Thursday, 30 July 2020

REPAIRING / SERVICING TV SUPRA STV-LC32T880WL

 Technical description and composition of the SUPRA STV-LC32T880WL TV, panel type and modules used. The composition of the modules.
SUPRA LED
Model: STV-LC32T880WL
Chassis / Version: V1P10
Panel: C320X14-E13-L
LED backlight: LB-C320X14-E12-H-G1-SE3
T-CON: MT3151A05-5-XC-5
LED driver (backlight): integrated into MainBoard
PWM LED driver: MP4012
MOSFET LED driver: TO-252
Power Supply (PSU): integrated into MainBoard
PWM Power: NCP1251A
MOSFET Power: 70R600P
MainBoard: JUC7.820.00130484
IC MainBoard: CPU: MSMHFK 9206B, Flash: 25Q64
Tuner: CH DM121 C816RH
STV-LC32T880WL Specifications
SUPRA STV-LC32T880WL
General recommendations for TV LCD LED repair
Possible manifestations of defects
- SUPRA STV-LC32T880WL TV does not turn on. There are no signs of operability. The indicators on the front panel do not light up or blink, the TV does not respond to the control buttons.
First of all, in such cases, you should make sure that the common switching power supply (SMPS) - the AC / DC voltage converter of the mains voltage - is working. All source elements in this TV model are located on the MainBoard JUC7.820.00130484. Then we recommend measuring its output voltages and, if they are absent, you should check the serviceability of the power switches (70R600P) and the rectifier diodes of the converters for a possible short circuit.
In case of breakdowns in the secondary circuits, the converter, as a rule, can operate in an emergency in the short-circuit mode, and in case of a short circuit in the power elements of the primary circuit, the mains fuse usually breaks off.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements, which can disable it in key mode, or provoke an excess of the maximum current or voltage values. These can be circuits supplying the PWM controller, damper or frequency setting circuits, or OOS (negative feedback) elements in the stabilization circuit. PWM controllers (PWM) NCP1251A, in the absence of external damage and a short circuit between the terminals, are checked by replacing them with known good ones.
- There is no image, there is sound, it reacts to the remote control. Or, immediately after switching on for a second, the image may appear and immediately disappear.
Often in such cases there is no backlighting of the LED panel. The reason may be in the breakage of the LEDs, in the stabilization of their power supply, or in the violation of the contact connections of the strings connectors,
To identify an open circuit in the LED lines without disassembling the panel, a current source is required. It is impossible to open the junctions connected in series with a simple multimeter; a voltage of several tens of volts is required.
- The indicator blinks or is on constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the JUC7.820.00130484 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). Repair of the board and replacement of CPU: MSMHFK 9206B, Flash: 25Q64 microcircuits are made if the necessary equipment and the corresponding element base are available. Malfunctions associated with the use of BGA soldering technologies can be localized by warming up.
If you suspect a malfunction of the CH DM121 C816RH tuner, first of all, you need to make sure that the software is correct, as well as the presence of the necessary levels of supply voltages and pulses of data exchange with the processor via the I2C bus on the corresponding terminals of the tuner.
We remind users again! Attempts to repair the SUPRA STV-LC32T880WL TV on your own without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!


DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   SUPRA STV-LC32T880WL V1P10, Main: JUC7.820.00130484, Panel: C320X14-E13-L


 The appearance of the MainBoard JUC7.820.00130484 is shown in the figure below:
JUC7.820.00130484
Main features of SUPRA STV-LC32T880WL device:
Installed matrix (LED panel) C320X14-E13-L.
Matrix control uses Timing Controller (T-CON) MT3151A05-5-XC-5.
To power the backlight LEDs, a converter combined with the JUC7.820.00130484 main board is used, controlled by the MP4012 PWM controller. TO-252 switches 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 NCP1251A microcircuits and 70R600P power switches.
MainBoard - the main board (motherboard) is a JUC7.820.00130484 module, using CPU chips: MSMHFK 9206B, Flash: 25Q64 and others.
Tuner CH DM121 C816RH provides reception of television programs and tuning to channels.
SUPRA LED TV STV-LC32T880WL with LCD C320X14-E13-L, 32 "(81 cm) 16: 9. The required screen brightness of 300 cd / m² is provided by LED backlighting. Dynamic contrast ratio of 100000: 1 is achieved special control of the LEDs depending on the illumination of areas in the scene. The display technology of the model uses LED LED backlight. It is possible to view broadcasts and films and images in high quality HD at a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). Input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC Graphic processing and digital signal shaping occurs in 480i, 480p, 576i, 576p, 720p, 1080i, 1080p standards Supported media 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, audio x2, component, 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: 640x480, 800x600, 1024x768, 1360x768. The digital tuner is capable of receiving TV channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Overall dimensions: 820x530x160 mm.
Attention! SUPRA STV-LC32T880WL LED TV panel C320X14-E13-L 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 non-repairable.