Fuses are designed to protect your electrical system by using small wires that will fail when too much electricity flows through them. As a result, the flow of power will be stopped from reaching your devices.
Many people believe it is possible to detect whether a glass fuse has blown simply by looking at it; this is not always the case.
If you believe that you have a blown fuse, your best bet is to replace it. If this fixes your power problem, then you are finished. If not, you will need to contact a skilled electrician to troubleshoot the problem for you.