This monster of a receiver (a Pioneer SX-950, the size of a small Korean
car) was brought to it's subatomic knees by the tiny 2.2uf tantalum cap
(also attached).

The cap was in the tone control circuit. The problem was that any time you
had the receiver set up for 'normal' operation (tone controls in, filters
out) it would never allow the protection circuit to turn the amp on. If you
took the tone circuits out of the loop, or if you turned on the 'low'
filter, then the protection circuit would turn the amp on. Turning either of
those switches to the other position caused a very loud pop and the
protection circuit cut in.

I had this thing sitting on a shelf for literally a couple years. After the
first year, I bought a service manual for it. Took another year (and change)
before I got to scouring the schematics to find the one component (I pretty
much knew it was a cap) that could cause that problem. A few days ago, I
found it (on the schema). The next day, I got brave enough to tear the beast
down and replace the cap. I replaced it's brother in the opposite channel,
too.

This cap has a clear identity issue.. It thinks it's a 4.4K resistor..

Receiver works pretty well now.. but I do have to tear it down again/some
more to clean all the program switches.

--
Say no to institutionalized interference.
Just say NO to HD/IBOC!