Engineers who fix electronic equipment have a secret weapon: their nose. They sniff faulty circuit boards to locate overheated and failed. components. Now Hitachi of Japan is taking that trick a step further.
Its US patent application 2004/49983 describes a foil sachet filled with ethanol and sealed with a plug of indium-tin alloy, which melts below 100 °C, and which is small enough to be stuck to any electronic component. If the component overheats, the plug melts and the smell of alcohol warns someone to switch off the device before it catches fire.
