Technical description and composition of the THOMSON T40D18SFS-01B TV, panel type and modules used. The composition of the modules.THOMSON LED
Model: T40D18SFS-01B
Chassis / Version: MT56T2
Panel: LVF400SSDE E2 V12
LED driver (backlight): integrated into PSU
PWM LED driver: MP3398A
MOSFET LED driver: PC015BD
Power Supply (PSU): SHG4301A-101H
PWM Power: OB5269CPAB MP1582
MOSFET Power: MDF10N60B
MainBoard: 40-MT56T2-MAF2HG
Tuner: ST55WM-2-E9
Specifications T40D18SFS-01B
THOMSON T40D18SFS-01B
General recommendations for TV LCD LED repair
Possible manifestations of defects
- The THOMSON T40D18SFS-01B TV does not turn on, does not respond to the remote control and control panel buttons, the indicators do not light up or flash.
In some of these cases, a malfunction is found in the SHG4301A-101H power module. It is necessary to measure its output supply voltages, and if they are absent, check the serviceability of the power switches (MDF10N60B) of converters and rectifier diodes for the probability of breakdown in semiconductor PN junctions.
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.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements, which can disable it in key mode, or provoke an excess of the maximum current or voltage values. These can be circuits supplying the PWM controller, damper or frequency setting circuits, or OOS (negative feedback) elements in the stabilization circuit. PWM controllers (PWM) OB5269CPA and MP1582, in the absence of external damage and a short circuit between the terminals, are checked by replacing them with known good ones.
- There is no picture, there is sound, all other TV functions are working. When turned on, the image may sometimes appear for a second.
In such cases, a malfunction of the LED panel backlighting elements is most likely. Usually the cause of the malfunction is in the breakage of the LEDs, or in the connectors of the LED strips, but sometimes the LED driver is also faulty.
It should be remembered that it is not possible to determine an open circuit in the LED lines without disassembling the panels using a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required. Then you need to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow opening the LED in the forward direction or dual LEds are used, then the PN transition of the emergency zener diode can indirectly serve as an indicator of serviceability. In the event of a malfunction of the LED-a, the PN-junction of the zener diode will either be cut off or broken into the K / Z.
- 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 40-MT56T2-MAF2HG 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 (firmware).
If THOMSON T40D18SFS-01B has no image, but there is sound, often the LVF400SSDE E2 V12 display backlight simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.
Replacing the LEDs requires disassembling the LVF400SSDE LCD panel - a process that requires experience and qualifications from the master. We do not recommend doing such work on your own to the owners of TVs and craftsmen who do not have experience in repairing LCD panels
If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV you can see light through the holes in the panel case.
In this case, the panel may also be faulty - damage to the strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But the main board MainBoard 40-MT56T2-MAF2HG often turns out to be faulty, a software failure is also possible.
Then, first of all, it is necessary to check the panel supply voltage, fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within the normal range, it is necessary to use an oscilloscope to trace the passage of LVDS signals from MainBoard 40-MT56T2-MAF2HG, as well as synchronizing signals to loops with drivers.
Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.
The malfunction of the ST55WM-2-E9 tuner is established after checking the software and all supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be monitored with an oscilloscope.
Remember! Attempts to self-repair the THOMSON T40D18SFS-01B TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!
To reduce the backlight current, you should proportionally increase the total resistance of the resistors relative to the case at the ISET pin of the MP3398A controller. ISET (Current Setting) - Pin 8 in SOIC-20 package or Pin 6 in SOIC-16 package.
The appearance of the MainBoard 40-MT56T2-MAF2HG is shown in the figure below:40-MT56T2-MAF2HG
External view of the power supply
The main features of the THOMSON T40D18SFS-01B device:
Installed matrix (LED panel) LVF400SSDE E2 V12.
A converter combined with a power supply is used to power the backlight LEDs, it is controlled by the MP3398A PWM controller. The keys of the PC015BD type are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the THOMSON T40D18SFS-01B TV is carried out by the SHG4301A-101H power module, or its analogs using OB5269CPAb MP1582 microcircuits and MDF10N60B power switches.
MainBoard - The main board (motherboard) is a 40-MT56T2-MAF2HG module.
The ST55WM-2-E9 tuner provides reception of television programs and tuning to channels.
LED TV THOMSON T40D18SFS-01B with LCD LVF400SSDE, diagonal size 40 "(102 cm) 16: 9 format. Less than 3000: 1 LCD panel uses Direct LED backlighting The design and technical capabilities of the TV allow viewing in high quality HD at a resolution of 1920x1080 pixels in graphics resolution at 1080p (Full HD).
T40D18SFS-01B TV is equipped with SMART software, built-in applications and the ability to work on the Internet. Internet connection can be made via Wi-Fi wireless connection. Supported media formats: MP3, MPEG4, JPEG.
Speaker power 16 W (2x8 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), SCART, HDMI x3, MHL, USB x2, Ethernet (RJ-45), Wi-Fi. A headphone jack is provided. The digital tuner has the ability to receive television channels in the DVB-T, DVB-C, DVB-T2, DVB-S2 standards.
Dimensions: with stand 924x594x222 mm, without stand 924x545x86 mm.
TV weight: 7.2 kg.
Attention! The LVF400SSDE E2 V12 panel of the THOMSON T40D18SFS-01B LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.