Typical defects of LCD panels
2017-02-04
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In this occasion we are going to describe the mistakes that are typical or current in the displays of liquid crystal
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Many are the problems which we meet in the TV of LCD and in Repair LCD, we believe that to be able to distinguish from which it proceeds the breakdown is very important. In this occasion we are going to describe the mistakes that are typical or current in the displays of liquid crystal.

To clarify little concepts we include to the T-CON (control of times) like part of the panel although we will try to add that defects correspond to a breakdown in this badge and which to the proper display.

1. The most common defect in a LCD panel is when it is struck, since it is very current that this happens today. Often it is a blow accidentally, other times the children playing the wi from which the control escapes and is going to stop directly to the TV.



We show you a blow in a display, as is observed in the photo that there is a point of impact similar to any normal crystal and from the same one salt a series of threads that are becoming bigger if we press. The boss in all the blows is the same, a point of impact and lines in the image.

2. Other times we meet darker shaded areas in the image that are more accented when the TV is cold and that are disappearing as the panel warms up. This is other of the common mistakes in the LCD panels. Also it can be that these shades take color tonalities, can predominate over the red or green one.




Colors lines or in tone of gray when the device is cold it is another panel symptom in bad conditions. As in the previous case as the display goes warming up the mistake is disappearing.



3. One of the mistakes that more take us to trick is the so called solarización, and we say that it can be deceitful because it can be provoked for several motives:



- The first of these reasons can be a bad configuration of the features of the TV, this is adjusted from the Service Mode and sometimes are arranged with a software update. On the other hand this flaw could also be caused by a fault in the scaler of the mainboard but is the least frequent

- Another bug that can cause solarization is a defect in the LVDS cable, this is corrected by changing the cable and sometimes securing it with silicone or some material similar.
- Finally this fault may be caused by a fault in the plate T-with. These plates sometimes can be repaired and other no. Lately is failing in these an integrated called ACE15 that is creating problems of solarization. Replacing this circuit solves the problem. If we are not able to repair will need to change the T-with complete.




4. Screen with retroiluminación but without image or black screen. This is a problem that normally is generated in the T-CON for lack of some of the feedings. The most normal thing is that there is missing the general tension of feeding of this badge that is usually of 12V or 5V. In this case the tension usually comes for the cable LVDS (for one of its ends) but in the badge there is a fuse that one usually marks like F1 in format SMD that is opened and gives place to this breakdown with black screen. If there is no any more problem the fuse changes and the TV is seen normally. At the worst we put the fuse and he opens, this happens for some short circuit later to the fuse, sometimes some condenser crossed SMD and other times some semiconductor.



Other times the problem can be for the internal feedings of the proper T-CON. There usually exists a circuit converter DC/DC that from the entry tension generates several tensions for the rest of the circuits. If some absence of these tensions will give place to a breakdown. In the video we can see the way of measuring these tensions.

5. Also it is possible to find us with the illuminated but completely white or greyish screen. This error is usually provoked by a breakdown in the T-Con. Also it can happen that the TV lights well and as the sheen goes warming up rises gradually only until the whole completely white screen stays, this case also is usually provoked by a breakdown in the T-Con.



6. A mistake that we have usually been on screens of less than 26 inches is that the screen appears with gray and streaky tonality. According to vá warming the image appears. This mistake is typical of the panel of liquid crystal.

7. Flex. Another error that it is possible to correct being some handyman is when colors lines appear on the whole screen or her part occasionally. Other times one sees quite randomly. This mistake disappears pressing the flex of connection of the same liquid crystal. The same ones are of flexible plastic and they are given from the crystal to the plaquita of connections of the display.



Sometimes they become alienated and simply in spite of pressing with the finger appears again the image. The solution to this is to put some gum or seemed material that it presses on the flex. Clear it is that it is necessary to dismantle the metallic frame of the display to gain access to this area.

We believe that these are the most common mistakes but we leave the article opened for possible suggestions of typical breakdowns in the displays of LCD.

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