Ok, found what the problem was. After playing with the multi meter for a few minutes I realised that my PC PSU (converted to work for the A500+) had the -12V not connected correctly!!! Put in everything in place a the sound is back on.
From one side I am happy since all is working, however I don't know if turning the Amiga without the -12V for these last few days may have damaged something!! The truth is that apart the sound all seemed to be working fine!!
I think the -12V is strictly for the audio circuit, so no damage would have been done.
