[s-cars] Concert Head Unit install

[j.n.tilden at comcast.net]

I finally installed the new Concert head unit in my 1995.5 S6 with a new harness to allow hooking up Ipod inputs. I have removed the CD Changer and the Cell Phone completely.

All went well and it turned on and worked just great for about a week.
Now, I get loud popping on ignition turn on and off.
Popping does not occur when turning on or off the Concert head unit.
Popping does occur when turning on or off the ignition switch, whether the head unit is ON or OFF!

Is this the symptoms of the dreaded Bose capacitor failure?
I seem to recall, but can't find, the article that describes the rework for the Bose amplifiers, I am competent with soldering.

Or is this a function of the Concert radio being different from the Delta?

Thanks,
John
1995.5 S6 Avant
Seattle WA