I would like to post this article to the beginners of "LCD TV Repair": I am not an engineer, not a technician, nor a master, nor a maintenance master. It is just a fan who is engaged in the professional maintenance of LCD TVs in the ordinary maintenance career. To this end, I have accumulated a little personal insight from years of professional maintenance work and summed up a relatively simple fault detection operation method through the hasty sorting and providing a large number of beginners engaged in LCD TV repair, thus faster and better Learn and master the detection and analysis of the "three no" faults of the LCD TV and the operation process, and accurately judge and locate the fault. Windows Pocket Pc,Handheld Mobile Computer,Handheld Pcs,Microsoft Pocket Pc SUNLUX IOT Technology (Guangdong) INC. , https://www.sunluxbarcodereader.com
As a beginner enthusiast, you must theoretically understand and understand the structure of each LCD TV and the name of the machine parts and the roles and functions of the tasks. Sexuality, based on years of maintenance experience, I believe that the "three no" fault has a close and unquestionable direct relationship with the power board of the machine. Therefore, in the liquid crystal color TV, the power board is the supply center of the whole machine energy. It converts utility AC power into one or more sets of DC voltages to provide operating voltage to the TV. Therefore, for the "three no" fault, I must lock the power board as a suspect target to find the entry point for the fault. First check the voltage output of the power strip output (commonly: STB5V, 12V, 24V. Some models also have 16V, 17V, 18V, 20V, etc.) is normal, if some voltage is not normal, then the compliance generated The line and components of the group voltage find its crux. Secondly, the main board backlight lighting control signal "BL_0N, DIM" (brightness control) is very important and indispensable. If the above voltage and backlight lighting control signals are normal and the grounding is good, the high voltage board (light board) and the backlight tube are normal. Then the backlight will definitely light up.
In addition, it should be pointed out that the common LCD TV power board, except STB5V (the reference voltage is also the standby voltage) appears before the second boot, the other voltages can only appear after the second boot, and some models of the power board First provide 12V to the motherboard to work, and then the motherboard sends a power-on command (boot signal) when the other voltages appear, in addition, the power board has two working states, one, high level boot, two, low level boot. Here, I will not elaborate, because the friends of the forum have been frequently discussed in this forum. I hope that the fans of the LCD repair beginners will be fully inspired to further improve their technical level, to guide the practice by theory, and to test by practice. The correctness of the theory, this is the only truth and standard of sex.
The above is my point of view and superficial views. If there is anything wrong, please give advice to the masters, thank you! Below I posted a simple LCD motor repair operation flow picture for the reference of the majority of beginners, use a multimeter to check whether each relevant working voltage and backlight lighting control signal is normal or not. Thank you all!
November 26, 2022