[Drake] AC4 typical failure???

[Dave Edwards]

While typing on the 'puter, I heard a buzz!!
This time, its NOT from my head!
It seemed my AC4 that was powering the TR4 was buzzing (audible AC hum) I
also could smell the typical burnt component smell. It also felt a bit warm
to the touch. The rig was still working great though!!
I turned it off, and will check it out closer tonight.
Anyone have any ideas what usually goes south?
I always hear others having difficulties locating caps that will fit, and
fortunately up until now I did not have to join the search.
Anyone "been there, done that"??
Thanks.....Dave