开云体育

I think some electronics vendors perfume their stuff. I have gotten several appliances which had a soapy perfumy smell without the usual electronic smell which I guess is nice but makes me suspect they sprayed the inside with Febreeze or something that coats the electronics and keeps the smell inside.
I had a failing computer mouse and I recognized the smell of a failing capacitor right away. It's a weirdly fruity, sickly sweet smell. If you want to know what that smells like then just hook up a capacitor backwards.
As for other components, I think they are all loaded with fire retardants so usually you get an overwhelming smell of bromine. It smells similar to chlorine and iodine, which are on the same column in the periodic table. The other components of the smell are usually burnt plastic or burnt epoxy, which I suppose could be identified if you had some practice, but this isn't particularly helpful since almost all components are covered in epoxy or plastic.
Enameled wire has it's own smell which can often be distinguished from the other smells.
Another common smell is just the usual outgassing of cheap solvents used by Chinese manufacturers in their plastics. I have a cheap adjustable wrench which I never touch because the rubber handle cover reeks and I can't wash the smell off my hands after using it. Probably not useful for diagnostic purposes.
A faulty switch, for instance in the flasher in the dash of a car tends to just be singed black plastic which does not really melt since the plastic used in quality switches isn't the kind that melts. The dielectric grease is usually fine and needs a higher temperature than the plastic to break down. The smell is not really like burnt plastic and more like the burning of something organic, but not really like burning leaves or wood. It's an easier smell to live with than the smell of burning plastic.