Saturday, 30 January 2021

REPAIRING / SERVICING TV THOMSON T43D18SFS-01B

Technical description and composition of the THOMSON T43D18SFS-01B TV, panel type and modules used. The composition of the modules.

THOMSON LED
Model: T43D18SFS-01B

Chassis / Version: MT56T2

Panel: LVF430LGD0 E2 V52 A430LD4DUY-40

LED backlight: 3 strips of 8 led 3V

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

IC MainBoard: CPU, eMMC, DRAM, AUDIO, DC / DC

Tuner: ST55WM-2-E9

Specifications T43D18SFS-01B
THOMSON T43D18SFS-01B
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions

- The THOMSON T43D18SFS-01B 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.

In such cases, you should start looking for a fault in the SHG4301A-101H power supply circuits. It is necessary to measure its output voltages, and if they are absent (full or partial), the serviceability of the power switches (MDF10N60B) of the converters and rectifier diodes should be checked for a possible short circuit.
In case of breakdowns in the secondary circuits, the converter, as a rule, can operate in an emergency mode in a short-circuit mode, and in case of a short circuit in the power elements of the primary circuit, the mains fuse is usually cut off.
Breakdown of Mos-Fet keys used in switching power supplies is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency setting or damper circuits, as well as in negative feedback stabilization. PWM microcircuits (PWM) OB5269CPA and MP1582 are usually checked by replacing them with new ones, or knowingly working properly.

- There is no picture, but there is sound, it reacts to the remote control. Or the image appears when turned on and immediately disappears

As a rule, in such cases there is no display backlight. Usually the cause of the malfunction is in the breakage of the LEDs, or in the connectors of the LED strips 3 strips of 8 led 3V each, but sometimes the LED driver is also faulty.
To identify an open circuit in the LED lines without disassembling the panel, a current source is required. It is impossible to open the junctions connected in series with a simple multimeter; a voltage of several tens of volts is required.



If THOMSON T43D18SFS-01B has no image, but there is sound, often the display backlight LVF430LGD0 E2 V52 A430LD4DUY-40 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 LVF430LGD0 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, light is visible through the holes in the panel case.
In this case, the panel may also be faulty - damage to 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, you need to check the panel supply voltage, the 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 normal limits, it is necessary to trace the passage of LVDS signals from the MainBoard 40-MT56T2-MAF2HG with an oscilloscope, as well as synchronizing signals to the 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 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 (software). In cases of complex MB (SSB) repairs and with the necessary skills and equipment, it may sometimes be necessary to replace its CPU, eMMC, DRAM, AUDIO, DC / DC chips and other possible faulty components. Malfunctions associated with the use of BGA soldering technologies are usually easily diagnosed by the warm-up method.

If there is no reception of TV channels, but the TV is working properly from external devices, first of all, you need to check the supply voltage of the ST55WM-2-E9 tuner and update the software. I2C communication pulses must be monitored with an oscilloscope.

Attention to TV owners! Attempts to repair THOMSON T43D18SFS-01B on your own are not recommended by the manufacturer and can lead to serious negative consequences! 


DOWNLOAD SHG4301A-101H DLBB449 Power supply diagram. ---->   SHG4301A-101H DLBB449 Power supply
.

 

Current limitation. MP3398A. General recommendations:

To reduce the backlight current in LED drivers with an MP3398A controller, 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 6 in SOIC-16 package (8 in SOIC-20 package).
The formula for the inverse proportion of the backlight current in milliamperes and the resistance Rset in kilo-ohms:
I [mA] = 988 / Rset [kOhm].

DOWNLOAD MP3398A  DIAGRAM  /  MANUAL   ------------------>   MP3398A.


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 T43D18SFS-01B device:

Installed matrix (LED-panel) LVF430LGD0 E2 V52 A430LD4DUY-40.
A converter combined with a power supply is used to power the backlight LEDs and 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 T43D18SFS-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, using CPU, eMMC, DRAM, AUDIO, DC / DC chips and others.
The ST55WM-2-E9 tuner provides reception of television programs and tuning to channels.

LED TV THOMSON T43D18SFS-01B with LCD LVF430LGD0, measuring 43 "(109 cm) diagonally 16: 9. The declared brightness of the screen of 220 cd / m2 is provided by modern LED backlighting. The ratio of maximum brightness to minimum (contrast) is not less than 1200: 1. The LCD panel uses a direct backlighting with a rear-mounted LED - Direct LED.
The LVF430LGD0 matrix and MainBoard 40-MT56T2-MAF2HG software realize high quality HD images at a resolution of 1920x1080 pixels in 1080p (Full HD) graphics.
The T43D18SFS-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.
The 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 is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.

The power supply unit is SHG4301A-101H.

Dimensions: with stand 977x624x221 mm, without stand 977x588x91 mm.

TV weight: 7.5 kg.

Attention! The LVF430LGD0 E2 V52 A430LD4DUY-40 panel of the THOMSON T43D18SFS-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.

Once again, I remind THOSE IDIOTS users WANNABE IMPROVISED  INTERNET BULLSHIT FOOLS GUYS  and TV owners:


Self-repair attempts can have serious negative consequences, up to complete non-repairability.