Thursday, 16 July 2020

REPAIR / SERVICING TV SUPRA STV-LC1926WD

Technical description and composition of the TV SUPRA STV-LC1926WD, type of panel and applicable modules. The composition of the modules.
SUPRA
Model: STV-LC1926WD
Chassis / Version: V1J08
Panel: M185XW01 V0
Inverter (backlight): DP-02-15025 rev2.2.1H
PWM Inverter: DP8600A
Power Supply (PSU): DC 12V, 5A
MainBoard: CVMV26L-A-20
IC MainBoard: TSUMV26KE-LF, Flash: EN25F40-100GCP, EEPROM: K24C32, 24C02C, 74HC4052D, Sound: TDA1517P;
Tuner: F21WT-3BAR-E
Technical Specifications STV-LC1926WD
SUPRA STV-LC1926WD
General repair guidelines for TV LCD
Possible malfunctions
- The SUPRA STV-LC1926WD TV does not turn on. There are no signs of operability. The indicators on the front panel do not shine and do not blink, and the remote control and control buttons do not respond.
Most likely in this case, the main switching power supply (IIPS) DC is faulty. It is necessary to measure the secondary output voltages, and in case of their absence, 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 a short circuit mode, and during short circuit in the elements of the primary circuit, the mains fuse usually breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, power supply, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. The PWM chip can also cause a malfunction of the power switch of the converter and is checked by replacement.
- There is no image, there is sound, there is a reaction to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
These manifestations can be triggered by the power module, or by inverter defects, as well as by the distortion of the currents in the lamps due to their uneven wear. After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, it is necessary to ring in its converter the power switches for breakdown and the secondary windings of the transformers for an open.
If, when diagnosing a malfunction, it is necessary to disable the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required during work, and after their completion, it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- The TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights up constantly or blinks.
Repair or diagnostics of the CVMV26L-A-20 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). 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 chips TSUMV26KE-LF, Flash: EN25F40-100GCP, EEPROM: K24C32, 24C02C, 74HC4052D, Sound: TDA1517P; and other possible malfunctioning components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
The malfunction of the tuner F21WT-3BAR-E is established after checking the software and all the supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be controlled by an oscilloscope.
TV users and owners need to remember that attempts to independently repair a SUPRA STV-LC1926WD TV without the appropriate qualifications and the necessary experience can lead to serious negative consequences!

SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    Supra Main CVMV26L-B-20 Service manual

 The appearance of the MainBoard CVMV26L-A-20 is shown in the figure below:
CVMV26L-A-20
The CVMV26L-A-20 motherboard uses the TSUMV26KE-LF processor (TSUMV36KE-LF), combined with a scaler, SPI FLASH 520Kb ROM and EEPROM 24C02C.
It is advisable to start the MainBoard repair by checking the voltage converters and linear stabilizers necessary to provide power in the operating and standby modes. Check the power supply of the 5V or 12V LCD panel, depending on the type of panel used, it is necessary to measure directly on the LVDS connector. If, in the presence of the necessary supply voltage, the TV does not exit Stand-by mode, does not respond to the remote control and control buttons, update SPI Flash software.
CVMV26L-A-20 can be used in TVs:
SUPRA STV-LC1926WD (Panel M185XW01 V0), SUPRA STV-LC1922WD (Panel MT185GW01 V.0), SUPRA STV-LC2222WD (Panel CLAA215FA), SUPRA STV-LC2622WD (Panel MT215DW01), SUPRA STV-LC1626WD (Panel 720p HD 1600x900), SUPRA STV-LC2417F STV-LC2417FD (Panel M236H1-P01), SUPRA STV-LC1515WD (Panel 720p HD 1366x768), SUPRA STV-LC2422W (Panel M236M1-L01), SUPRA STV-LC2422WD (Panel Panel), THOMSON T24C99H CVMV26L-A (Panel M236H1-L01 Rev.C2).
Main features of the SUPRA STV-LC1926WD device:
Installed matrix (LCD-panel) M185XW01 V0.
To power the backlight, an inverter DP-02-15025 is used, it is controlled by a PWM controller DP8600A.
The formation of the necessary supply voltages for all nodes of the TV SUPRA STV-LC1926WD is carried out by the DC power module, or its analogues.
MainBoard - the main board (motherboard) is a CVMV26L-A-20 module, using TSUMV26KE-LF chips, Flash: EN25F40-100GCP, EEPROM: K24C32, 24C02C, 74HC4052D, Sound: TDA1517P; and others.
The F21WT-3BAR-E tuner provides television reception and channel tuning.
Information from an alternative source:
SUPRA STV-LC1926WD Version V1J08
Panel Type (Matrix): M185XW01 V.0
Motherboard: CVMV26L-A-20, TSUMV26KE-LF, EN25F40-100GCP, K24C32, 24C02C, 74HC4052D, TDA1517P, Tuner: F21WT-3BAR-E
Invertor: DP-02-15025 rev2.2.1H, DP8600A, POWER: DC 12V 5A, Schematic,,
Additional technical information about the panel:
Brand: AUO
Model: M185XW01 V0
Type: a-Si TFT-LCD, Panel
Diagonal size: 18.5 inch
Resolution: 1366x768, WXGA
Display Mode: TN, Normally White, Transmissive
Active Area: 409.8x230.4 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 300 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (6-bit + Hi-FRC), CIE1931 72%
Response Time: 3.6 / 1.4 (Tr / Td)
Frequency: 60Hz
Lamp Type: 2 pcs CCFL Without Driver
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V

 LCD TV SUPRA STV-LC1926WD with LCD M185XW01, diagonal size 19 "(48 cm) 16: 9 format. The brightness of the screen is 300 cd / m² with fluorescent lights CCFL (EEFL). Contrast - the ratio of maximum brightness to minimum is 2000: 1. 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). The input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, WMA, MPEG4, VideoCD, SVCD, JPEG.
The power of the acoustic system of sound 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, S-Video, SCART, RGB, 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.
The power consumed by the TV in the operating mode from the network is 60 watts.
Overall dimensions: 469x402x210 mm.
Mass of the TV: 6.3 kg.

Attention! The M185XW01 V0 panel of a SUPRA STV-LC1926WD LCD TV is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen surface to avoid permanent damage to the LCD panel!