On 25/02/2012 07:10, pepebuho wrote:
It is a Panasonic SA-AK15 mini system. The body (cd changer, tape
deck, tuner) is on a shelf and the speakers (two) are hooked through
long cables on another shelf, atop my bed headboard.

If, after a couple of second after you switch the unit on, there is a
quiet mechanical click. that would indicate a relay (which generally
isolates the speakers). That would be my first port of call, checking
for low contact pressure or tarnished contacts.
Tapping this relay often provides a clue. If the fault always occurs on
both channels simultaneously, then I would suspect that the relay isn't
the cause

It's easier usually to replace the relay than fiddle around trying to
improved the contact arrangements.

I would inspect any ribbon cables especially the flat 'printed' type for
tarnished contact areas on the ends.

Another area in which it might be fruitful to look, is any mechanical
push switches, tho these are becoming rare on modern equipment.

The other possibility is a dry joint (cold solder joint), which would
probably be anywhere in the signal path after the volume control, and
somewhere common to both channels.

HTH

Ron