The author has discussed the type of LCD LCD TV backlight tube and its connection. This post continues to demonstrate the compatibility and replacement of liquid crystal LCD backlights and driver boards with the demonstration of the "Static Picture". Everyone knows that LCD LCD TV backlights use two types of (CCFL and EEFL) lamps and multiple types of driver boards to achieve backlight illumination. The author has introduced and discussed these three issues from three aspects: A, the type of backlight high voltage board (light board): <1>, 24 volt power supply type single transformer output driven light board. <2>, 24 volt power supply type multiple transformer output drive type light board. <3>, the power supply high voltage integrated single transformer output drive type light board. <4>, the power supply high voltage integrated type multiple transformer drive output type light board. B, the mutual compatibility of the backlight tube and the driving board and its replacement method: <1>, 24 volt power supply type single transformer high voltage output, single board and double board type high voltage board (suited for EEFL tube). Compatible: Power supply high voltage integrated single transformer high voltage output driven high voltage board. As shown in Figure 1. <2>, 24 volt power supply type, multiple transformer high voltage output driven high voltage boards (suitable for CCFL tubes). Compatible: In-line and bayonet type high voltage boards, as shown in Figure (2). <3>, power supply high voltage integrated type, single transformer high voltage superimposed multiple transformer high voltage output drive type; single board in-line and single board bayonet high voltage board, (suitable for CCFL tube, loop grounding type). Compatible: 24V power supply type, multi-transformer high voltage output drive, single board in-line and single board bayonet high voltage board, as shown in Figure (3). <4>, power supply high voltage integrated type, single transformer high voltage superimposed multi-transformer high voltage output drive type; single report straight plug and single board bayonet high voltage board (suitable for CCFL tube, loop ungrounded type). Compatible: 24V power supply type, multi-transformer high voltage output drive type, single board in-line and single board bayonet high voltage board, as shown in Figure (4). <5>, power supply high voltage integrated type, single transformer high voltage superimposed multi-transformer high voltage output drive type, double board in-line and double board bayonet high voltage board (suitable for CCFL tube). Compatible: 24V power supply type, multi-transformer high voltage output drive type, double board in-line and double board bayonet high voltage board, as shown in Figure (5). <6>, power supply high voltage integrated type, multi-transformer high voltage output drive type, in-line and bayonet high voltage board, as shown in Figure (6). (Applicable to the CCFL tube, as shown in Figure (2)). <7>, power supply high voltage integrated type, single transformer high voltage output high voltage board (adapted to CCFL tube additional capacitive coupling). Compatible: 24V power supply type, single transformer high voltage output driven high voltage board (CCFL tube additional capacitive coupling), as shown in Figure (7). C, the key points of the replacement of the backlight tube and the driver board: According to the above, we know that the LCD TV backlight adopts two types of EEFL tube and CCFL tube. The former is driven by a single transformer (about 1000 volts or so). The backlight is lit, while the latter requires multiple transformers (about 1500 volts or so) to illuminate the backlight. However, the driving plate used between it differs from the structure and its driving voltage. Therefore, in principle, it is impossible to drive a CCFL lamp by driving a single transformer lamp. However, under certain conditions it will not be possible to become possible, which is proof of practice can override this definition, as shown in Figure (7). The author believes that things are divided into two, which are relative, not absolute. Based on this logic, we must have flexible ideas and thinking in the actual maintenance operation, especially when the lamp and the drive plate are replaced, so that we can easily control in the maintenance operation. Secondly, it is necessary to pay special attention to the fact that the backlight tube has a polarity in actual use, that is, "hot end" and "cold end". For convenience, characters such as models are generally printed as hot ends (high voltage end). The character without the character is the cold end (low voltage end), as shown in Figure (8). In the actual connection, the lamp is positive and negative. Special note: Any one of the lamps in each group of lamps may be reversed in sequence, which may cause high voltage protection and cause a "flash off" state! In addition, when replacing the lamp, consider the length of the lamp, the diameter and the hue of the light. When replacing the lamp, pay attention to the type of lamp and the plate and the driving form and circuit mode. Solemn description: The picture shows that all the backlight tubes and their drive boards can be interchanged. The type of picture board and its replacement basically cover all LCD LCD TV backlight types. In summary, the author through the practice of experience combined with the theory and the actual thinking, carefully organized into a document, this original work, no plagiarism; this picture and its discussion is purely personal opinion, for reference only, and Does not represent any point of view or position. See the picture, thank you!
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