Technical description and composition of the SUPRA STV-LC42740FL TV, panel type and modules used. The composition of the modules.SUPRA LED
Model: STV-LC42740FL
Chassis / Version: V1L11
Panel: V420HJ1-P01
LED driver (backlight): integrated into MainBoard
Power Supply (PSU): integrated into MainBoard
PWM Power: FAN6755W
MainBoard: KL42GT611-CMI-23YTK
IC MainBoard: MT8227, MX25L3206E, STA333W
Tuner: TDA18273
Control: IR: 35016976
STV-LC42740FL Specifications
SUPRA STV-LC42740FL
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- SUPRA STV-LC42740FL TV does not turn on and does not show any signs of operation. There is no reaction to either the remote control or the front panel control buttons.
A malfunction in such cases should be looked for in the elements of the power source - the mains voltage converter (AC / DC), which is located on the main board KL42GT611-CMI-23YTK. It is necessary to measure its secondary output voltages, and if they are absent, check the serviceability of the power switches of the converters and rectifier diodes for a short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in short-circuit mode, and in case of short-circuit in the elements of the primary circuit, the mains fuse usually breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can disable it in the key mode, or provoke an excess of the maximum current or voltage values. These can be supply, damper circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power switch can also be the PWM (PWM) FAN6755W. It is checked only by replacing it with a known good one.
- There is no picture, but there is sound, it reacts to the remote control. Or the image appears when turned on and disappears immediately
A malfunction is usually in these cases most likely in the backlight units of the display matrix. 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.
To check the health of the LED circuit, it is better to use a current source with a maximum voltage of 200V. We do not recommend using any voltage sources for this purpose. You can check each LED separately with a simple Chinese multimeter (powered by 9 volts) in the P-N transition test mode. If you connect the red probe of the multimeter to the anode of the LED, and the black one to its cathode, then the 3-volt LED will light up slightly, and in the opposite direction you can detect the transition of the emergency zener diode. The serviceability of the PN junction of the Zener diode indirectly indicates the serviceability of the LED-a
- The TV does not turn on, the indicator signals standby or operating mode, or blinks.
Repair or diagnostics of the KL42GT611-CMI-23YTK 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). If it is not possible to replace the MB (SSB) board, it is necessary to check the serviceability of its elements - MT8227, MX25L3206E, STA333W. Defective components must be replaced.
If you suspect a malfunction of the TDA18273 tuner, first of all, you need to make sure that the software is correct, as well as the presence of the required supply voltage levels and pulses of data exchange with the processor via the I2C bus on the corresponding tuner pins.
Owners of the STV-LC42740FL TV are advised to contact only qualified specialists with the necessary experience for repair! Attempts to repair yourself without the appropriate knowledge and skills can lead to irreversible negative consequences!
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> SUPRA STV-LC22740WL, STV-LC26740WL, STV-LC42740FL processor MT8227
The appearance of the MainBoard KL42GT611-CMI-23YTK is shown in the figure below:KL42GT611-CMI-23YTK
Main features of SUPRA STV-LC42740FL device:
Installed matrix (LED panel) V420HJ1-P01.
A converter combined with the KL42GT611-CMI-23YTK main board is used to power the backlight LEDs.
The power module is combined with the MainBoard and is made according to the AC / DC flyback voltage converter using FAN6755W microcircuits.
MainBoard - the main board (motherboard) is a KL42GT611-CMI-23YTK module, using MT8227, MX25L3206E, STA333W and others.
The TDA18273 tuner provides reception of television programs and tuning to channels.
Information from an alternative source:
SUPRA STV-LC42740FL
Panel type (matrix): CA1T34TD ?,
Motherboard: CMI-V420HJ1-P01 Version V1M01, PCKDF6755 (FAN6755 -?), STV333W, OZ9902AGN, 25Q328VSIG
Additional technical information about the panel:
Brand: CHIMEI INNOLUX
Model: V420HJ1-P01
Type: a-Si TFT-LCD, CELL
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: MVA, Normally Black, Transmissive
Active Area: 930.24x523.26 mm
Surface: Antiglare (Haze 3.5%), Hard coating (3H)
Glass Depth: 0.70 + 0.70 mm
Transmissivity: 5.7% (with Polarizer)
Contrast Ratio: 4000: 1
Display Colors: 16.7M (8-bit)
Response Time: 8 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V
SUPRA LED TV STV-LC42740FL with LCD V420HJ1-P01, 42 "(107 cm) 16: 9 diagonal. The required screen brightness of 380 cd / m² is provided by LED backlighting. Dynamic contrast ratio of 100,000: 1 is achieved by special control operation of LEDs depending on the illumination of areas in the scene.This model uses an LED-panel with an edge arrangement of backlighting LEDs - Edge LED.The TV capabilities provide viewing of broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphics resolution in 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 the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, MKV, JPEG.
Speaker power of 10 W (2x5 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, component, VGA, HDMI x3, USB. A headphone output is provided. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector on the TV case is used, this interface supports resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080.
The power consumed by the TV in operating mode from the network is 120 watts.
Overall dimensions: 1170x660x165 mm.
TV weight: 15 kg.
Attention! SUPRA STV-LC42740FL LED TV panel V420HJ1-P01 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.
