I had a failure in current supply that seemed to affect also the USB life somehow, however can not explain the process, can only say what I hear and what I can see. That is fixed now, but did not fix the main problem here...

Now I can see on D- something happening quit quickly after power-up, then nothing or let us say the same about 100mV staying quit steady. But the plugged and unplugged sound (ding-dong ... dong-ding) does not come.

Darrel: Could you please add a toggle portA.2 (or lata.2) somewhere in your code so that when your program is running I could detect it via that pin (4). That would help to localize, or at least to take me closer to the error source.

I’m kind of lost here, don’t know should that code say ding-dong or not, and don’t know if it is running or is it stuck somewhere.