Monday, 27 July 2020

REPAIR / SERVICING TV SUPRA STV-LC50LT0010F

Technical description and composition of the SUPRA STV-LC50LT0010F TV, panel type and modules used. The composition of the modules.
SUPRA LED
Model: STV-LC50LT0010F
Chassis / Version: V1S10
Panel: K490WDC1
LED driver (backlight): integrated into MainBoard
PWM LED driver: MP4653
MOSFET LED driver: 7N65, AOD4504
Power Supply (PSU): integrated into MainBoard
PWM Power: FA5696, LNK6777, MP4653
MOSFET Power: FMV13N60S1, 7N65
MainBoard: MSD3463-T8D1
IC MainBoard: CPU: MSD3463SGA, SPI Flash: MX25L6406E, AUDIO: TPA3110LD2
Tuner: ST43WS-2A-E (Si2151)
STV-LC50LT0010F Specifications
SUPRA STV-LC50LT0010F
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- SUPRA STV-LC50LT0010F does not turn on, indicators on the front panel are not lit or blinking. The TV does not respond to control buttons and the remote control.
In this case, the main Switching Power Supply (AC / DC voltage converter), the elements of which are located on the MainBoard MSD3463-T8D1 main board, may be faulty. It is necessary to measure its output voltages, and if they are absent (full or partial), the serviceability of the power switches (FMV13N60S1, 7N65) of the converters and rectifier diodes should be checked for a possible short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in a short-circuit mode, and in case of a short circuit in the elements of the primary circuit, the mains fuse is usually cut off.
Mos-Fet power switches used in switching power supplies sometimes fail due to a malfunction of any other elements that can disable it in the key mode, or create an excess of the maximum permissible key parameters. These can be elements supplying a PWM regulator, frequency setting or damper circuits, or elements of negative feedback in the stabilization circuit. PWM controllers FA5696, LNK6777, MP4653, in the absence of visible damage or outright short circuits between the terminals, are checked by replacing them with new ones, or knowingly working.
- There is no image, there is sound, it reacts to the remote control. Or the image may appear for a second when turned on and disappear immediately.
Most likely in these cases is a malfunction of the LED backlight. Often the reason is a malfunction of the LEDs (open circuit, short circuit ...), or the connectors of the strips (strings), less often the LED driver turns out to be faulty.
To check the LED strips for breakage without disassembling the panel, for example, a current source will help. It is impossible to open series-connected PN junctions with a simple multimeter; a voltage of the order of several tens of volts is required.
- TV does not turn on, does not respond to the remote control. The indicator blinks or signals the standby mode.
Repair or diagnostics of the MSD3463-T8D1 motherboard should begin with checking the stabilizers and power converters required to power the microcircuits and matrix. If necessary, you should update or replace the software (software). In some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - CPU: MSD3463SGA, SPI Flash: MX25L6406E, AUDIO: TPA3110LD2 with new or known good ones. In cases where BGA technologies are used, defects are usually localized by heating.
If there is no tuning for terrestrial or cable TV channels, you should make sure that the software is correct, as well as that the supply voltages on the terminals of the ST43WS-2A-E (Si2151) tuner match. It is also necessary to check with an oscilloscope the presence of pulses of data exchange between the tuner and the processor via the I2C bus.

We remind users again! Attempts to self-repair the SUPRA STV-LC50LT0010F TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!


SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    SUPRA STV-LC50LT0010F V1S10 MAINBOARD: MSD3463-T8D1

FIRMWARE FOR SPI FLASH  ----------->   SUPRA STV-LC50LT0010F V1S10, Main: MSD3463-T8D1, Panel: K490WDC1


 The appearance of the MainBoard MSD3463-T8D1 is shown in the figure below:
MSD3463-T8D1
Main features of SUPRA STV-LC50LT0010F device:
Installed matrix (LED panel) K490WDC1.
To power the backlight LEDs, a converter combined with the MSD3463-T8D1 main board is used, controlled by the MP4653 PWM controller. Keys of type 7N65, AOD4504 are used as power elements of the LED driver.
The power module is combined with the MainBoard and is made according to the AC / DC flyback converter circuit using the FA5696, LNK6777, MP4653 microcircuits and power switches of the FMV13N60S1, 7N65 type.
MainBoard - the main board (motherboard) is an MSD3463-T8D1 module, using CPU chips: MSD3463SGA, SPI Flash: MX25L6406E, AUDIO: TPA3110LD2 and others.
Tuner ST43WS-2A-E (Si2151) provides reception of television programs and tuning to channels ................
SUPRA LED TV STV-LC50LT0010F with LCD K490WDC1, diagonal size 49 "(124 cm) 16: 9. The required screen brightness of 350 cd / m² is provided by LED backlighting. Dynamic contrast ratio of 120,000: 1 is achieved by special LED control depending on the illumination of the areas in the scene. The display technology of the model uses LED backlighting. The capabilities of the TV provide viewing of broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphic decomposition according to the standard 1080p (Full HD). Supported media file formats: MP3 , WMA, MPEG4, Xvid, DivX, MKV, JPEG.
Speaker power 16 W (2x8 W) is provided by two speakers. Uses NICAM stereo signal processing system and Sound Surround function.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, VGA, HDMI x3, USB x2. A headphone output is provided. The digital tuner is capable of receiving TV channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
The power consumed by the TV in operating mode from the network is 110 watts.
Overall dimensions: 1103x693x252 mm.
Attention! The panel K490WDC1 of the SUPRA STV-LC50LT0010F LED TV is an expensive and unreliable element.
Do not allow any impacts on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.