The structure of the U disk is relatively simple, mainly consisting of a USB plug, a main control chip, a voltage regulator IC (LDO), a crystal oscillator, a flash memory (FLASH), a PCB board, a chip resistor, a capacitor, and a light emitting diode (LED).
USB plug: It is easy to appear and the board is soldered, which makes the U disk unable to be recognized by the computer. If the power supply is soldered, the U disk will not be reflected in the computer. Sometimes the U disk is shaken and recognized on the computer, and the USB port can be judged to be in poor contact. Just fix it to solve the problem.
Regulator IC: Also known as LDO, its input terminal is 5V, and the output is 3V. Some inferior U-disk regulator ICs are small and easily overheated and burned. There is also a USB power supply reversed, which will also cause the regulator IC to burn out. The multimeter can be used to measure its input voltage and output voltage during maintenance. If there is no 3V output, it may be that the regulator IC is broken. However, there is a case where the output voltage is low and the main control is hot. At this time, the main control is burned.
Some U disk will string a 0 ohm protection resistor between USB+5V and the regulator IC. At this time, the regulator IC has no 5V input voltage and it is broken. Now many masters integrate the LDO into the master, so we will see that many USB flash drives do not have an external LDO. They are all USB+5V voltage direct inputs. This situation will change the main control. Www.upan.cc
Crystal oscillator: Most of the early U-disks used 6M crystal oscillators, and now U-disks generally use 12M crystal oscillators. The crystal oscillator is not resistant to falling, so it is a wearing part on the U disk. The best maintenance method is to directly replace the crystal with the same frequency.
The main control chip: the main control chip is responsible for the flash and USB connection, is the core of the U disk, we generally refer to the U disk solution refers to the model of the main control chip. The mass production tool also corresponds to it. Some master chips also need to input 3V voltage to power the FLASH to ensure the normal operation of the flash memory.
FLASH pad: Its role is to fix the flash and connect the flash to the master. After being squeezed by an external force, the flash memory and the pad are in poor contact, and the U disk on the computer cannot be opened, and the file cannot be stored. As long as the pins of the flash are repaired, it can be repaired, that is, we often say drag welding.