The purpose of a fuse is to protect electrical equipment from surges in current that would otherwise cause damage. A fuse consists of a tiny wire which either melts or vaporizes when too much current flows through it. The thin wire may be made of aluminum, tin-coated copper or nickel along the middle of it. When a higher current travels along this wire than is normal, the wire will break, instantly cutting off the electrical current. If, for example, the windscreen wipers on your car have stopped working, one of the first things to do is check the fuse. Likewise, if your stereo system has inexplicably stopped working, you may want to check the fuses. Most electronic devices have a fuse. You can buy fuses at different stores like Walmart, Kmart, Radio Shack or hardware stores like Home Hardware. They are pretty easy to find.
To check if a fuse is blown, you will need to pop it out of its holder. It will be held in place by two metal clips around the metal ends of the fuse. Simply slip it out and hold it up to the light. Examine the fuse closely to see if the wire that runs through it has broken. If it has, then the fuse will need replacing. With many fuses, this is not possible to see the wire as there is no glass center allowing you to see it. If this is the case, then simply using an appropriate replacement fuse will allow you to test and see if a blown fuse is the problem or not.
When replacing a fuse, it is imperative that you get the right sort. All fuses have an amperage rating, which should be clearly written on the fuse itself (ex: 3A, 15A, 20A etc...). When you replace a fuse, be sure to get one which has the same amperage. If you are replacing a 3 amp fuse in your stereo system, for example, don’t go and place a 12 amp fuse in it instead! Doing so could cause damage in the event of a power surge. So, to change the fuse, simply slot it into place of the old one. Switch the device on and see if it works. If it does not, then it is not the fuse that is causing the problem. You should read the manual that came with the electronic device you purchased.