Recently I was asked to fix a TEAC home receiver/amplifier and I was able to
do so. I don't work on these things often, so I was surprised to find that
all of the RCA jack inputs (CD, tape, etc.) are routed through a couple of
integrated circuits that are essentially analog switches. This is how the
tin-can pushbutton switches on the front panel effectively choose which
inputs to amplify, instead of a direct mechanical switch selection.

One of these analog switch chips shorted out, making the right audio channel
put out much lower volume than the left -- no matter which audio source you
picked. Replacing the chip fixed the problem, but I'm still wondering what
caused the chip to fail in the first place.

My question is this: Because of these analog switch input chips, is it now
a good idea to turn off the power to the amplifier when installing or
removing the input audio cables? Perhaps a static spike zapped the chip; I
dunno. This unit didn't belong to me and I don't know the story of how the
thing failed.

Thanks!