Tuesday, 14 July 2020

REPAIR / SERVICING TV SUPRA STV-LC22T440FL

 Technical description and composition of the TV SUPRA STV-LC22T440FL, type of panel and applicable modules. The composition of the modules.
SUPRA LED
Model: STV-LC22T440FL
Chassis / Version: V1P12
Panel: C215F14-E5-P
LED driver (backlight): integrated into PSU
PWM LED driver: OB3350CP
MOSFET LED driver: ME15N10
Power Supply (PSU): Adapter 12V
MainBoard: JUC7.820.00128709
IC MainBoard: SPI Flash: 25Q64, Audio: YD1517P
Tuner: CH DMI21-8I6RH
Control: Service mode: SOURCE 3138
Technical Specifications STV-LC22T440FL
SUPRA STV-LC22T440FL
General repair guidelines for TV LCD LED
Possible malfunctions
- The SUPRA STV-LC22T440FL TV does not turn on and does not show any signs of turning on, does not respond to the control buttons or to the remote control.
In some of these cases, the main switching power supply, the Adapter module, is faulty.
The owner of the TV can purchase an external power supply unit such as Adapter and repairing it is not always advisable. In any case, the simplest typical defects characteristic of most IIP schemes can be easily detected and eliminated after opening. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches and rectifier diodes for a possible partial or complete breakdown.
In case of breakdowns of the diodes in the secondary circuits, the converter can operate in emergency short circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor at the source of the key usually breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM), in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it on and immediately disappears
As a rule, in such cases there is no display backlight. The reason can 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 line of LEDs without disassembling the panel with a simple multimeter. LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect the probes in the forward direction to it (red probe to the anode, black to the cathode). In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of health. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the JUC7.820.00128709 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). Often, the MB (SSB) card must be replaced in case of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - SPI Flash: 25Q64, Audio: YD1517P and replace failed chips with new ones. Some malfunctions can be associated with the use of BGA soldering technologies in modern Main Board technologies. Typically, such defects are detected by local heating of the chip.
Before replacing the CH DMI21-8I6RH tuner, if there is no tuning for the channels, you must first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus
Once again, remind users! Attempts to self-repair a TV SUPRA STV-LC22T440FL without the appropriate qualifications and necessary experience can lead to its complete non-repairability!


FIRMWARE FOR SPI FLASH  ----------->   SUPRA STV-LC22T440FL V1P10, Main: JUC7.820.00128709, Panel: C215F14-E5-P


 The appearance of the MainBoard JUC7.820.00128709 is shown in the figure below:
JUC7.820.00128709
JUC7.820.00128709 can be used in TVs:
BBK 24LEM-1015 / T2C (Panel C240X14-E3-C (G6)), BBK 19LEM-1015 / T2C (Panel C185X14-E5-P), SUPRA STV-LC22T440FL (Panel C215F14-E5-P).
Main features of the SUPRA STV-LC22T440FL device:
Installed matrix (LED-panel) C215F14-E5-P.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the OB3350CP PWM controller. As the power elements of the LED driver, keys of the type ME15N10 are used.
To power all the internal nodes of the SUPRA STV-LC22T440FL TV, an external adapter 12V type source is used.
MainBoard - the main board (motherboard) is a JUC7.820.00128709 module, using SPI Flash chips: 25Q64, Audio: YD1517P and others.
The CH DMI21-8I6RH tuner provides TV reception and channel tuning.
LED TV SUPRA STV-LC22T440FL with LCD C215F14-E5-P, diagonal size 22 "(56 cm) 16: 9 format. The required brightness of the screen is 230 cd / m² LED backlight LED. Dynamic contrast ratio of 60,000: 1 is achieved special control of the operation of the LEDs depending on the illuminance of the plots in the plot.In this model, an LED panel with an end arrangement of the backlight LEDs - Edge LED is used. Full HD). The input high-frequency or video signal is decoded in analogue 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 4 W (2x2 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, audio x2, 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, 1280x1024, 1360x768, 1920x1080. A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Overall dimensions: 570x385x110 mm.
Attention! The C215F14-E5-P panel of a SUPRA STV-LC22T440FL 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.