Those failed caps 47uF, 63V - in similar HK amp
they were rated 40V 47uF , what is the problem in that area of the
circuit?




I don't know of one in particular. On about 50% of the ones that I see,
there are issues with those caps. They just get replaced as a matter of
course, as part of the repair. Output transistors. Little TO92s. Fuses.
Caps. That's all that goes wrong with them, and that's as deep as I bother
getting in. There are not repeat failure issues, if those parts are all
replaced, and these days, all I am interested in is the commercial angle,
and spending as little of my time on a repair as is required, whilst making
sure that it is actually fixed, and any manufacturer-specified remedial work
has been carried out .

Arfa