"Everett M. Greene" wrote:

Now, if there are any EEs present, perhaps they can explain
why aircraft radios tend to fail in this manner whereas
nothing much of anything else in the electronic world fails
in a manner to produce heat and smoke. Are avionics units
designed so close to the components' limits to cause this
failure mode? I can understand a transmitter going up in
smoke (while transmitting), but a receiver?

Receivers still contain amplifiers, power regulating transistors, resistors,
diodes, etc. in their circuitry. Failures at the discrete component level
can produce thermal events without increases in main power loads above
circuit breaker limits.

--
Dan
C-172RG at BFM