The acrid smoke emitted when a semiconductor, capacitor, or resistor fails catastrophically due to overvoltage, reverse polarity, or excessive current. The joke among technicians is that electronic components run on magic blue smoke, and once it escapes, the part is dead.
I hooked up the bench supply backward and let the blue smoke out of the microcontroller.
If you smell ozone or burnt epoxy before seeing the smoke, cut the power immediately to save the rest of the board.
Also heard as
- magic smoke
Related terms
Smoke test
The initial application of power to a newly assembled circuit to check for catastrophic failures.
Burn-in
A rigorous testing phase where components operate under stress to force early failures before shipping.
Capacitor plague
A widespread issue in older electronics where poor-quality electrolytic capacitors bulged, leaked, and failed prematurely.