U disk LED is not lit

The LED does not light up after inserting a U disk. This situation is the U disk itself does not work. No matter what kind of u disk scheme, want to normal work must meet the following conditions.

1. Power supply. U disk power supply mainly control chip power supply and flash power supply, these two power supply is very important. U disk Internal circuit is simple, if the power supply is abnormal, general insurance inductance damage, or 3.3V voltage regulator block damage. As long as there is no source of power supply, the problem can be solved.

2. Clock. U disk's main control chip needs to work at a certain frequency, but also through the clock signal transmission and flash communication. Therefore, without the clock signal, the work of the master will be terminated. The circuit of the clock is also very simple, the crystal vibration and peripheral circuit inspection can be.

3. master control. If the above two conditions are normal, that is the main chip damage, as long as the replacement chip can be.