M14 / A32276 / 15 mono board
Tuner: F35WT-2A-E
Control: RC-LEM101
Technical Specifications LEM2281FDT
BBK LEM2281F
General repair guidelines for TV LCD LED
Possible malfunctions
- The BBK LEM2281F TV does not turn on, and generally does not show any signs of turning on. There are no reactions to the control buttons and the remote control.
Often in such cases, the main power source, the AC / DC voltage converter, which is combined with the MainBoard M14 board, is faulty. It is necessary to measure the secondary output voltage, and in case of their absence, check the serviceability of the power switches of the converters and rectifier diodes for a short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during short circuit in the elements of the primary circuit, the mains fuse 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. It can be supply, damper circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power switch may be PWM (PWM). It is checked only by replacement with a known good one.
- There is no image, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
In most of these cases, a malfunction is detected in the nodes and backlight elements of the LED panel. 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.
It is impossible to detect a break in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect the probes in the forward direction to it (red probe to the anode, 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 turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the M14 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).
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 F35WT-2A-E tuner. 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.
Attention TV owners! Attempts at self-repair of BBK LEM2281F are not recommended by the manufacturer and can lead to serious negative consequences!
Schematic Diagrams 12 pages of 2011 on LEM1981DT, LEM2281FDT, LEM2465DTG, LEM2481FDT, LEM2648DT, LEM2649FTD, LEM2665FDTG, LEM2681FDT, LEM3248DT, LEM3249FDT, LEM3281FDT
Main features of the BBK LEM2281F device:
Installed matrix (LED-panel) M215HG-LE4 Rev C3.
To power the backlight LEDs, a converter is used, combined with the main board M14.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit.
MainBoard - the main board (motherboard) is an M14 module.
The F35WT-2A-E tuner provides television reception and channel tuning.
BBK LEM2281FDT LED TV with CLAA215FA10 LCD display, diagonal size 22 "(56 cm) in 16: 9 format. The required screen brightness of 250 cd / m² is provided by LED backlight LED. The ratio of maximum brightness to minimum (contrast) is 800: 1 This model uses side illumination from Edge LEDs.The design and technical capabilities of the TV include watching programs and movies in high quality HD with a resolution of 1920x1080 pixels in graphic resolution according to the standard 1080p (Full HD). Input high-frequency or video signal l can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, WMA, MPEG4, MKV, JPEG .
The power of the acoustic system of sound 6 W (2x3 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, SCART, RGB, VGA, HDMI x2, USB. An output for connecting headphones is provided. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector is used on the TV case, this interface supports resolutions: 640x480, 800x600, 1024x768. The digital tuner is capable of receiving television channels in DVB-T MPEG4 standards.
The power consumed by the TV in the operating mode from the network is 38 watts.
Overall dimensions: With a support 518x363x160 mm, Without a support 518x322x50 mm.
TV Weight: 3.8 kg.
Attention! The CLAA215FA10 panel of the BBK LEM2281FDT 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.