Technical description and composition of the BBK LEM1981 TV, panel type and applicable modules. The composition of the modules.BBK LED
Model: LEM1981
Chassis / Version: 228-120615001 MST6M1xx
Panel: V185B1-L17 Rev. C1 CMO
LED driver (backlight): M14 A32275 15 mono board
Power Supply (PSU): M14 A32275 15
MainBoard: M14 A32275 15 // MSDV3213-ZC01-01 G A233342
IC MainBoard: RT8296AH, AB2E0, M3005S, PT2308S, SY8008B
Tuner: F35WT-2A-E
Control: RC-LEM101
Technical Specifications LEM1981DT
BBK LEM1981
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The BBK LEM1981 TV does not turn on and does not show any signs of turning on. There are no reactions to the control buttons or the remote control.
With such manifestations, in most cases, the M14 power module is faulty. It is necessary to measure its secondary output voltages, 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.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, power, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. The PWM chip can also cause a malfunction of the power switch of the converter and is checked by replacement.
- 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
As a rule, in such cases there is no display backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It should be remembered that it is not possible to determine the open circuit in the LED lines without disassembling the panels with a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required. Then it is necessary to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow you to open the LED in the forward direction or dual LEd are used, then the PN junction of the emergency zener diode can indirectly serve as a health indicator. In case of LED-a failure, the zener diode PN junction will either be cut off or broken into short-circuit.
- The indicator blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
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). Sometimes it is necessary to check or replace (if necessary) the elements of the MainBoard board - RT8296AH, AB2E0, M3005S, PT2308S, SY8008B. In cases where the BGA processor is used, its malfunction is usually detected by local heating.
If you suspect a malfunction of the F35WT-2A-E tuner, first of all, it is necessary to verify the correctness of the software, as well as the presence of the necessary voltage levels and impulses of data exchange with the processor via the I2C bus at the corresponding terminals of the tuner.
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Entrust repair to professionals with sufficient experience in the field of repair of electronic equipment.
Schematic Diagrams 12 pages of 2011 on LEM1981DT, LEM2281FDT, LEM2465DTG, LEM2481FDT, LEM2648DT, LEM2649FTD, LEM2665FDTG, LEM2681FDT, LEM3248DT, LEM3249FDT, LEM3281FDT
The appearance of the MainBoard MSDV3213-ZC01-01 is shown in the figure below:MSDV3213-ZC01-01
Main features of the BBK LEM1981 device:
Installed matrix (LED-panel) V185B1-L17 Rev. C1 CMO.
The LED driver M14 is used to power the backlight LEDs.
The formation of the necessary supply voltages for all nodes of the BBK LEM1981 TV is carried out by the M14 power module, or its analogues.
MainBoard - the main board (motherboard) is an M14 module, using chips RT8296AH, AB2E0, M3005S, PT2308S, SY8008B and others.
The F35WT-2A-E tuner provides television reception and channel tuning.
BBK LEM1981DT LED TV with HT185WX6-100 LCD, 19 "(48 cm) diagonal, 16: 9 format. The required screen brightness of 250 cd / m² is provided by LED backlighting. The ratio of maximum brightness to minimum (contrast) is 800 : 1. This model uses edge LED backlighting. It is possible to view images in high quality HD at a resolution of 1366x768 pixels in the standard for graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC . Graphic I process and generate digital signal in the 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 30 watts.
Dimensions: With stand 451x325x150 mm, Without stand 451x284x43 mm.
TV Weight: 2.8 kg.
Attention! The BB18 LEM1981DT LED TV panel HT185WX6-100 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.
