Wednesday 9 September 2020

REPAIRING / SERVICING TV THOMSON T32C11U

Technical description and composition of the THOMSON T32C11U TV, panel type and modules used. The composition of the modules.
THOMSON
Model: T32C11U
Chassis / Version: MT23LE
Panel: LTA320AP13
T-CON: A320AP20S4LV0.4; SM4108
Inverter (backlight): SSI320_4UP01 Rev 0.1
Power Supply (PSU): PW152C0 40-P152C0-PWG1
PWM Power: NCP1607, VIPER17L
MOSFET Power: 2SK3455
MainBoard: 40-MT23LE-MAB2XG MT23L-EU - 08-MT23L23-MA300AA
Tuner: F23CT-2DD-E
Control: RC3000E02, IR: 40-MT8223-IRC1XG, 40-MT10L1-KEA1XG
Specifications T32C11U
THOMSON T32C11U
General recommendations for TV LCD repair
Possible manifestations of defects
- The THOMSON T32C11U TV does not turn on, does not respond to the remote control and control panel buttons, does not light or blink indicators.
Often in such cases, the PW152C0 power supply module is faulty. It is necessary to measure its secondary output voltages, and if they are absent, check the power switches (2SK3455) and rectifier diodes in the converters for a short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in short-circuit mode, and in case of short-circuit in the elements of the primary circuit, the mains fuse usually breaks off.
The breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM controllers (PWM) NCP1607, VIPER17L, if they do not have visible damage to the case and an open short circuit between the terminals, are usually checked by replacing.
- There is no image, there is sound, it reacts to the remote control. Or the image may appear for a second when turned on and disappear immediately.
These manifestations can be provoked by the power module, or by defects in the inverter, as well as by the skew of 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, ring the power switches in its converter for breakdown and the secondary windings of the transformers for an open circuit.
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 the further safe operation of the TV by the owner in normal mode.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals the standby mode.
Repair or diagnostics of the 40-MT23LE-MAB2XG 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).
Before replacing the F23CT-2DD-E tuner, if there is no tuning to the channels, you must first check the software and the supply voltage at its terminals. You also need to make sure that the tuner and processor can exchange data via the I2C bus.

 The lack of an image in the presence of a signal from THOMSON T32C11U is often caused by a malfunction of the display backlight. Moreover, the problem can be both inside the LCD panel (matrix) of the LTA320AP13, for example, a malfunction of the CCFL (EEFL) lamps, and outside in their power source - the 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 LTA320AP13 LCD panel - a painstaking process that requires special attention and accuracy from the technician. In such cases, it is possible, with the slightest carelessness, 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 40-MT23LE-MAB2XG 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 the above measurements are within the normal range, then the oscilloscope must track the passage of LVDS signals from MainBoard 40-MT23LE-MAB2XG, as well as synchronizing signals from T-CON to loops with drivers.

Once again, we remind TV users: do not try to repair yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repair to professionals with sufficient experience in the field of electronic repair.

DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    PW152C0 Power supply


 The appearance of MainBoard 40-MT23LE-MAB2XG is shown in the figure below:
40-MT23LE-MAB2XG
40-MT23LE-MAB2XG can be used in TVs:
THOMSON 32HS2040C (Panel LTA320AP13), THOMSON T32C11U (Panel LTA320AP13).
External view of the power supply
The main features of the THOMSON T32C11U device:
Installed matrix (LCD panel) LTA320AP13.
Matrix control uses Timing Controller (T-CON) A320AP20S4LV0.4 ;.
The inverter SSI320_4UP01 is used to power the backlight lamps.
The formation of the necessary supply voltages for all nodes of the THOMSON T32C11U TV is carried out by the PW152C0 power module, or its analogs using NCP1607, VIPER17L microcircuits and 2SK3455 power switches.
MainBoard - The main board (motherboard) is a 40-MT23LE-MAB2XG module.
The F23CT-2DD-E tuner provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTA320AP13
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: APVA, Normally Black, Transmissive
Active Area: 697.68x392.256 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 450 cd / m²
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 8 (G to G)
Frequency: 60Hz
Lamp Type: 4 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V
THOMSON T32C11U LCD TV with LTA320AP13 LCD, 32 "(81 cm) 16: 9 diagonal. 450 cd / m² screen brightness is provided by CCFL (EEFL) backlighting. 4000: 1 dynamic contrast ratio is achieved by special backlight control in depending on the brightness of the scene. It is possible to view in high quality HD at a resolution of 1366x768 pixels in the 720p standard (HD Ready). The input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Digital signal formation (graphic format) is performed in the standards 480i, 480p , 576i, 576p, 720p, 1080i.
Speaker power 4 W (2x2 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
An external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), SCART, VGA, HDMI, USB. A standard VGA (D-Sub 15) connector is used to connect a laptop or computer. This interface supports resolutions: 640x480, 800x600, 1024x768, 1360x768.
The power consumed by the TV from the network in operating mode is not more than 80 watts.
Dimensions: with stand 782x571x185 mm, without stand 782x524x86 mm.
TV weight: 11.1 kg.
Attention! The LTA320AP13 panel of the THOMSON T32C11U 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!