Technical description and composition of the THOMSON T26C81 TV, panel type and modules used. The composition of the modules.THOMSON
Model: T26C81
Chassis / Version: MST739
Panel: HT260WXC-100 // LC260WXE (SB) (V2)
T-CON: HT260WX2100; HX8861-F, RT9955
Inverter (backlight): integrated into PSU
PWM Inverter: UBA2702T
MOSFET Inverter: TK40P03M x4
Trans Inverter: SPI-EEA17-005 11002972 x4
Power Supply (PSU): KIP-L072U04C2-01 34006602 34006643
PWM Power: FSQ0765 (Q0765R)
MainBoard: MST739 35014642 2010.12.28
IC MainBoard: Cpu: MST739KE-LF, Spi Flash: 25Q80, Eeprom: 24C64, 24C04, Audio amp: LA42205
Tuner: AFT1 / 3100G
Specifications T26C81
THOMSON T26C81
General recommendations for TV LCD repair
Possible manifestations of malfunctions
- The THOMSON T26C81 TV does not turn on, does not respond to the remote control and control panel buttons, the indicators do not light up or flash.
Most likely, in this case, the main switching power supply (SMPS) KIP-L072U04C2-01 is faulty. Then we recommend measuring its output voltages and, if they are absent, you should check the serviceability of the power switches and rectifier diodes of the converters for a possible short circuit.
In case of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and in case of a short circuit in the power elements of the primary circuit, the mains fuse and / or the current sensor in the source of the key usually breaks off.
Mos-Fet power switches used in switching power supplies sometimes fail due to a malfunction of any other elements that can disable it in the key mode, or create an excess of the maximum permissible key parameters. These can be elements supplying a PWM regulator, frequency setting or damper circuits, or elements of negative feedback in the stabilization circuit. PWM controllers FSQ0765, in the absence of visible damage or outright short circuits between the terminals, are checked by replacing them with new ones, or knowingly working properly.
- There is no image, there is sound, it reacts to the remote control, the channels are switched. In some cases, the image appears when turned on and disappears immediately.
The defect can be caused by problems in the nodes or elements of the display backlight, or in the power supply of the lamps or the inverter.
If, when diagnosing a malfunction, it is required to turn off 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 they are completed, it is imperative to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- The indicator blinks or is on constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the MST739 motherboard should begin with checking the stabilizers and power converters required to power the microcircuits and matrix. If necessary, you should update or replace the software (software). Sometimes it is necessary to check or replace (if necessary) elements of the MainBoard - Cpu: MST739KE-LF, Spi Flash: 25Q80, Eeprom: 24C64, 24C04, Audio amp: LA42205. In cases where a BGA processor is used, its malfunction is usually detected by a local warm-up method.
If you suspect a malfunction of the AFT1 / 3100G tuner, first of all, you need to make sure that the software is correct, as well as the presence of the necessary levels of supply voltages and pulses of data exchange with the processor via the I2C bus on the corresponding terminals of the tuner.
The lack of an image in the presence of a signal from THOMSON T26C81 is often caused by a malfunction of the display backlight. Moreover, the problem can be both inside the LCD panel (matrix) HT260WXC-100, 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, repairing the backlight requires disassembling the HT260WXC-100 LCD panel - a painstaking process that requires special 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 MST739 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 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 MST739, as well as synchronizing signals from T-CON to loops with drivers.
Owners of the T26C81 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 FIRMWARE FOR SPI FLASH -----------> THOMSON T26C81, Main: MST739 35014642 2010.12.28, Panel: LC260WXE
DOWNLOAD FIRMWARE FOR SPI FLASH -----------> THOMSON T26C81, Main: MST739 35014642 2010.12.28, Panel: HT260WXC-100
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL --> KIP+L072U04C2-01 Power supply
The appearance of the MainBoard MST739 is shown in the figure below:MST739
External view of the power supply
The main features of the THOMSON T26C81 device:
Installed matrix (LCD panel) HT260WXC-100 or LC260WXE (SB) (V2).
Matrix control uses Timing Controller (T-CON) HT260WX2100 ;.
A converter combined with a power supply is used to power the backlight lamps, it is controlled by the UBA2702T PWM controller. The transformer SPI-EEA17-005 11002972 x4 is installed in the inverter converter. TK40P03M x4 keys are used as power elements of the inverter.
The formation of the necessary supply voltages for all nodes of the THOMSON T26C81 TV is carried out by the KIP-L072U04C2-01 power module, or its analogs using FSQ0765 (Q0765R) microcircuits.
MainBoard - the main board (motherboard) is an MST739 module, using chips Cpu: MST739KE-LF, Spi Flash: 25Q80, Eeprom: 24C64, 24C04, Audio amp: LA42205 and others.
The AFT1 / 3100G tuner provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: BOE
Model: HT260WXC-100 CELL
Type: a-Si TFT-LCD, CELL
Diagonal size: 26.0 inch
Resolution: 1366x768, WXGA
Display Mode: TN, Normally White, Transmissive
Active Area: 575.769x323.712 mm
Surface: Antiglare (Haze 25%), Hard coating (3H)
Transmissivity: 6.9% (with Polarizer)
Contrast Ratio: 800: 1
Display Colors: 16.7M (6-bit + Hi-FRC), CIE1931 72%
Response Time: 5 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V
LCD TV THOMSON T26C81 with LCD display HT260WXC-100, diagonal size 26 "(66 cm) format 16: 9. Screen brightness 350 cd / m² provided by CCFL (EEFL) lamps. Contrast - the ratio of maximum to minimum brightness is not less than 900: 1. You can view in high quality HD at a resolution of 1366x768 pixels in 720p standard (HD Ready). Input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Digital signal formation (graphic format) is performed in standards 480i, 480p. , 576i, 576p, 720p, 1080i.
Speaker power 8 W (2x4 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), VGA. A standard VGA (D-Sub 15) connector is used to connect a laptop or computer. This interface supports resolutions: 640x480, 800x600, 1024x768.
Attention! The HT260WXC-100 panel of the THOMSON T26C81 LCD TV is the most expensive component.
Avoid hitting the glass and putting pressure on the screen surface to avoid irreversible damage to the LCD panel!
