Technical description and composition of the THOMSON T24C80 TV, panel type and modules used. The composition of the modules.THOMSON LED
Model: T24C80
Panel: M236H1-L01-X
LED driver (backlight): integrated into PSU
PWM LED driver: AZ7500EP
Power Supply (PSU): MLT019L-CJ Rev1.0 KB5150
PWM Power: PWM SOT23-6 (LD7535)
MainBoard: KL24NS80Q / MST739 35014642
IC MainBoard: MST739KE-LF, EN25F80, 24C64, 24C04, LA42205
Tuner: AFT1 / 3100G
Specifications T24C80
THOMSON T24C80
General recommendations for TV LCD LED repair
Possible manifestations of defects
- The THOMSON T24C80 TV does not turn on and does not show any signs of turning on, does not respond to the control buttons and the remote control.
Often in such cases, the MLT019L-CJ power supply module 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 the event of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and in the event 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.
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 regulators (PWM) PWM SOT23-6 (LD7535), if they have no visible damage to the case and an open short circuit between the pins, 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.
Often in such cases, there is no backlighting of the LED panel. The reason may be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
To test the LED strips, in order to open all the transitions of the LEDs, several tens of volts or more are needed; it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED junctions in forward bias, you can sometimes detect the presence of a protective zener diode PN junction by connecting the probes in the opposite direction. If the zener diode is cut off or broken in K / Z, then the LED is faulty and needs to be replaced.
- The TV does not go into operation, does not respond to the remote control. The indicator on the front panel is on or blinking.
Repair or diagnostics of the KL24NS80Q motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). Repair of the board and replacement of microcircuits MST739KE-LF, EN25F80, 24C64, 24C04, LA42205 are performed if the necessary equipment and the corresponding element base are available. Failures associated with the use of BGA soldering technologies can be localized by warming up.
If there is no tuning for terrestrial or cable TV channels, you should make sure that the software is correct, as well as that the supply voltages on the terminals of the AFT1 / 3100G tuner match. It is also necessary to check with an oscilloscope the presence of pulses of data exchange between the tuner and the processor via the I2C bus.
The lack of an image when a signal is present with the THOMSON T24C80 is often caused by a malfunction of the display backlight. Moreover, the problem can be both inside the LCD panel (matrix) M236H1-L01-X, 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, disassembling the LCD panel M236H1-L01-X is required - a painstaking process that requires increased attention and accuracy from the master. 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 KL24NS80Q 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 needs to track the passage of LVDS signals from the MainBoard KL24NS80Q, as well as synchronizing signals from T-CON to loops with drivers.
Once again, we remind TV users: you should not try to repair yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repairs to professionals with sufficient experience in the field of electronic repair.
Additional MainBoard RepairThe appearance of MainBoard KL24NS80Q is shown in the figure below:
KL24NS80Q
The main features of the THOMSON T24C80 device:
Installed matrix (LED-panel) M236H1-L01-X.
A converter combined with a power supply is used to power the backlight LEDs and is controlled by the AZ7500EP PWM controller.
The formation of the necessary supply voltages for all nodes of the THOMSON T24C80 TV is carried out by the MLT019L-CJ power module, or its analogs using PWM SOT23-6 (LD7535) microcircuits.
MainBoard - the main board (motherboard) is a KL24NS80Q module using MST739KE-LF, EN25F80, 24C64, 24C04, LA42205 and others.
The AFT1 / 3100G tuner provides reception of television programs and tuning to channels.
LCD TV THOMSON T24C80 with LCD M236H1-L01-X, 24 "(61 cm) diagonal 16: 9. Screen brightness of 300 cd / m² is provided by CCFL (EEFL) backlighting. Contrast is the ratio of maximum brightness to minimum is not less than 800: 1. The design and technical capabilities of the TV provide viewing in high quality HD at a resolution of 1920x1080 pixels in graphic decomposition according to the standard 1080p (Full HD). The input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Digital signal formation (graphic format) is produced in 480i, 480p, 576i, 576p, 720p, 1080i, 1080p standards.
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 M236H1-L01-X panel of a THOMSON T24C80 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!