The sound cuts out for a second or two with a plop, then
comes back again. Giving the side of the set a fairly
vigorous thump with the flat of the hand when the sound
cuts out restores it. The trouble occurs once or sometimes
several times an evening. The set has been examined for
loose wires etc. without anything being found. There is no
disturbance to the picture when the sound goes.
The problem is due to a dry -joint or poor connection.
Check all relevant plugs and sockets, and gently tap and
probe the printed board in the area of the intercarrier sound
and al. circuits. An aerosol freezing compound might help
in locating the fault area.