Bob wrote:

Kurt: I had gone on holidays for about 3 weeks and disconnected
antenna and power. When I powered it up all I got was a line of dots
and no audio. I called a few dealers but none were familiar with the
problem.
Next day I turned it on and I got audio for about one minute but
as soon as I turned the volume up more than half way the dots
reappeared and the audio was dead. Another day went by and I tried
again. This time the radio stayed on and would work normally but an
increase in volume knocked it out again.
On the third day it worked normally and has ever since. I do not
unplug it except briefly to move it from one spot in the house to
another.
I have no idea why this glitch happened.
Hope yours responds as easily.
Regards, Bob

At a guess. It could be condensation which has dried out when you return
home and restart the central heating ect.

--
John