Technical description and composition of the THOMSON 20LCDM03B TV, panel type and modules used. The composition of the modules.THOMSON
Model: 20LCDM03B
Chassis / Version: LCD03B
Panel: 4: 3, 800 X 600 (864 X 625 TOTAL)
Inverter (backlight): 48.V0901.001 / B
PWM Inverter: OZ970G
MOSFET Inverter: AO4606
Trans Inverter: T0.0313D // TO.0313D.110
Power Supply (PSU): Adapter 19V 3.42A
MainBoard: LCD03B
IC MainBoard: PW113-20Q, 24C32AN, 20L03B, TD7440D, AD9883, PW1230, HY57V641620HG, VPC323000, SDA555XFL, TDA7266
Tuner: FQ1216MEPT / I H-3
Specifications 20LCDM03B
THOMSON 20LCDM03B
General recommendations for TV LCD repair
Possible manifestations of defects
- THOMSON 20LCDM03B TV does not turn on at all. No response to the remote control and front panel control buttons. Indicator lamps do not light up or flash.
In some of these cases, the problem is found in the adapter power supply module.
This TV model is equipped with an external power supply of the Adapter 19V 3.42A type, which the owner can purchase on his own, and its repair may not always be advisable, however, sometimes it makes some sense to open it and eliminate simple typical defects typical for an SMPS. Then we recommend measuring its output voltages and, if they are absent, you should check the serviceability of the power switches and rectifier diodes of the converters for a possible short circuit.
In case of any breakdowns in the secondary circuits, the converter can operate in an emergency mode of a short circuit, and with a short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key often breaks off.
Breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM controllers (PWM), if they do not have visible damage to the case and an outright short circuit between the terminals, are usually checked by replacement.
- 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. After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, you should ring the power switches in its converter for breakdown and the secondary windings of the transformers for an open.
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 LCD03B 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). When repairing the MB board, you need to check its components PW113-20Q, 24C32AN, 20L03B, TD7440D, AD9883, PW1230, HY57V641620HG, VPC323000, SDA555XFL, TDA7266. Defective elements must be replaced. If chips with BGA soldering technology are used, the problem in its implementation is detected by local heating of the chip.
Before changing the FQ1216MEPT / I H-3 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 terminals 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 display in the presence of a signal from THOMSON 20LCDM03B is often caused by a malfunction of the display backlight. Moreover, the problem can be both inside the LCD panel (matrix) 4: 3, 800 X 600 (864 X 625 TOTAL), for example, a malfunction of 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 4: 3 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 LCD03B also 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 the MainBoard LCD03B, as well as synchronizing signals from the T-CON to the loops with drivers.
Users and owners of TVs need to remember that attempts to self-repair a THOMSON 20LCDM03B TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> THOMSON 20LCDM03B Chassis LCD03B
The appearance of the MainBoard LCD03B is shown in the figure below:LCD03B
The main features of the THOMSON 20LCDM03B device:
Installed matrix (LCD-panel) 4: 3, 800 X 600 (864 X 625 TOTAL).
The inverter 48.V0901.001 is used to power the backlight lamps, it is controlled by the OZ970G PWM controller. The transformer T0.0313D // TO.0313D.110 is installed in the inverter converter. As the power elements of the inverter, keys of the AO4606 type are used.
To power all internal components of the THOMSON 20LCDM03B TV, an external adapter 19V 3.42A is used.
MainBoard - the main board (motherboard) is an LCD03B module, using microcircuits PW113-20Q, 24C32AN, 20L03B, TD7440D, AD9883, PW1230, HY57V641620HG, VPC323000, SDA555XFL, TDA7266 and others.
The FQ1216MEPT / I H-3 tuner provides reception of television programs and tuning to channels.
LCD TV THOMSON 20LCDM03B with LCD 4: 3, 20 "diagonal in 4: 3 format. Input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC.
Speaker power of 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), SCART x2, RGB. A headphone jack is provided.
Attention! 4: 3 panel, 800 X 600 (864 X 625 TOTAL) THOMSON 20LCDM03B 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!
