Thursday 17 September 2020

REPAIRING / SERVICING TV SUPRA STV-LC1917W

Technical description and composition of the SUPRA STV-LC1917W TV, panel type and modules used. The composition of the modules.
SUPRA
Model: STV-LC1917W
Chassis / Version: V1K09
Panel: HE185WX1-100
MainBoard: CVMV26L-G
IC MainBoard: CPU: TSUMV26KE-LF, SPI FLASH: EN25F40
Tuner: F21WT-3BAR-E
Control: Login to the service: INPUT-VGA, INPUT 2580.
STV-LC1917W Specifications
SUPRA STV-LC1917W
General recommendations for TV LCD repair
It is advisable to start repairing all electronic devices, including the SUPRA TV based on the V1K09 chassis, with an external examination of its external and internal elements. According to some external signs of a change in the state of some elements, it sometimes becomes possible to make assumptions about the nature of the defect, as well as to determine the further direction of troubleshooting. Experienced repairmen often guess about the causes of the defect and the possible consequences, for example, by ring cracks in the soldering of the element terminals, as well as by swollen capacitors or resistors burnt out to coal dust and other external indirect signs.
Sometimes SUPRA STV-LC1917W TV just won't turn on. No control lamps on the front panel are on or blinking, the TV does not respond to the remote control and does not emit any sounds or any signs of life when turned on. The most likely cause of a malfunction is the failure of the common power module. If it works, check the processor batteries on the SSB (Main Board). Diagnostics and repair of the common power supply should always begin with checking 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 breakdown, first of all, all the power semiconductor elements of the converter and the diode bridge of the mains rectifier, as well as the large electrolytic capacitor of the mains rectifier filter.
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 advisable to check by replacement.
If SUPRA STV-LC1917W has no picture, but there is sound, there is a possibility of a malfunction of the backlight lamps or their power converter. You should also make sure that the electrolytic capacitors of the secondary rectifiers of the common power supply are in good condition. All necessary precautions must be taken when disabling the inverter protection during diagnostics and do not leave it disabled after repair is completed.
On the CVMV26L-G motherboard, in case of a malfunction, you should first check the operability of all stabilizers or power converters of microcircuits and, if necessary, update the software (software). In cases of attempts to repair the MB (SSB) board, it is necessary to check the serviceability of its elements - CPU: TSUMV26KE-LF, SPI FLASH: EN25F40 which may require replacement with new ones. If a BGA processor is installed, there is a possibility that the soldering of the contacts of its pins with the board is broken (detected by warming up).

 The SUPRA STV-LC1917W has no picture when there is a signal, it is often caused by a malfunction of the display backlight. Moreover, the problem can be both inside the LCD panel (matrix) HK185WLCM-BH01H, for example, a malfunction of CCFL (EEFL) lamps, and outside in their power source - an inverter.
Without backlighting, sometimes you can see a barely noticeable image with a certain successful hit of external light on the screen.

Often, to repair the backlight, disassembly of the HK185WLCM-BH01H LCD panel is required - a painstaking process that requires increased attention and accuracy from the master. In such cases, there is a possibility, with the slightest negligence, to damage the glass or loops and the TV may become unrepairable.
We strongly do not recommend doing such work to owners of TVs and craftsmen who do not have experience in repairing LCD panels! Moreover, at home (at the owner's home).

If there is no image in the presence of backlight, the screen becomes slightly lighter when turned on, and if the TV is open, the light from the lamps can be seen through the holes in the panel case.
In this case, there may be a malfunction inside the panel, damage to strips, loops, the T-CON board (Timing Controller) may be defective. But the main board MainBoard CVMV26L-G often turns out to be faulty, a software failure is also possible.
In such cases, the master first of all needs to check the main supply voltage of the panel at the LVDS connector, the fuses on the T-CON board or the panel brackets, as well as the supply and reference voltages for the line and column drivers - VGH, VGL, Vcom.
If all of the above measurements are within the normal range, then the oscilloscope must track the passage of LVDS signals from the MainBoard CVMV26L-G, as well as synchronizing signals from T-CON to loops with drivers.


Owners and users of the SUPRA STV-LC1917W TV need to remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!

DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   SUPRA STV-LC1917W(V1K09), MAIN CVMV26L-G, PANEL HE185WX1-100


 The appearance of the MainBoard CVMV26L-G is shown in the figure below:
CVMV26L-G
The CVMV26L-G motherboard uses a TSUMV26KE-LF (TSUMV36KE-LF) processor, combined with a scaler, SPI FLASH 520Kb and EEPROM 24C02C.
It is advisable to start repairing the MainBoard with checking the voltage converters and linear stabilizers, which are necessary to provide power in operating and standby modes. Check the power supply of the LCD panel 5V or 12V, depending on the type of panel used, it is necessary to measure directly at the LVDS connector. If, with the necessary supply voltages, the TV does not come out of Stand-by mode, does not respond to the remote control and control buttons, you should update the SPI Flash software.
CVMV26L-G can be used in TVs:
FUSION FLTV-16W7 (Panel M156MWR1), FUSION FLTV-19W6D (Panel TM190MFS01), SUPRA STV-LC1917W (Panel HE185WX1-100), SUPRA STV-LC2417F STV-LC2417FD (Panel M236H1-P01).
Main features of SUPRA STV-LC1917W device:
Installed matrix (LCD panel) HE185WX1-100.
The necessary supply voltages for all nodes of the SUPRA STV-LC1917W TV are provided by a switching power supply.
MainBoard - the main board (motherboard) is a CVMV26L-G module, using CPU chips: TSUMV26KE-LF, SPI FLASH: EN25F40 and others.
The F21WT-3BAR-E tuner provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: BOE
Model: HE185WX1-100
Type: a-Si TFT-LCD, CELL
Diagonal size: 18.5 inch
Resolution: 1366x768, WXGA
Display Mode: TN, Normally White, Transmissive
Active Area: 409.8x230.4 mm
Surface: Antiglare (Haze 25%), Hard coating (3H)
Transmissivity: 6.0% (with Polarizer)
Contrast Ratio: 1000: 1
Display Colors: 16.7M (6-bit + Hi-FRC)
Response Time: 1.5 / 3.5 (Tr / Td)
Frequency: 60Hz
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V



LCD TV SUPRA STV-LC1917W with LCD HK185WLCM-BH01H, 19 "(48 cm) 16: 9. Brightness of the screen 250 cd / m² backlit by CCFL (EEFL) fluorescent lamps. Dynamic contrast 4000: 1 achieved by special control of the backlight.It is possible to view broadcasts and films and images in high quality HD at a resolution of 1366x768 pixels in the standard graphic decomposition of 720p (HD Ready) .Input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Graphic processing and digital formation signal occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p.
The power of the sound system of 6 W (2x3 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, S-Video, SCART, VGA, HDMI. 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, 1360x768.
The power consumed by the TV in operating mode from the network is 35 watts.
Dimensions: With stand 461x356x184 mm, Without stand 461x298x77 mm.
TV weight: 4.5 kg.
Attention! SUPRA STV-LC1917W LCD TV panel HK185WLCM-BH01H is the most expensive component.
Avoid hitting the glass and putting pressure on the screen surface to avoid irreversible damage to the LCD panel!