I majored in library science. There are several possibilities for this phenomenon you mentioned. First of all, the machine in the school library may really be broken, but this possibility is relatively small, because if the integrated system of the general library is broken, the impression will be great. The borrowing system of school library is generally associated with students' student cards. Generally speaking, the library will not frame you because you don't return the book. There must be a record on your student card. Try to think about whether someone borrowed it, or if you lost your card and someone pretended to borrow it!

I hope you can treat this incident calmly and lose the books in the library as soon as possible! Stick to the stalemate, and you will suffer! Listen to me!