How to judge whether the replacement lcd tv screen is broken?
1、 The characteristics of LCD screen damage are: there are two main types: one is physical damage, such as bad spots (bright spots or dark spots) on the screen toilet, black belt or broken screen; The second reason is that there is a failure in the row and column drive circuit or liquid crystal molecule, which results in such phenomena as screen mosaic and vertical band. Although the fault phenomenon after the LCD screen is damaged is similar to some of the fault phenomena after the main board or logic board is damaged, it is easy to see its slight differences by careful observation. Therefore, the above fault is only that the machine does not start, and it cannot be judged that it is a screen problem. The above problems are dealt with as follows:
① If the above machine
How to judge whether the replacement lcd tv screen is broken?
does not start, first check whether the components in the power input circuit are normal, such as power fuse, varistor, and anti-interference circuit components.
② If the above checks are normal, then measure whether the voltage of each group at the output end of the main switch power circuit is normal.
How to judge whether the replacement lcd tv screen is broken?
③ If the above measurements are normal, but the failure of power-on test machine is still, then measure whether the power supply voltage of the main board circuit is normal.
How to judge whether the replacement lcd tv screen is broken?
④ After measuring the power supply voltage of the main board circuit is normal, the problem is to measure whether the voltage of all DC-DC voltage conversion circuit chips on the main board and the output terminal pins to the ground is normal. If there is any abnormality, check the components around the abnormal pin of the chip and try it.