Technical description and composition of the BBK LT1929S TV, panel type and applicable modules. The composition of the modules.BBK
Model: LT1929S
Chassis / Version: MSTV2203-ZC01-01
Panel: F21WT-3BAR-E
Lamp backlight: CCFL
T-CON: 185WA03S
Inverter (backlight): integrated into PSU
PWM Inverter: BIT3102B
MOSFET Inverter: AO4435, AO4804
Power Supply (PSU): TV1901-ZC02-01B
PWM Power: DM0565R
MainBoard: MSTV2203-ZC01-01 (B)
IC MainBoard: TSUMV26KU-LF, 24C32, MX25L4005A, NT71209FG-809
Tuner: F21WT-3BAR-E
Control: Remote: RC3229
Technical Specifications LT1929S
BBK LT1929S
General recommendations for repairing TV LCD
Possible manifestations of defects
- BBK LT1929S TV does not turn on, does not respond to the remote control and control panel buttons, indicators do not light up and do not blink.
In such cases, the malfunction should be sought first in the TV1901-ZC02-01B power supply module. It is necessary to verify the presence of its output voltages and, if they are completely absent, check the power switches and rectifier diodes for a probable short circuit.
In the event of breakdowns in the secondary circuits of the converter, it can usually fail in short circuit mode, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse or current sensor at the source of the key most often 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. 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) DM0565R, 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 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 indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the MSTV2203-ZC01-01 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). Complex repair of MB (SSB) is possible only in the conditions of a service center with the necessary equipment. Testing or replacing elements TSUMV26KU-LF, 24C32, MX25L4005A, NT71209FG-809 requires the necessary training and professional skills in repairing modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by warming up.
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 LT1929S TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
Service Manual / Schematic Diagram ------------------> (Main Board) MYSTERY MSTV2203-N1
The appearance and voltage measurements at the control points of MainBoard MSTV2203-ZC01-01 are shown in the figure below:MSTV2203-ZC01-01
MSTV2203-ZC01-01 can be used in TVs:
BBK LT1929S (Panel F21WT-3BAR-E), BBK LT1529S (Panel M156MWR1), MYSTERY MTV-2206W (Panel CLAA216WA01), MYSTERY MTV-1906W (Panel M190MWW3), MYSTERY MTV-1607w (Panel M156MWR1), MYSTERY MTV-1907W (Panel BOE HT185WX2-10), MYSTERY MTV-2417WHD (Panel M236MWF1), MYSTERY MTV-2407WH (Panel V236H1-L05 Rev:C1), MYSTERY MTV-2217WD (Panel CLAA215FA05), MYSTERY MTV-1917WD (Panel CLAA185WA06).
The appearance of the power supply
Main features of the BBK LT1929S device:
The matrix (LCD panel) F21WT-3BAR-E is installed.
The matrix control uses the Timing Controller (T-CON) 185WA03S.
To power the backlight, a converter is used, combined with a power supply, controlled by a BIT3102B PWM controller. As power elements of the inverter, keys of the type AO4435, AO4804 are used.
The necessary supply voltages for all nodes of the TV BBK LT1929S are generated by the TV1901-ZC02-01B power supply module or its analogs using DM0565R microcircuits.
MainBoard - the main board (motherboard) is a module MSTV2203-ZC01-01, using chips TSUMV26KU-LF, 24C32, MX25L4005A, NT71209FG-809 and others.
The F21WT-3BAR-E tuner provides television reception and channel tuning.
BBK LT1929S LCD TV with F21WT-3BAR-E LCD, 19 "(48 cm) diagonal, 16: 9 aspect ratio. 250 cd / m² screen brightness is provided by CCFL (EEFL) fluorescent lamps. Maximum brightness to minimum ratio (contrast ratio) is 1000: 1. You can view images in high quality HD at a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and digital generation signal occurs in standard The channels are 480i, 480p, 576i, 576p, 720p, 1080i.
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, component, SCART, RGB, VGA, HDMI. 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, 1280x1024.
The power consumed by the TV in the operating mode from the network is 30 watts.
Overall dimensions: With stand 460x346x140 mm, Without stand 460x310x71 mm.
TV Weight: 3.8 kg.
Attention! The BB21 LT1929S LCD TV panel F21WT-3BAR-E is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!