Monday 27 July 2020

REPAIR / SERVICING TV SUPRA STV-LC48T400FL

Technical description and composition of the SUPRA STV-LC48T400FL TV, panel type and modules used. The composition of the modules.
SUPRA LED
Model: STV-LC48T400FL
Chassis / Version: HK-T.SP9202V51
Panel: MT4761B01-1 XL2
LED driver (backlight): integrated into PSU
Power Supply (PSU): SHG4202A-191S
MainBoard: HK-T.SP9202V51
IC MainBoard: Flash GD25Q32
STV-LC48T400FL Specifications
SUPRA STV-LC48T400FL
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- SUPRA STV-LC48T400FL does not turn on, LEDs on the front panel do not light or flash. The TV does not respond to control buttons and the remote control.
In such cases, the SHG4202A-191S power supply usually fails. Its output voltages should be measured and, in their absence, the serviceability of the power switches and rectifier diodes in the converters should be checked for possible breakdown.
In case of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and in case of a short circuit in the power elements of the primary circuit, the mains fuse and / or the current sensor in the source of the key usually breaks 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, in the absence of visible damage or outright short circuits between the terminals, are checked by replacing them with new ones, or knowingly working properly.
- There is no picture, but there is sound, it reacts to the remote control. Or the image appears when turned on and disappears immediately
As a rule, in this case, the backlight of the LED panel is faulty. The reason can sometimes be in the power supply of the LEDs, but more often in their malfunction (breakdown or breakage), sometimes in the violation of the contact connections of the LED strips.
It should be remembered that it is not possible to determine an open circuit in the LED lines without disassembling the panels using a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required. Then you need to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow you to open the LED in the forward direction or dual LEds are used, then the PN transition of the emergency zener diode can indirectly serve as an indicator of serviceability. In the event of a malfunction of the LED-a, the PN-transition of the zener diode will either be cut off or broken through in the SC.
- The indicator on the front panel blinks, the TV does not turn on in operating mode, does not respond to the remote control.
Repair or diagnostics of the HK-T.SP9202V51 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). Sometimes it is necessary to check or replace (if necessary) elements of the MainBoard - Flash GD25Q32. In cases where a BGA processor is used, its malfunction is usually detected by the local warm-up method.
Users and owners of TVs should remember that attempts to self-repair a SUPRA STV-LC48T400FL TV without the appropriate qualifications and the necessary experience can lead to serious negative consequences!


FIRMWARE FOR SPI FLASH  ----------->   SUPRA STV-LC48T400FL, Main: HK-T.SP9202V51, Panel: MT4761B01-1-XL2

 The appearance of the MainBoard HK-T.SP9202V51 is shown in the figure below:
HK-T.SP9202V51
HK-T.SP9202V51 can be used in TVs:
SUPRA STV-LC48T400FL (Panel MT4761B01-1 XL2), SUPRA STV-LC50T400FL (Panel T500HVN07.1 XL).
External view of the power supply
Main features of SUPRA STV-LC48T400FL device:
Installed matrix (LED panel) MT4761B01-1 XL2.
A converter combined with a power supply is used to power the backlight LEDs.
The formation of the necessary supply voltages for all nodes of the SUPRA STV-LC48T400FL TV is carried out by the SHG4202A-191S power module, or its analogs.
MainBoard - the main board (motherboard) is a HK-T.SP9202V51 module, using Flash GD25Q32 chips and others.
Additional technical information about the panel:
Brand: CSOT
Model: MT4761B01-1
Type: a-Si TFT-LCD, Panel
Diagonal size: 48 inch
Resolution: 1920x1080, FHD
Display Mode: HVA, Normally Black, Transmissive
Active Area: 1054.08x592.92 mm
Surface: Antiglare (Haze 2%), Hard coating (3H)
Brightness: 400 cd / m²
Contrast Ratio: 4000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 6.5 (G to G)
Frequency: 120Hz (60Hz Input)
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V
SUPRA LED TV STV-LC48T400FL with LCD MT4761B01-1, diagonal size 48 "(122 cm) 16: 9. The required brightness of the screen 350 cd / m² is provided by LED backlight. Dynamic contrast ratio of 150,000: 1 is achieved by special control operation of LEDs depending on the illumination of areas in the scene.This model uses an LED-panel with an edge arrangement of backlighting LEDs - Edge LED.The TV capabilities provide viewing of broadcasts and films in high quality HD at a resolution of 1920x1080 pixels in graphic resolution in the standard 1080p (Full HD ) .Input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal shaping occurs in standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, 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, audio x2, component, SCART, VGA, HDMI x3, USB. 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: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080. The digital tuner is capable of receiving TV channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Dimensions: With stand 1100x705x260 mm, Without stand 1100x647x98 mm.
TV weight: 15 kg.
Attention! The panel MT4761B01-1 XL2 of the SUPRA STV-LC48T400FL 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.