Technical description and composition of the SUPRA STV-LC42790FL TV, panel type and modules used. The composition of the modules.SUPRA LED
Model: STV-LC42790FL
Chassis / Version: T.MS18VG.72B 12023
Panel: HK420LEDM-AH17H
T-CON: T420HW08 V0 XL
Power Supply (PSU): LK-PL420406
MainBoard: T.MS18VG.72B 12023
IC MainBoard: Flash 25Q32
STV-LC42790FL Specifications
SUPRA STV-LC42790FL
General recommendations for TV LCD LED repair
Repair of the SUPRA STV-LC42790FL TV should begin with a fault diagnosis, which involves a careful examination of the external and internal elements of the device. Visible damage to elements can sometimes indicate the direction of searching for a defect even before the necessary measurements are taken. In some cases, defective elements are visible with the naked eye, for example, charred resistors or swollen sintered capacitors, or electrolytic ones in rectifier filters. The formed ring cracks in the soldering of the terminals of transformers or heating circuit elements are also frequent sources of many malfunctions with a variety of external manifestations.
If the LK-PL420406 power supply module fails, external manifestations may be different, for example, SUPRA STV-LC42790FL does not turn on at all and there is no indication of the control lamps on the front panel. With the same symptoms, the regulator (converter) of the control processor power supply may be faulty. It is advisable to start diagnostics of the power supply module by checking the condition of the electrolytic capacitors of the rectifier filters and the mains fuse. Defective capacitors should be replaced. If the mains fuse is broken, it is necessary to check first of all the power semiconductor elements - rectifier diodes and transistors, which are often found in a breakdown state in such situations.
It should be borne in mind that in the practice of repair, it is extremely rare for key transistors in switching power supplies (SMPS) to fail without reasons that should be looked for by checking other components, for example, a key breakdown can provoke faulty elements of damper circuits, or dried electrolytic capacitors or broken primary resistors power supply circuits involved in the stabilization process. In this case, all semiconductor elements of the strapping of the PWM regulator microcircuit are subject to verification, which it is desirable to check by replacement.
If SUPRA STV-LC42790FL does not have an image, there is sound and the channels are switched, there is a possibility of a malfunction in the HK420LEDM-AH17H panel backlight LED circuit, or their power converter - LED driver. Sometimes, when turned on, the image appears and immediately disappears. In such cases, it is necessary to check the electrolytic capacitors of the power supply filter of the LED driver itself, including in the secondary rectifier of the main power supply unit.
It is often necessary to disassemble the panel to check the health of the LEDs, as well as the contact connections in the connectors and solders.
When trying to detect a break in the LED lines, it should be borne in mind that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.
The motherboard T.MS18VG.72B 12023 must be checked if there is no reaction to the remote control and function buttons, the standby indicator blinks or is on continuously. In such cases, if the converters or power regulators of the microcircuits are working, it may be necessary to update the software.
In some cases, to repair the MB (SSB) board, it may be necessary to replace the Flash 25Q32 chips with new or known good ones. In cases where BGA technologies are used, defects are usually localized by heating.
We remind users again! Attempts to repair the SUPRA STV-LC42790FL TV without proper qualifications and experience can lead to its complete non-repairability!
DOWNLOAD FIRMWARE FOR SPI FLASH -----------> SUPRA LC42790FL , Main: T.MS18VG.72B 12023, Panel: HK420LEDM-AH17H
The appearance of the MainBoard T.MS18VG.72B is shown in the figure below:T.MS18VG.72B
T.MS18VG.72B can be used in TVs:
SUPRA STV-LC42790FL (Panel HK420LEDM-AH17H), SUPRA STV-LC32800WL (Panel HK315WLEDM-BHA4A).
Main features of SUPRA STV-LC42790FL device:
Installed matrix (LED panel) HK420LEDM-AH17H.
Matrix control uses the T420HW08 Timing Controller (T-CON).
The formation of the necessary supply voltages for all nodes of the SUPRA STV-LC42790FL TV is carried out by the LK-PL420406 power supply module, or its analogs.
MainBoard - the main board (motherboard) is a T.MS18VG.72B module, using Flash 25Q32 chips and others.
SUPRA LED TV STV-LC42790FL with LCD HK420LEDM-AH17H, 42 "(107 cm) 16: 9. The required screen brightness of 350 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 standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, MPEG4, MKV, JPEG.
Speaker power 12 W (2x6 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, SCART, RGB, 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, 1920x1080.
The power consumed by the TV in operating mode from the network is 110 watts.
Overall dimensions: 972x642x273 mm.
TV weight: 13.1 kg.
Attention! The HK420LEDM-AH17H panel of the SUPRA STV-LC42790FL 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.
