Friday, 11 September 2020

REPAIRING / SERVICING TV THOMSON T32E02U-01B

Technical description and composition of the THOMSON T32E02U-01B TV, panel type and modules used. The composition of the modules.
THOMSON LED
Model: T32E02U-01B
Chassis / Version: 3MS82AX
Panel: A320HE2A05-7A
LED driver (backlight): integrated into MainBoard
PWM LED driver: OB3363QPA
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: TP.MS18VG.P78 3MS82AX
IC MainBoard: CPU: MST3M182VGC-LF -Z1, Spi Flash: 25Q32, EEPROM: 24C32, AUDIO: TPA3110LD2
Tuner: R620D
Specifications T49D21SF-01B
THOMSON T32E02U-01B
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- THOMSON T32E02U-01B does not turn on and does not show any signs of operability at all. Does not blink indicators and does not respond to control buttons.
In such cases, the main power supply, the AC / DC converter of the mains voltage, which is combined with the MainBoard TP.MS18VG.P78, may be faulty. Its output voltages should be measured, and if they are absent, check the serviceability of the power switches of the converters and rectifier diodes for the probability of a short circuit.
In case of any breakdown of semiconductors in the secondary circuits, the converter can usually operate normally in an emergency short-circuit mode. There are no output voltages. And with a short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and, less often, the current sensor in the source of the key.
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) PWM SOT23-6, in the absence of external damage and a short circuit between the terminals, are checked by replacing them with a known good one.
- There is no image, there is sound, it reacts to the remote control, the channels are switched. In some cases, the image appears when turned on and disappears immediately.
A malfunction is usually in these cases most likely in the backlight units of the display matrix. 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 TV does not go into operation, does not respond to the remote control. The indicator on the front panel is on or blinking.

 If THOMSON T49D21SF-01B has no picture, but there is sound, often the 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 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 often the main board MainBoard 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 normal limits, it is necessary to trace the passage of LVDS signals from the MainBoard 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.


Repair or diagnostics of the TP.MS18VG.P78 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 some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - CPU: MST3M182VGC-LF -Z1, Spi Flash: 25Q32, EEPROM: 24C32, AUDIO: TPA3110LD2 with new or known working ones. In cases where BGA technologies are used, defects are usually localized by heating.
If the TV operates normally from external devices, but does not tune to TV channels, the R620D tuner may be defective. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the reason for the inoperability of the tuner may be a software failure.
Attention to TV owners! Attempts to repair THOMSON T32E02U-01B on your own are not recommended by the manufacturer and can lead to serious negative consequences!
To reduce the backlight current in LED drivers with OB3363QP (16 pin) controller, the total resistance of the resistors from pin 5 (ISET) to the case should be proportionally increased.


The appearance of MainBoard TP.MS18VG.P78 is shown in the figure below:
TP.MS18VG.P78
TP.MS18VG.P78 can be used in TVs:
THOMSON T42E02HU-01B (Panel LVF420AUDX E8 V1), THOMSON T32ED05U-01B T32ED05U (Panel LVW320CSDX E3 V7), THOMSON T32E02U-01B (Panel A320HE2A05-7A), THOMSON T40ED06HU T40ED06HU-01B (Panel LVF400SSDX E7 V2).
The main features of the THOMSON T32E02U-01B device:
Installed matrix (LED-panel) A320HE2A05-7A.
To power the backlight LEDs, a converter combined with the main board TP.MS18VG.P78 is used, controlled by the OB3363QPA PWM controller.
The power module is combined with the MainBoard and is made according to the AC / DC flyback voltage converter using PWM SOT23-6 microcircuits.
MainBoard - the main board (motherboard) is a TP.MS18VG.P78 module, using CPU chips: MST3M182VGC-LF -Z1, Spi Flash: 25Q32, EEPROM: 24C32, AUDIO: TPA3110LD2 and others.
The R620D tuner provides reception of television programs and tuning to channels.
LED TV THOMSON T49D21SF-01B with LCD, diagonal size 49 "(124 cm) 16: 9 format. The declared brightness of the screen of 300 cd / m2 is provided by modern LED backlight LED. The ratio of maximum brightness to minimum (contrast) is not less 4000: 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 in 1080p (Full HD). Supported media formats: MP3 , MPEG4, HEVC (H.265), Xvid, MKV, JPEG.
Speaker power of 10 W (2x5 W) is provided by two speakers. Uses NICAM stereo processing system and Sound Surround function.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, component, VGA, HDMI x3, USB x2. A headphone jack is provided. The digital tuner has the ability to receive television channels in the DVB-T MPEG4, DVB-C, DVB-T2, DVB-S2 standards.
Overall dimensions: 1106x701x274 mm.
TV weight: 10.7 kg.
Attention! The panel of the THOMSON T49D21SF-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.