Technical description and composition of the BBK LT1930SL TV, type of panel and applicable modules. The composition of the modules.BBK LED
Model: LT1930SL
Chassis / Version: CVMV26L-B-30
Panel: HK185WLEDM-CH31H M185B3-PA3
T-CON: M185B3-PA1 ReV.C.2 RoHS
LED driver (backlight): with integrated PSU
PWM LED driver: TL494C
MOSFET LED driver: STM6960
Power Supply (PSU): LS1906001-00GP (1008) VER5.0 Q1-SMK0460
PWM Power: PWM SOT23-6
MainBoard: CVMV26L-B-30
IC MainBoard: TSUMV26KE-LF, EN25F40-100GCP, 24C32, 24C02, TDA1517P
Tuner: F21WT-3BAR-E
Technical Specifications LT1930SL
BBK LT1930SL
General repair guidelines for TV LCD LED
Possible malfunctions
- The BBK LT1930SL 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.
In some of these cases, the main switching power supply, the LS1906001-00GP module, is found to be faulty. It is necessary to measure its output voltages and, in case of their absence, check the serviceability of power switches and rectifier diodes in the converters for possible breakdown.
In case of any breakdown of semiconductors in the secondary circuits, the converter can usually work normally in emergency short circuit mode. There are no output voltages. And with a short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and less often the current sensor at the source of the key.
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, 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.
Usually in such cases, a malfunction is detected in the backlight nodes of the LED panel. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
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 indicator blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the CVMV26L-B-30 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 - TSUMV26KE-LF, EN25F40-100GCP, 24C32, 24C02, TDA1517P 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.
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 voltages at the terminals of the F21WT-3BAR-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.
TV users and owners must remember that attempts to self-repair a BBK LT1930SL TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
FIRMWARE FOR SPI FLASH -----------> EEPROM BBK LT1930SL, Main: CVMV26L-B-30, Panel: HK185WLEDM-CH31H M185B3-PA3
The appearance of the MainBoard CVMV26L-B-30 is shown in the figure below:CVMV26L-B-30
CVMV26L-B-30 can be used in TVs:
BBK LT2230HDL (Panel HK215LEDM-PH11H CLAB215FA01), BBK LT1930SL (Panel HK185WLEDM-CH31H M185B3-PA3).
The appearance of the power supply
Main features of the BBK LT1930SL device:
The matrix (LED panel) HK185WLEDM-CH31H M185B3-PA3 is installed.
The matrix control uses the Timing Controller (T-CON) M185B3-PA1.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by a TL494C PWM controller. As power elements of the LED driver, keys of the STM6960 type are used.
The necessary supply voltages for all nodes of the BBK LT1930SL TV are generated by the LS1906001-00GP power module, or its analogs using PWM SOT23-6 microcircuits.
MainBoard - the main board (motherboard) is a CVMV26L-B-30 module, using TSUMV26KE-LF, EN25F40-100GCP, 24C32, 24C02, TDA1517P, and others microcircuits.
The F21WT-3BAR-E tuner provides television reception and channel tuning.
Brand: BBK, Model: LT1930SL.
Shortly from the TV: LCD, 720p HD, diagonal 19 "(48 cm), there is HDMI, backlight type: Edge LED.
The composition includes MainBoard CVMV26L-B-30 and LCD panel (matrix) HK185WLEDM-CH31H M185B3-PA3.
Power Supply Unit (PSU) LS1906001-00GP VER5.0 Q1-SMK0460 Power Supply.
BBK LT1930SL LED TV with HK185WLEDM-CH31H LCD, 19 "(48 cm) diagonal, 16: 9 format. The required screen brightness of 200 cd / m² is provided by LED backlighting. The ratio of maximum brightness to minimum (contrast) is 800 : 1. This model uses Edge LED backlighting, high-quality HD viewing at 1366x768 pixels is possible in the 720p (HD Ready) standard for graphic decomposition. The input high-frequency or video signal can be processed in analogue systems PAL, SECAM, NTSC Graphic Single processing and formation takes place in the digital signal standards 480i, 480p, 576i, 576p, 720p, 1080i.
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. 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, 1360x768.
The power consumed by the TV in the operating mode from the network is 40 watts.
Overall dimensions: 456x358x165 mm.
TV Weight: 4 kg.
Attention! The BBK LT1930SL LED TV panel HK185WLEDM-CH31H M185B3-PA3 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.