Technical description and composition of the BBK LD2424HDU TV, type of panel and applicable modules. The composition of the modules.BBK
Model: LD2424HDU
Panel: HT235F01-100 // M236H1-L01 Rev. C1
Inverter (backlight): integrated into PSU
PWM Inverter: TL494C (16)
MOSFET Inverter: ME4946 (8)
Trans Inverter: AYT-005 100208
Power Supply (PSU): AYL220426 3BS0009214
PWM Power: G135 (PWM SOT23-6)
MainBoard: B.SPC81B-1 9245
IC MainBoard: TDA1517P
Tuner: TDQ-6F6 / T126CW
Control: RC1524
Technical Specifications LD2424HDU
BBK LD2424HDU
General recommendations for repairing TV LCD
Possible malfunctions
- The BBK LD2424HDU TV does not turn on, does not respond to the remote control and the control panel buttons, and does not blink with any indicators.
Most likely in this case, the main switching power supply (IPS) AYL220426 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 supply, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. The PWM microcircuit (PWM) G135 (PWM SOT23-6) can also cause a malfunction of the power switch of the converter and is checked by replacement.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
The defect can be caused by problems in the nodes or elements of the backlight of the display, or in the power supply of the lamps or inverter. If all the electrolytic capacitors of the filter according to the power supply of the inverter are working, make sure that the lamps are working, then you need to check the converter keys and the secondary windings of the transformers.
If in diagnosing a malfunction, it is necessary to disable the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required during work, and after they are finished, it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- The TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the B.SPC81B-1 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 cases of attempts to repair the MB board (SSB), it is necessary to check the serviceability of its elements - TDA1517P which may require replacement with new ones. If a BGA processor is installed, there is a possibility of a violation of the soldering of the contacts of its conclusions with the board (it is diagnosed by heating).
Before changing the tuner TDQ-6F6 / T126CW, if it is not possible to tune to television channels, make sure that there are supply voltages that need to be measured on the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
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.
The appearance of the MainBoard B.SPC81B-1 is shown in the figure below:B.SPC81B-1
B.SPC81B-1 can be used in TVs:
AKAI LTC-15S04 LTC-15S04M (Panel LTA150XH-L06), BBK LD2424HDU (Panel HT235F01-100), FUSION FLTV-19W6 (Panel M190A1-P0A), FUSION FLTV-22W6 (Panel CLAA215FA), IZUMI TL22F405R (Panel M215HW01 V.0), IZUMI TL22F405B (Panel M215HW01 V.0), IZUMI TL19H405B (Panel M190MWW3).
The appearance of the power supply
Main features of the BBK LD2424HDU device:
Installed matrix (LCD panel) HT235F01-100 or M236H1-L01 Rev. C1.
To power the backlight, a converter is used, combined with a power supply, controlled by a TL494C PWM controller (16). AYT-005 100208 transformer is installed in the inverter converter. Keys of type ME4946 (8) are used as power elements of the inverter.
The necessary supply voltages for all nodes of the BBK LD2424HDU TV are generated by the AYL220426 power module or its analogs using G135 microcircuits (PWM SOT23-6).
MainBoard - the main board (motherboard) is a B.SPC81B-1 module, using TDA1517P chips and others.
The TDQ-6F6 / T126CW tuner provides TV reception and channel tuning.
Brand: BBK, Model: LD2424HDU.
Shortly from the TV: LCD, 1080p Full HD, diagonal 24 "(61 cm), there is HDMI, there is USB.
The composition uses MainBoard B.SPC81B-1 9245 and an LCD panel (matrix) HT235F01-100, or M236H1-L01 Rev. C1.
Power Supply Unit (PSU) AYL220426 3BS0009214 Power Supply.
BBK LD2424HDU LCD TV with HT235F01-100 LCD, 24 "(61 cm) diagonal size in 16: 9 format. 300 cd / m² screen brightness is provided by CCFL (EEFL) fluorescent lamps. Maximum brightness to minimum ratio (contrast) ) is 1000: 1. The design and technical capabilities of the TV provide for viewing broadcasts and films in high quality HD at a resolution of 1920x1080 pixels in graphic decomposition according to the standard 1080p (Full HD). The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC Graphic th processing and the formation of the digital signal is in 480i standards, 480p, 576i, 576p, 720p, 1080i, 1080p Supported multimedia file formats:. MP3, WMA, MPEG4, VideoCD, SVCD, Picture CD, JPEG.
The power of the sound system 3 W (2x1.5 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, S-Video, SCART, RGB, VGA, HDMI, 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 power consumed by the TV in the operating mode from the network is 60 watts.
Overall dimensions: 585x430x200 mm.
TV Weight: 5.7 kg.
Attention! The BB23 LD2424HDU LCD TV panel HT235F01-100 is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!
Lack of image when there is a signal at BBK LD2424HDU is often caused by a malfunction of the backlight. Moreover, the problem can be both inside the LCD panel (matrix) HT235F01-100, for example, a malfunction of the CCFL lamps (EEFL), and outside in the power source - the inverter.
Without backlighting, you can sometimes see a barely noticeable image with a certain successful hit of external lighting on the screen.
Often, repairing the backlight requires disassembling the LCD panel HT235F01-100 - a painstaking process that requires increased attention and accuracy from the master. In such cases, it is possible, at the slightest negligence, to damage the glass or cables and the TV may become unrepairable.
Strongly do not recommend doing such work to TV owners and craftsmen who do not have experience in repairing LCD panels! Moreover, at home (at home from the owner).
If there is no image if there is a backlight, the screen becomes a little lighter when you turn it on, and if the TV is open, the light from the lamps is visible through the holes in the panel body.
In this case, the malfunction can be inside the panel, damage to the strips, loops, the T-CON (Timing Controller) board may be malfunctioning. But often the MainBoard B.SPC81B-1 main board also turns out to be faulty, and a software failure is also possible.
In such cases, the master first of all needs to check the main voltage of the panel on the LVDS connector, the fuses on the T-CON board or panel strips, as well as the supply and reference voltages for line and column drivers - VGH, VGL, Vcom.
If all the above measurements are within normal limits, then the oscilloscope needs to track the passage of LVDS signals from the MainBoard B.SPC81B-1, as well as the synchronizing signals from T-CON to the loops with drivers ..
