Technical description and composition of the SUPRA STV-LC50T950UL TV, panel type and modules used. The composition of the modules.SUPRA LED
Model: STV-LC50T950UL
Chassis / Version: V1N12
Panel: ST4851D01-2
LED driver (backlight): integrated into PSU
PWM LED driver: BD9211F
Power Supply (PSU): AY156D-4SF 3BS0054914
PWM Power: LD7537, L6562A
MOSFET Power: MDF4N60BTH, MDF9N50BTH
MainBoard: CV309H-F
IC MainBoard: SPI FLASH: 25Q32
Tuner: NoName
STV-LC50T950UL Specifications
SUPRA STV-LC50T950UL
General recommendations for TV LCD LED repair
Possible manifestations of defects
- SUPRA STV-LC50T950UL TV does not turn on at all. No response to the remote control and front panel control buttons. Indicator lamps do not light up or flash.
Most often, with similar manifestations, the main power module AY156D-4SF turns out to be faulty. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, the serviceability of the power switches (MDF4N60BTH, MDF9N50BTH) and rectifier diodes should be checked for a possible breakdown (short circuit).
In case of any breakdowns in the secondary circuits, the converter can operate in an emergency mode of a short circuit, and with a short circuit in the power elements of the primary circuit, the mains fuse or current sensor in the source of the key is often cut off.
Breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM controllers (PWM) LD7537, L6562A, if they do not have visible damage to the case and an outright short circuit between the terminals, are usually checked by replacing.
- No picture, sound, all other TV functions work. When turned on, the image may sometimes appear for a second.
Usually, in such cases, a malfunction is detected in the nodes of the LED panel 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.
It is impossible to detect a break in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and a voltage of several tens of volts is required to open their junctions. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Usually, Chinese multimeters lightly light up one 3-volt LED if you connect the probes to it in the forward direction (red probe to the anode, black to the cathode). For dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of LED health. In the event of a malfunction of the LED, its zener diode will either be cut off or broken into the K / Z.
- The TV does not go into operation, does not respond to the remote control. The indicator on the front panel is on or blinking.
Repair or diagnostics of the CV309H-F motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). Often the MB (SSB) board needs to be replaced in case of complex malfunctions that are difficult to detect. When attempting to repair, you should check its elements - SPI FLASH: 25Q32 and replace the failed chips with new ones. Some malfunctions may be associated with the use of BGA soldering technologies in modern Main Board. Typically, such defects are detected by local heating of the chip.
If there is no tuning to channels of terrestrial 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 NoName tuner outputs. 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.
Remember! Attempts to self-repair the SUPRA STV-LC50T950UL TV, in the absence of the necessary qualifications and experience, are strictly not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!
FIRMWARE FOR SPI FLASH -----------> U19 25Q32 SUPRA STV-LC50T950UL V1N12, Main: CV309H-F, Panel: ST4851D01-2
The appearance of the MainBoard CV309H-F is shown in the figure below:CV309H-F
External view of the power supply
Main features of SUPRA STV-LC50T950UL device:
Installed matrix (LED panel) ST4851D01-2.
To power the backlight LEDs, a converter combined with a power supply is used, controlled by a BD9211F PWM controller.
The formation of the necessary supply voltages for all nodes of the SUPRA STV-LC50T950UL TV is carried out by the AY156D-4SF power module, or its analogs using LD7537, L6562A microcircuits and power switches such as MDF4N60BTH, MDF9N50BTH.
MainBoard - the main board (motherboard) is a CV309H-F module, using SPI FLASH chips: 25Q32 and others.
Tuner NoName provides reception of television programs and tuning to channels.
SUPRA LED TV STV-LC50T950UL with LCD ST4851D01-2, diagonal size 49 "(124 cm) 16: 9. The required screen brightness of 400 cd / m² is provided by LED backlighting. Dynamic contrast ratio of 150,000: 1 is achieved by special control operation of LEDs depending on the illumination of areas in the scene.The production technology of the model's display uses LED LED backlighting.It is possible to view films and images in the highest UHD quality at a resolution of 3840x2160 pixels in the 4K UHD standard.Input high-frequency or video signal is decoded in analog systems PAL, SECAM , NTSC Graphic processing and digital signal shaping occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p Supported multimedia file formats: MP3, WMA, MPEG4, MKV, JPEG.
Speaker power of 16 W (2x8 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, component, SCART, VGA, HDMI x3, USB. A headphone output is provided. To connect a computer or laptop to this TV model, use the VGA (D-Sub 15) connector on the TV case, this interface supports resolutions: 1920x1080, 3840x2160. The digital tuner is capable of receiving TV channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Overall dimensions: 1180x725x170 mm.
Attention! The ST4851D01-2 panel of the SUPRA STV-LC50T950UL 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.