Failed Fuse Indicator

You switch it on and... ping! Or perhaps a gentle ‘pffft’ or just silence, but nothing more after that. Who hasn’t had this experience at some time? The usual suspect is the fuse. In the same way the normal ‘quick fix’ is to change the fuse for another one, even though this is not really advisable without knowing the precise cause of failure. But what else can you do when you’re far away from the electronics lab? Well, try some simple checks. Is the fuse really defective — and if there are several, which one? Not easy to determine without testgear. Unless you have a built-in failure indicator...I