What make a USB port not read?

Answer 1

Many different factors can make your USB port to not function. If the port is external, then something simple such a the right drivers from the manufacturer's web site can resolve your problem, this can also be the case with internal ones with a new operating system, but not as often. USB port, as a part of any technology is prone to eventual breaking, as in hardware malfunction. Also, to better assist this type of a question, more specific details must be presented, as in what kind (internal, external), age of the port, previous experience with this port, operating system, type of use, hardware used on, and other specifics. This question is very broad, hence no specific answer can be derived. So, based on the lack of detail in the question, try finding drivers for the port and installing them, restart your system, and see if that helps. If the port just suddenly broke, then try blowing some dust out, after opening the hardware*, at your own risk. *(all responsibility waived by the answer contributor and the respectable hosting site).