REPAIRING / SERVICING TV THOMSON T42E53HU

Technical description and composition of the THOMSON T42E53HU TV, panel type and modules used. The composition of the modules.
THOMSON LED
Model: T42E53HU
Chassis / Version: MS82G
Panel: LVF420NEAL ADUW00 V1
LED backlight: 67-H93412-1A0 42E5300
T-CON: T420HW08 V0 XR 42T09-S03 / 04
LED driver (backlight): 40-RT4611-DRB2XG
PWM LED driver: MAP3204T
MOSFET LED driver: AOD4454
Power Supply (PSU): 40-E371C6-PWG1XG PE371C0
PWM Power: VIPER17L, FAN7930, NCP1397AG
MOSFET Power: MDF12N50
MainBoard: 40-MS82G0-MAC2LG
IC MainBoard: SPI Flash: 25Q32
Tuner: 18237 TCL
Control: IR: 40-MT27AL-IRC2LG
Specifications T42E53HU
THOMSON T42E53HU
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- THOMSON T42E53HU TV does not turn on at all. Control lamps do not light up or blink. The TV on the remote control and control panel buttons does not respond.
With such manifestations, the power module 40-E371C6-PWG1XG usually fails. It is necessary to measure its output voltages, and if they are absent (full or partial), the serviceability of the power switches (MDF12N50) of the converters and rectifier diodes should be checked for a possible short circuit.
In case of breakdowns in the secondary circuits of the converter, it can usually work in an emergency mode in a short-circuit mode, and with a short circuit in the power elements of the primary circuit, the mains fuse or current sensor in the source of the key most often breaks off.
Breakdown of Mos-Fet switches used in switching power supplies is often caused by malfunctions of other elements, for example, in the power supply circuit of the PWM regulator, in frequency setting or damper circuits, as well as in negative feedback stabilization. PWM microcircuits (PWM) VIPER17L, FAN7930, NCP1397AG are usually checked by replacing them with new ones, or knowingly working.
- There is no image, there is sound, it reacts to the remote control. Or, immediately after switching on for a second, the image may appear and immediately disappear.
The malfunction in most of these cases is found in the nodes and elements of the LED panel backlight. 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 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.
- 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-MS82G0-MAC2LG 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). In cases of complex repairs of MB (SSB) and with the necessary skills and equipment, it may sometimes be necessary to replace its SPI Flash: 25Q32 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 THOMSON T42E53HU has no picture, but there is sound, often the display backlight LVF420NEAL ADUW00 V1 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 LVF420NEAL 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-MS82G0-MAC2LG 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 trace the passage of LVDS signals from the MainBoard 40-MS82G0-MAC2LG with an oscilloscope, as well as synchronization 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.


In cases where 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 18237 TCL 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.

Users and owners of TVs should remember that attempts to self-repair a THOMSON T42E53HU TV without appropriate qualifications and the necessary experience can lead to serious negative consequences!

Additional MainBoard Repair
The appearance of the MainBoard 40-MS82G0-MAC2LG is shown in the figure below:
40-MS82G0-MAC2LG
40-MS82G0-MAC2LG can be used in TVs:
THOMSON T40E53HU (Panel LVF400NEAL), THOMSON T32E53U (Panel LVF400NE2L).
External view of the power supply
The main features of the THOMSON T42E53HU device:
Installed matrix (LED panel) LVF420NEAL ADUW00 V1.
The matrix control uses the T420HW08 Timing Controller (T-CON).
The LED driver 40-RT4611-DRB2XG is used to power the backlight LEDs and is controlled by the MAP3204T PWM controller. AOD4454 type keys are used as power elements of the LED driver.

The formation of the necessary supply voltages for all nodes of the THOMSON T42E53HU TV is carried out by the 40-E371C6-PWG1XG power module, or its analogs using VIPER17L, FAN7930, NCP1397AG microcircuits and MDF12N50 power switches.
MainBoard - the main board (motherboard) is a 40-MS82G0-MAC2LG module, using SPI Flash chips: 25Q32 and others.
Tuner 18237 TCL provides reception of television programs and tuning to channels.

LED TV THOMSON T42E53HU with LCD LVF420NEAL, diagonal size 42 "(107 cm) 16: 9 format. The declared brightness of the screen of 400 cd / m2 is provided by modern LED backlight LED. The ratio of maximum brightness to minimum (contrast) is not less than 4000 : 1. The LCD panel uses Edge LED backlighting The design and technical capabilities of the TV provide for viewing in high quality HD at a resolution of 1920x1080 pixels in graphic resolution according to the standard 1080p (Full HD). The input high-frequency or video signal is decoded into analog systems PAL, SECAM, NTSC Formation of digital signal (graphic format) is performed in the standards 480i, 480p, 576i, 576p, 720p, 1080i Multimedia formats are supported: MP3, 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), AV x2, component, VGA, HDMI x3, USB. A headphone jack is provided. A standard VGA (D-Sub 15) connector is used to connect a laptop or computer. This interface supports resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080.
The power consumed by the TV from the network in operating mode is not more than 90 watts.
Dimensions: with stand 967x631x226 mm, without stand 967x571x57 mm.
TV weight: 13 kg.
Attention! The LVF420NEAL ADUW00 V1 panel of the THOMSON T42E53HU 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.