Technical description and composition of the THOMSON 30LB120S4 TV, panel type and modules used. The composition of the modules.THOMSON
Model: 30LB120S4
Panel: V296W1-L14
T-CON: V296W1-C1 X7
Inverter (backlight): V144-001
PWM Inverter: OZ960G
MOSFET Inverter: FDS8958 2npn pnp transistor
Trans Inverter: 4009A453077 684 om
Power Supply (PSU): 48.B0090.001-A (54.M2207.011)
MainBoard: 48.M4618.A00, Audio 48.M2520.A00, 48.M3022.S11
Tuner: PM820160C
Control: IR: 48.M2302.A00
Specifications 30LB120S4
THOMSON 30LB120S4
General recommendations for TV LCD repair
Possible manifestations of malfunctions
- The THOMSON 30LB120S4 TV does not turn on, does not respond to the remote control and control panel buttons, the indicators do not light up or flash.
Usually, with similar manifestations, a defect is caused by faulty elements in the main power module 48.B0090.001-A. Its output voltages should be measured and, in their absence, the power switches and rectifier diodes should be checked for the probability of a short circuit in the converters.
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 power switches used in switching power supplies sometimes fail due to a malfunction of any other elements that can disable it in the key mode, or create an excess of the maximum permissible key parameters. These can be elements supplying a PWM regulator, frequency setting or damper circuits, or elements of negative feedback in the stabilization circuit. PWM controllers, in the absence of visible damage or outright short circuits between the terminals, are 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.
The defect can be caused by problems in the nodes or elements of the display backlight, or in the power supply of the lamps or the inverter.
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 indicator blinks or is on constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the 48.M4618.A00 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).
Before changing the PM820160C tuner, if it is not possible to tune to TV channels, you should make sure that there are supply voltages, which must be measured at the corresponding tuner pins and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be monitored with an oscilloscope.
The lack of an image in the presence of a signal from THOMSON 30LB120S4 is often caused by a malfunction of the display backlight. Moreover, the problem can be both inside the LCD panel (matrix) V296W1-L14, for example, a malfunction of the CCFL (EEFL) lamps, and outside in their power source - the 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 V296W1-L14 LCD panel is required - a painstaking process that requires special 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 48.M4618.A00 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 MainBoard 48.M4618.A00, as well as synchronizing signals from T-CON to loops with drivers.
Owners and users of the THOMSON 30LB120S4 TV should remember that self-repair without special knowledge, skills and qualifications may be fraught with negative consequences that can lead to complete non-repairability of the device!
The appearance of MainBoard 48.M4618.A00 is shown in the figure below:
48.M4618.A00
External view of the power supply
The main features of the THOMSON 30LB120S4 device:
Installed matrix (LCD panel) V296W1-L14.
Matrix control uses the Timing Controller (T-CON) V296W1-C1.
The inverter V144-001 is used to power the backlight lamps, it is controlled by the OZ960G PWM controller. The transformer 4009A453077 684 om is installed in the inverter converter. The switches of the FDS8958 2npn pnp transistor type are used as power elements of the inverter.
The formation of the necessary supply voltages for all nodes of the THOMSON 30LB120S4 TV is carried out by the 48.B0090.001-A power module, or its analogs.
MainBoard - the main board (motherboard) is module 48.M4618.A00.
The PM820160C tuner provides TV reception and channel tuning.
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
LCD TV THOMSON 30LB120S4 with LCD V296W1-L14, diagonal size 30 "16: 9. Screen brightness 550 cd / m² is provided by CCFL (EEFL) lamps. Contrast - the ratio of maximum brightness to minimum is at least 600: 1 The input high frequency or video signal is decoded in analog systems PAL, SECAM, NTSC.
Speaker power 40 W (2 x 20 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, component, SCART x2, RGB, VGA, DVI. A headphone jack is provided.
Overall dimensions: 892x529x220 mm.
TV weight: 19.8 kg.
Attention! The V296W1-L14 panel of the THOMSON 30LB120S4 LCD TV is the most expensive component.
Avoid hitting the glass and putting pressure on the screen surface to avoid irreversible damage to the LCD panel!
