Monday 3 August 2020

REPAIRING / SERVICING TV SUPRA STV-LC32LT0010W

Technical description and composition of the SUPRA STV-LC32LT0010W TV, panel type and modules used. The composition of the modules.
SUPRA LED
Model: STV-LC32LT0010W
Chassis / Version: CV512H-U42
Panel: KM0320LDRH0037
LED backlight: CC02320D570V12
T-CON: CV315PW07S; HX8861-J, 4G16, 503Y
LED driver (backlight): integrated into MainBoard
PWM LED driver: PWM 8pin
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: CV512H-U42
IC MainBoard: W25Q64
Tuner: CDT-9NT372
STV-LC32LT0010W Specifications
SUPRA STV-LC32LT0010W
General recommendations for TV LCD LED repair
Possible manifestations of defects
- SUPRA STV-LC32LT0010W TV does not turn on and does not show any signs of turning on, does not respond to control buttons and to the remote control.
In such cases, the main power source, the AC / DC converter of the mains voltage, which is combined with the MainBoard CV512H-U42, may be faulty. It is necessary to measure the output voltages in its secondary circuits, and in the event of their complete absence, the serviceability of the power switches and rectifier diodes should be checked for a possible breakdown (short circuit).
In case of breakdowns in the secondary circuits of the converter, it can usually work in an emergency mode in a short circuit mode, 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 most often 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 PWM SOT23-6, 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 and reaction to commands from the remote control. Or the image appears immediately after switching on and disappears.
Usually, in such cases, a malfunction is detected in the nodes of the backlight of the LED panel. The reason may be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
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 turn on, the indicator signals standby or operating mode, or blinks.
Repair or diagnostics of the CV512H-U42 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). When repairing the MB board, you need to check its W24Q64 components. Defective elements must be replaced. If chips with BGA soldering technology are used, the problem in its implementation is detected by local heating of the chip.
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 outputs of the CDT-9NT372 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.
Once again, we remind TV users: do not attempt to repair yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repair to professionals with sufficient experience in the field of electronic repair.


https://4.bp.blogspot.com/-6lb8bSVHVq0/XygbVqeDaMI/AAAAAAABC8M/fh5yUaMujfEHBriIk3Fml2smeilp1q9nQCK4BGAYYCw/s1600/CV512H-U42_DCE.jpgThe appearance of the MainBoard CV512H-U42 is shown in the figure below:
CV512H-U42
CV512H-U42 can be used in TVs:
DEXP H39D7000Q (Panel LC390TA2A), SUPRA STV-LC32LT0010W (Panel KM0320LDRH0037).
Main features of SUPRA STV-LC32LT0010W device:
Installed matrix (LED-panel) KM0320LDRH0037.
Matrix control uses Timing Controller (T-CON) CV315PW07S ;.
To power the backlight LEDs, a converter combined with the CV512H-U42 main board is used, controlled by a PWM 8pin PWM controller.
The power module is combined with the MainBoard and is made according to the AC / DC flyback voltage converter using PWM SOT23-6 microcircuits.
MainBoard - the main board (motherboard) is a CV512H-U42 module, using W25Q64 and others.
The CDT-9NT372 tuner provides reception of television programs and tuning to channels.
SUPRA LED TV STV-LC32LT0010W with LCD display KM0320LDRH0037, 32 "(81 cm) 16: 9 diagonal. The required brightness of the screen of 280 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. 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). Supported media file formats: MP3, WMA, MPEG4, Xvid, DivX, MKV, JPEG.
Speaker power 20 W (2x10 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 television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Overall dimensions: 805x507x150 mm.
Attention! The panel KM0320LDRH0037 of the SUPRA STV-LC32LT0010W 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 non-repairable.