Mac SE/30 making zipping and buzzing noises

[David Griffith]

On March 20, 2015 9:52:14 AM PDT, "drlegendre ." <drlegendre at gmail.com> wrote:
> In the meantime, have you re-soldered the power connections to the
> analog
> board? There's a group of them, large-ish pins (might be a connector
> body,
> don't totally recall), which tend to develop near-invisible cracks in
> the
> joints where they meet the board.
> 
> AFAIK the issue is common to all of the classic compact Macs, and it
> can
> cause all sorts of odd problems.
> 
> On Fri, Mar 20, 2015 at 1:27 AM, Terry Stewart
> <terry at webweavers.co.nz>
> wrote:
> 
> > Yes it sounds like caps Dave.  A very common issue with those
> machines.
> >
> > Terry (Tez )
> > On 20/03/2015 6:39 PM, <dave at 661.org> wrote:
> >
> > >
> > > I'm gradually restoring a Mac SE/30.  Today I got a new PRAM
> battery and
> > > installed it.  There was no battery leakage, so I'm good there. 
> The
> > > machine seems to run just fine.  The big problem now is that even
> though
> > > nothing should be emitted from the speaker, I'm getting zips,
> buzzes, and
> > > burbles from it depending on what the computer is doing at the
> time.  I'm
> > > quite sure the the sound circuitry is somehow picking up RF noise
> from
> > the
> > > system bus.  What does this symptom indicate?  Should I recap the
> whole
> > > machine?
> > >
> > > --
> > > David Griffith
> > > dave at 661.org
> > >
> > > A: Because it fouls the order in which people normally read text.
> > > Q: Why is top-posting such a bad thing?
> > > A: Top-posting.
> > > Q: What is the most annoying thing in e-mail?
> > >
> >

Would that be the cause of a flicker in the crt? 
-- 
David Griffith
dave at 661.org