Technical description and composition of the BBK LD1906SI TV, type of panel and applicable modules. The composition of the modules.BBK
Model: LD1906SI
Panel: SVA190WX02TB
Inverter (backlight): 5INV403-2 rm0742-2 v2.1 4lamp
PWM Inverter: MP1008ES (pl16n)
Trans Inverter: CAY T-3404 0742
Power Supply (PSU): Adapter AK083 12V 4.5A
PWM Power: 1377B (8)
MOSFET Power: BA641 PL
MainBoard: 21903-7 2007.08.29.zmw // 21901-2
IC MainBoard: MST718BU-LF, SPI FLASH: Pm25LV020, EEPROM: 24C32
Tuner: JS-6H2 / T121
Control: LT115
Technical Specifications LD1906SI
BBK LD1906SI
General recommendations for repairing TV LCD
Possible malfunctions
- The BBK LD1906SI TV does not turn on, does not respond to the remote control and the control panel buttons, the indicators do not light or flash.
With such manifestations, a malfunction is most likely to be detected in the Adapter power module.
This TV model is equipped with an external power adapter adapter AK083 12V 4.5A, which the owner can purchase on their own, and repairing it may not always be advisable, however, sometimes it makes sense to open it and eliminate simple typical defects typical of IPS. It is necessary to measure its secondary output voltages, and if they are absent, check the operability of the power switches (BA641 pl) 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 1377B (8). It is checked only by replacement with a known good one.
- 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
These manifestations can be triggered by a power module, or by defects in the inverter, as well as a distortion of the currents in the lamps due to their uneven wear. After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, it is necessary to ring in its converter the power switches for breakdown and the secondary windings of transformers for an open.
Sometimes, for diagnostic purposes, it is necessary to disable the inverter protection. In such cases, special care must be taken during work, and the protection circuits should be restored immediately after the repair is completed.
- 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 21903-7 motherboard should begin by checking the stabilizers and power converters needed to power the microcircuit and matrix. If necessary, update or replace the software (software). Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the elements MST718BU-LF, SPI FLASH: Pm25LV020, EEPROM: 24C32. BGA chip malfunctions are usually easy to detect by warming up.
If a JS-6H2 / T121 tuner is suspected of malfunction, first of all, it is necessary to verify the correctness of the software, as well as the presence of the necessary supply voltage levels and data exchange pulses with the processor via the I2C bus on the corresponding tuner pins.
We recommend the owners of the LD1906SI TV for repair only to qualified specialists with the necessary work experience! Self-repair attempts without the appropriate knowledge and skills can lead to irreversible negative consequences!
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> BBK LT1500S-2, LT1500S-3, LD1506SI-2, LD1506SI-3, LT1900S, LD1906SI, LT2000S, LD2006SI-2
Service Manual with Schematic Diagram 168 pages 2006 model LD2006SI-2, LD1506SI-2, LD1506SI-3, LT1500S-2, LT1500S-3, LT2000S, LD1906SI, LT1900S.
The appearance of MainBoard 21903-7 is shown in the figure below:21903-7
21903-7 can be used in TVs:
BBK LD1906SI (Panel SVA190WX02TB), BBK LT2000S (Panel A201SN02).
Main features of the BBK LD1906SI device:
Installed matrix (LCD panel) SVA190WX02TB.
To power the backlight, an inverter 5INV403-2 is used, it is controlled by the PWM controller MP1008ES (pl16n). A transformer CAY T-3404 0742 is installed in the inverter converter.
To power all the internal components of the BBK LD1906SI TV, an external adapter type AK083 12V 4.5A is used with 1377B microcircuits (8) and power switches of type BA641 pl.
MainBoard - the main board (motherboard) is a module 21903-7, using microchips MST718BU-LF, SPI FLASH: Pm25LV020, EEPROM: 24C32 and others.
The tuner JS-6H2 / T121 provides the reception of television programs and tuning to channels.
Information from an alternative source:
TV & DVD BBK LD1906SI
Panel Type (Matrix): SVA190WX02TB REV: A
Motherboard: 21903-6 V3.01, MT1389FE 0734-HEAL, S29Al016D70FP, HY57V641620FTP, BA5954FP, PH3SD, HEF4052BT, atmel 24c16, atmel 24c32, NEF4094BT
Invertor: 5INV403-2, POWER: DC + 12V
Additional technical information about the panel:
Brand: SVA-NEC
Model: SVA190WX02TB
Type: a-Si TFT-LCD, Panel
Diagonal size: 19.0 inch
Resolution: 1440x900, WXGA +
Display Mode: TN, Normally White, Transmissive
Active Area: 408.24x255.15 mm
Brightness: 300 cd / m²
Contrast Ratio: 800: 1
Display Colors: 16.7M (6-bit + Hi-FRC), CIE1931 72%
Response Time: 1.3 / 3.7 (Tr / Td)
Frequency: 60Hz
Lamp Type: 4 pcs CCFL Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 30 pins
Voltage: 5.0V
Brand: BBK, Model: LD1906SI.
Shortly from the TV: LCD, diagonal 19 "(48 cm), USB connectors: 2.
The composition uses MainBoard 21903-7, or 21901-2 and the LCD panel (matrix) SVA190WX02TB.
Power supply unit external Adapter AK083 12V 4.5A.
BBK LD1906SI LCD TV with SVA190WX02TB LCD, 19 "(48 cm) diagonal 16:10 aspect ratio. 300 cd / m² screen brightness is provided by CCFL (EEFL) fluorescent lamps. The ratio of maximum brightness to minimum (contrast) is 700: 1. The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in standards 480i, 480p, 576i, 576p. Supported media file formats: MP3, WMA, MPEG4, VideoCD, SVCD, Picture CD, JPEG.
The power of the sound system 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, USB x2. 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 54 watts.
Overall dimensions: With stand 738x495x220 mm, Without stand 498x371x83 mm.
Attention! The BBA LD1906SI LCD TV panel SVA190WX02TB is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!