Technical description and composition of the THOMSON 32LB120S4 TV, panel type and modules used. The composition of the modules.THOMSON
Model: 32LB120S4
Panel: V296W1-L14 REV.C2
Inverter (backlight): DARFON V144-001 48.V1448.001 / F
PWM Inverter: OZ960
Trans Inverter: 4009A434158
Power Supply (PSU): 54.M2207.011 REV.C:
PWM Power: UC3843A, L65610
MOSFET Power: 20N60C, W12NK807, M101AC
MainBoard: 48.M4001.A00 BENQ, 48.M2520.A00
IC MainBoard: THC63LVDM83A, 4868AA1 4386.11 LK F, MSP 3415G, TDA7490L, CK6694V-0, VPC 3230D C5, AD9883A KST-110
Specifications 32LB120S4
THOMSON 32LB120S4
General recommendations for TV LCD repair
Possible malfunctions
- THOMSON 32LB120S4 does not turn on, indicators on the front panel do not light or flash. The TV does not respond to control buttons and the remote control.
In some cases, the power supply module 54.M2207.011.REV.C: is faulty with similar manifestations. Then we recommend measuring its output voltages and, if they are absent, you should check the serviceability of the power switches (20N60C, W12NK807, M101AC) and rectifier diodes of the converters for a possible short circuit.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in an emergency mode of short circuit without output voltages, and with a short circuit in the elements of the primary circuit, the mains fuse most often breaks off immediately and less often the current sensor in the source of the key.
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) UC3843A, L65610 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 provoked by the power module, or by defects in the inverter, as well as by the skew of 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.
Sometimes, for diagnostic purposes, it is necessary to disable the inverter protection. In such cases, special care must be taken during work, and the protective circuits must be restored immediately after the repair is completed.
- The indicator on the front panel blinks, the TV does not turn on in operating mode, does not respond to the remote control.
Repair or diagnostics of the 48.M4001.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). Often the MB (SSB) board must be replaced in case of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - THC63LVDM83A, 4868AA1 4386.11 LK F, MSP 3415G, TDA7490L, CK6694V-0, VPC 3230D C5, AD9883A KST-110 and replace the failed chips with new ones. Some malfunctions can be associated with the use of BGA soldering technologies in modern Main Board. Usually such defects are detected by local heating of the chip.
The lack of an image in the presence of a signal from THOMSON 32LB120S4 is often caused by a malfunction of the display backlight. Moreover, the problem can be both inside the LCD-panel (matrix) V296W1-L14 REV.C2, 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 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 the main board MainBoard 48.M4001.A00 often 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 should track the passage of LVDS signals from MainBoard 48.M4001.A00, as well as synchronizing signals from T-CON to loops with drivers.
Attention to users! Self-repair of the THOMSON 32LB120S4 TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
Additional MainBoard RepairThe appearance of MainBoard 48.M4001.A00 is shown in the figure below:
48.M4001.A00
External view of the power supply
The main features of the THOMSON 32LB120S4 device:
Installed matrix (LCD panel) V296W1-L14 REV.C2.
The DARFON inverter is used to power the backlight lamps, it is controlled by the OZ960 PWM controller. The transformer 4009A434158 is installed in the inverter converter.
The formation of the necessary supply voltages for all nodes of the THOMSON 32LB120S4 TV is carried out by the power module 54.M2207.011, or its analogs using UC3843A, L65610 microcircuits and power switches of the 20N60C, W12NK807, M101AC type.
MainBoard - the main board (motherboard) is a 48.M4001.A00 module, using THC63LVDM83A, 4868AA1 4386.11 LK F, MSP 3415G, TDA7490L, CK6694V-0, VPC 3230D C5, AD9883A KST-110 and others.
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 32LB120S4 with LCD V296W1-L14, 32 "(81 cm) 16: 9 diagonal. Screen brightness of 550 cd / m² is provided by CCFL (EEFL) lamps. Contrast - the ratio of maximum to minimum brightness is not less than 800: 1. Input HF or video signal is decoded in analog systems PAL, SECAM, NTSC.
Speaker power 40 W (2x20 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, SCART x2, RGB. A headphone jack is provided.
Overall dimensions: 220x956x555 mm.
TV weight: 18.4 kg.
Attention! The V296W1-L14 REV.C2 panel of the THOMSON 32LB120S4 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!