Friday 10 July 2020

REPAIR / SERVICING TV SUPRA STV-LC16740WL

Technical description and composition of the TV SUPRA STV-LC16740WL, type of panel and applicable modules. The composition of the modules.
SUPRA LED
Model: STV-LC16740WL
Chassis / Version: CVMV29L-F V2N08
Panel: NT156WHM-N10 // LTN156AT32 // B156XTN02.2
LED driver (backlight): integrated into T-CON
Power Supply (PSU): Adapter 12V
MainBoard: CVMV29L-F
IC MainBoard: CPU TSUMV59XU-Z1, Flash 25Q32
Tuner: CDT-3NP511-10
Control: IR: 16PT-R
Technical Specifications STV-LC16740WL
SUPRA STV-LC16740WL
General repair guidelines for TV LCD LED
SUPRA STV-LC16740WL, like other televisions, it is advisable to start repairing from inspection of external and internal elements and modules. Specific external damage to some elements can sometimes indicate further actions to determine the malfunction of the TV and localize the defect before the necessary measurements are taken. Electrolytic capacitors of filters with a swollen body, as well as ring cracks or a layer of coal on burned-out resistors formed in the soldered terminals of the heating elements, sometimes tell the repairman the causes of the malfunction and possible consequences.
In the absence of any signs of operability, when the SUPRA STV-LC16740WL does not turn on and does not signal anything with the control lights on the panel, there is a possibility of a malfunction of the TV power module. With the same manifestations, the power regulator of the control processor on the motherboard may be faulty. Diagnostics and repair of the common power supply should always begin with a check of the mains fuse and the condition of the electrolytic capacitors of the secondary rectifier filters. Defective and swollen capacitors should be replaced with new ones. If the fuse breaks, it is advisable to check for a breakdown, first of all, all the power semiconductor elements of the converter and the diode bridge of the network rectifier, as well as the large electrolytic capacitor of the filter of the network rectifier.
The reasons for the breakdown of the power switch in pulsed power supplies (IIPS) can be different, for example, a malfunction of semiconductor elements or electrolytic capacitors in the stabilization circuits of the primary circuit, as well as a failure in the operation of the PWM controller chip or broken resistors in its bundle.
If the SUPRA STV-LC16740WL has no image, there is sound and the channels are switched, there is a possibility of a malfunction in the backlight LED circuit of the B156XTN02.2 panel, or their power converter - LED driver. Sometimes when you turn on the image appears and disappears immediately. In such cases, it is necessary to check the electrolytic capacitors of the power filter of the LED driver itself, including in the secondary rectifier of the main PSU.
In most cases of lack of backlight, it becomes necessary to disassemble the panel in order to check the LEDs, connectors, loops and all contact connections. If one or several LEDs does not work in one line, therefore, they are broken and should be replaced.
An open in the LED lines connected in series cannot be detected with a multimeter or tester without disassembling the panel. To open all the transitions, several tens of volts are needed, and it is best to use a current source for such purposes.
In cases of attempts to repair the CVMV29L-F motherboard, it is necessary to check the operability of the stabilizers or power converters of its microcircuits and, if possible, update the software (software). BGA chips can in most cases be diagnosed by local heating.
In cases of complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its CPU chips TSUMV59XU-Z1, Flash 25Q32 and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
If the TV works normally from external devices, but does not tune into television channels, the tuner CDT-3NP511-10 may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals.
It should be remembered! Attempts to repair the SUPRA STV-LC16740WL TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!

SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    Chassis CVMV29L-F

FIRMWARE FOR SPI FLASH  ----------->   SUPRA STV-LC16740WL, Main: CVMV29L-F, Panel: B156XTN02.2

 The appearance of the MainBoard CVMV29L-F is shown in the figure below:
CVMV29L-F
CVMV29L-F can be used in TVs:
DEXP H24C3000E (Panel CX236DLEDM), DEXP H16B3000ED (Panel N156BGE-L21), DEXP F22B3000E (Panel T215HVN01.1 CX215LEDM), DEXP 16A3000 (Panel N156BGE-L2 1366x768 WXGA ), DEXP 19A3000 (Panel CX185LEDM), DEXP 22A7000 (Panel CX215LEDM), MYSTERY MTV-1628LW (Panel N156BGE-L21), MYSTERY MTV-1629LW (Panel N156BGE-L21), SUPRA STV-LC16741WL (Panel NT156WHM-N12), SUPRA STV-LC16740WL (Panel LTN156AT32).
Main features of the SUPRA STV-LC16740WL device:
Installed matrix (LED-panel) NT156WHM-N10 or LTN156AT32 or B156XTN02.2.
An integrated LED driver is used to power the backlight LEDs.
To power all internal nodes of the SUPRA STV-LC16740WL TV, an external adapter 12V type is used.
MainBoard - the main board (motherboard) is a CVMV29L-F module, using CPU chips TSUMV59XU-Z1, Flash 25Q32 and others.
The tuner CDT-3NP511-10 provides the reception of television programs and tuning to channels.
SUPRA STV-LC16740WL LED TV with LTN156AT32 LCD display, 16 "(41 cm) diagonal size in 16: 9 format. The required screen brightness of 200 cd / m² is provided by LED backlighting. Dynamic contrast ratio of 40,000: 1 is achieved by special control of the LEDs depending on the illuminated areas in the plot, this model uses an LED panel with the end-face illumination LEDs - Edge LED. You can watch broadcasts and movies and images in high quality HD at a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). Input high-frequency or video signal is decoded in analog 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, DivX, MKV , JPEG.
The power of the sound system 6 W (2x3 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, 1360x768.
Overall dimensions: 738x495x210 mm.
Mass of the TV: 6.6 kg.
Attention! The LTN156AT32 panel of a SUPRA STV-LC16740WL 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.