Tuesday, 28 July 2020

REPAIR / SERVICING TV SUPRA STV-LC40T800FL

Technical description and composition of the SUPRA STV-LC40T800FL TV, panel type and modules used. The composition of the modules.
SUPRA LED
Model: STV-LC40T800FL
Chassis / Version: V1P01
Panel: C400F14-E8-C
LED driver (backlight): integrated into MainBoard
PWM LED driver: MP4012
MOSFET LED driver: MMD14N25
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: JUC7.820.00123957 HLT57EJ
IC MainBoard: CPU: 9206B, SPI Flash: GD25Q64, TPA3110D
Tuner: CH DM121 C816RH
STV-LC40T800FL Specifications
SUPRA STV-LC40T800FL
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- SUPRA STV-LC40T800FL 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 remote control and control buttons.
In such cases, the common power supply is often faulty - the AC / DC converter of the mains voltage, which is combined with the elements of the JUC7.820.00123957 main board. It is necessary to measure its secondary output voltages, and if they are absent, check the power switches and rectifier diodes in the converters for a short circuit.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in an emergency mode of short circuit without output voltages, and with a short circuit in the elements of the primary circuit, the mains fuse most often breaks off immediately and less often the current sensor in the source of the key.
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) PWM SOT23-6, if they have no visible damage to the case and an open short circuit between the pins, are usually checked by replacing.
- There is no image, there is sound, it reacts to the remote control. Or the image may appear for a second when turned on and disappear immediately.
In such cases, the most likely malfunction of the LED panel backlighting elements. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
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 TV does not turn on, the indicator signals standby or operating mode, or blinks.
Repair or diagnostics of the JUC7.820.00123957 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 an MB board, you need to check its components CPU: 9206B, SPI Flash: GD25Q64, TPA3110D. 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.
In cases where 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 CH DM121 C816RH tuner terminals 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.

Attention to TV owners! Attempts to repair SUPRA STV-LC40T800FL yourself are not recommended by the manufacturer and can lead to serious negative consequences!


DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   SUPRA STV-LC40T800FL V1P01, Main: JUC7.820.00123957 HLT57EJ, Panel: C400F14-E8-C

 The appearance of the MainBoard JUC7.820.00123957 is shown in the figure below:
JUC7.820.00123957
JUC7.820.00123957 can be used in TVs:
DEXP F40B7200C (Panel C400F14-E6-C (G5)), SUPRA STV-LC40T440FL (Panel C400F15-E2-S (G01)), SUPRA STV-LC40T800FL (Panel C400F14-E8-C).
Main features of SUPRA STV-LC40T800FL device:
Installed matrix (LED panel) C400F14-E8-C.
To power the backlight LEDs, a converter combined with the JUC7.820.00123957 main board is used, controlled by the MP4012 PWM controller. The keys of the MMD14N25 type 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 voltage converter using PWM SOT23-6 microcircuits.
MainBoard - the main board (motherboard) is a JUC7.820.00123957 module, using CPU chips: 9206B, SPI Flash: GD25Q64, TPA3110D and others.
Tuner CH DM121 C816RH provides reception of television programs and tuning to channels.
SUPRA LED TV STV-LC40T800FL with LCD C400F14-E8-C, diagonal 40 "(102 cm) in 16: 9 format. The required screen brightness of 280 cd / m² is provided by LED backlighting. Dynamic contrast ratio of 100,000: 1 is achieved special control of the LEDs depending on the illumination of the areas in the scene.This model uses an LED-panel with an edge arrangement of backlighting LEDs - Edge LED.Possibilities of the TV provide viewing of broadcasts and films in high quality HD at a resolution of 1920x1080 pixels in graphic resolution according to 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 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, 1280x1024, 1360x768, 1920x1080. The digital tuner is capable of receiving TV channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Overall dimensions: 980x623x160 mm.
Attention! SUPRA STV-LC40T800FL LED TV panel C400F14-E8-C 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.