Friday 17 July 2020

REPAIR / SERVICING TV SUPRA STV-LC19T550WL

Technical description and composition of the TV SUPRA STV-LC19T550WL, type of panel and applicable modules. The composition of the modules.
SUPRA LED
Model: STV-LC19T550WL
Chassis / Version: V1P12
Panel: HM185WX3-401
LED driver (backlight): integrated into MainBoard
PWM LED driver: SN51DP
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: TP.MS3463S.PA63
IC MainBoard: SPI FLASH: GD25Q64
Tuner: XF-3SDT-H
Technical Specifications STV-LC19T550WL
SUPRA STV-LC19T550WL
General repair guidelines for TV LCD LED
Possible manifestations of defects
- SUPRA STV-LC19T550WL does not turn on, the indicators on the front panel do not light or flash. The TV does not respond to the control buttons and the remote control.
In such cases, the AC / DC converter of the mains voltage, which is combined with the main board TP.MS3463S.PA63, is often faulty. It is necessary to measure its output voltages and, if they are absent, to check the short circuit probability in the converters power switches and rectifier diodes.
For any breakdown of semiconductors in the secondary circuits, the converter can usually work normally in emergency short circuit mode. There are no output voltages. And during short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and less often the current sensor at the source of the key.
Mos-Fet power switches, used in switching power supplies, sometimes fail due to a malfunction of any other elements that can put it out of operation in key mode, or create an excess of the maximum permissible parameters of the switch. These can be elements supplying the PWM controller, frequency-setting or damping circuits, or negative feedback elements in the stabilization circuit. PWM SOT23-6 PWM controllers, in the absence of visible damage or obvious short-circuit between the terminals, are checked by replacing with new ones, or obviously working.
- 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.
Failure in most such cases is detected in the nodes and backlight elements of the LED panel. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to check the line of series-connected LEDs without a special current source, and for this purpose it is not safe to use any voltage sources above 12V for them. Then it remains only to open the panel and check each LED separately. Usually, Chinese 9V powered multimeters light up a single 3-volt LED, if you connect the probes in the forward direction, the red probe to the anode, and the black to the cathode. In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as a health indicator. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- The indicator blinks or lights up constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the TP.MS3463S.PA63 motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). Board repair and replacement of chips SPI FLASH: GD25Q64 are made in the presence of the necessary equipment, and the corresponding element base. Faults associated with the use of BGA processor soldering technology can be localized by the heating method.
If the TV works normally from external devices, but does not tune into television channels, the tuner XF-3SDT-H may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Attention to users! Self-repair of a TV SUPRA STV-LC19T550WL without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!


FIRMWARE FOR SPI FLASH  ----------->   SUPRA STV-LC19T550WL V1P12, Main: TP.MS3463S.PA63, Panel: HM185WX3-401

 The appearance of MainBoard TP.MS3463S.PA63 is shown in the figure below:
TP.MS3463S.PA63
TP.MS3463S.PA63 can be used in TVs:
ERISSON 22LES76T2 (Panel ST2151B01-1-XC-3), SUPRA STV-LC19T550WL (Panel HM185WX3-401), SUPRA STV-LC22T550FL (Panel T215HVN01).
Main features of the SUPRA STV-LC19T550WL device:
Installed matrix (LED-panel) HM185WX3-401.
To power the backlight LEDs, a converter is used, combined with the TP.MS3463S.PA63 main board, controlled by the SN51DP PWM controller.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit using PWM SOT23-6 microcircuits.
MainBoard - the main board (motherboard) is a TP.MS3463S.PA63 module, using SPI FLASH chips: GD25Q64 and others.
The XF-3SDT-H tuner allows you to receive television programs and tune to channels.
Additional technical information about the panel:
Brand: BOE
Model: HM185WX3-401
Type: a-Si TFT-LCD, CELL
Diagonal size: 18.5 inch
Resolution: 1366x768, WXGA
Display Mode: TN, Normally White, Transmissive
Active Area: 409.8x230.4 mm
Surface: Antiglare (Haze 25%), Hard coating (3H), Antireflection
Glass Depth: 0.50 + 0.50 mm
Transmissivity: 5.4% (with Polarizer)
Contrast Ratio: 1000: 1
Display Colors: 16.7M (6-bit + Hi-FRC)
Response Time: 1.5 / 3.5 (Tr / Td)
Frequency: 60Hz
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V
LED TV SUPRA STV-LC19T550WL with LCD HM185WX3-401, diagonal size 18.5 "(47 cm) 16: 9 format. The required brightness of the screen 200 cd / m² is provided by LED backlight LED. Dynamic contrast ratio of 60000: 1 is achieved by special control LEDs work depending on the illuminated areas in the plot.In this model, an LED panel with the end position of the backlight LEDs, Edge LED, is used. The input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, WMA, MPEG4, MKV , 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, component, VGA, HDMI, USB. 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, 1360x768. A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Overall dimensions: 500x340x120 mm.
Attention! The HM185WX3-401 panel of a SUPRA STV-LC19T550WL LED TV is an expensive and unreliable element.
Avoid any impact on the glass and pressure on the surface of the screen to avoid damage to the LED panel!
It is also unsafe to get liquid on the screen. Sometimes one drop is enough if it flows down the glass onto the cables so that the TV becomes unrepairable.