Technical description and composition of the THOMSON 30LB020S4 TV, panel type and modules used. The composition of the modules.THOMSON 16 Lamp CCF
Model: 30LB020S4
Chassis / Version: LCD02TC
Panel: V296W1-L14
T-CON: V296W1-C1 X7
Inverter (backlight): V144-001 48.V1448.001 / F
MOSFET Inverter: 4009A
Power Supply (PSU): 40-LDTV30-PWE2X
PWM Power: L6561D, L5991AD
MOSFET Power: STW20NM50, 12NK80
MainBoard: 40-3026WS-DIG6X
IC MainBoard: MSP3411GPLQFP64, VCT3834A, M29W400, Sil161, K4S643232C, AD9883, TA2024
Tuner: OS04025503 (TDA9886T)
Specifications 30LB020S4
THOMSON 30LB020S4
General recommendations for the repair of TV LCD 16 Lamp CCF
Possible manifestations of malfunctions
- THOMSON 30LB020S4 TV does not turn on. There are no signs of operability. The indicators on the front panel do not light or blink, the TV does not respond to the remote control and control buttons.
In such cases, the fault should be looked for first of all in the 40-LDTV30-PWE2X power module. Then we recommend measuring its output voltages and, if they are absent, you should check the serviceability of the power switches (STW20NM50, 12NK80) 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 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 controller, in frequency setting or damper circuits, as well as in negative feedback stabilization. PWM microcircuits (PWM) L6561D, L5991AD are usually checked by replacing them with new ones, or knowingly working properly.
- There is no picture, but there is sound and reaction to commands from the remote control. Or the image appears immediately after switching on and disappears.
These manifestations can be triggered by the power module, or by defects in the inverter, as well as by skewed currents in the lamps due to their uneven wear. If all the electrolytic capacitors of the filter for the power supply of the inverter are in good working order, you should make sure that the lamps are in good condition, then you need to check the keys of the converter and the secondary windings of the transformers.
If, when diagnosing a malfunction, it is required to turn off the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required during work, and after they are completed, it is imperative to restore the protection circuits for the further safe operation of the TV by the owner in normal mode.
- The TV does not turn on, the indicator signals the standby or operating mode, or blinks.
Repair or diagnostics of the 40-3026WS-DIG6X 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 some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - MSP3411GPLQFP64, VCT3834A, M29W400, Sil161, K4S643232C, AD9883, TA2024 with new or known good ones. In cases where BGA technologies are used, defects are usually localized by heating.
If there is no reception of television channels, but the TV is working properly from external devices, first of all, you need to check the supply voltage of the OS04025503 (TDA9886T) tuner and update the software. I2C communication pulses must be monitored with an oscilloscope.
The lack of an image in the presence of a signal from THOMSON 30LB020S4 is often caused by a malfunction of the display backlight. Moreover, the problem can be both inside the LCD panel (matrix), 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, disassembly of the LCD panel is required - a painstaking process that requires increased attention and accuracy from the master. In such cases, there is a possibility, with the slightest negligence, 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 often the main board MainBoard 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 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, as well as synchronization signals from T-CON to loops with drivers.
Users and owners of TVs should remember that attempts to self-repair a THOMSON 30LB020S4 TV without the appropriate qualifications and the necessary experience can lead to serious negative consequences!
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> THOMSON 30LB020S4 Chassis LCD02TC
The appearance of MainBoard 40-3026WS-DIG6X is shown in the figure below:40-3026WS-DIG6X
External view of the power supply
The main features of the THOMSON 30LB020S4 device:
Installed matrix (16 Lamp CCF-panel) V296W1-L14.
Matrix control uses the Timing Controller (T-CON) V296W1-C1.
A V144-001 inverter is used to power the LEDs. Keys of type 4009A are used as power elements of the inverter.
The formation of the necessary supply voltages for all nodes of the THOMSON 30LB020S4 TV is carried out by the 40-LDTV30-PWE2X power module, or its analogs using L6561D, L5991AD microcircuits and power switches of the STW20NM50, 12NK80 type.
MainBoard - the main board (motherboard) is a 40-3026WS-DIG6X module, using MSP3411GPLQFP64, VCT3834A, M29W400, Sil161, K4S643232C, AD9883, TA2024 and others.
Tuner OS04025503 (TDA9886T) provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: CMO
Model: V296W1-L14
Type: a-Si TFT-LCD, Panel
Diagonal size: 29.5 inch
Resolution: 1280x768, WXGA
Display Mode: Super MVA, Normally Black, Transmissive
Active Area: 643.2x385.92 mm
Surface: Antiglare (Haze 40%), Hard coating (2H), Reflection 2.0% (Max.)
Brightness: 550 cd / m²
Contrast Ratio: 600: 1
Display Colors: 16.7M (8-bit), CIE1931 75%
Response Time: 15/10 (Tr / Td); 16.6 (G to G)
Frequency: 60Hz
Lamp Type: 16 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V
aspect ratio 16: 9. The screen brightness of 450 cd / m² is provided by CCFL (EEFL) lamps. Contrast - the ratio of maximum to minimum brightness is at least 350: 1. The input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC.
Speaker power 12 W (2x6 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, RGB. A headphone jack is provided.
Overall dimensions: 950x575x81 mm.
TV weight: 15 kg.
Attention! The THOMSON 30LB020S4 LCD TV panel is the most expensive component.
Avoid hitting the glass and putting pressure on the screen surface to avoid irreversible damage to the LCD panel!
