[morzh]

Good ground may help but in teh first place one does not necessarily have it. I certainly don't - I have a regular Earth that is probably a good protection ground but noise-wise.....don't know.
On some radios I saw it helping, on this one it did didley-squat when I connected it.

And this tuned hum - nothing rerally helps except turning that light I spoke of before ON. Andf as I said before I probably know why - the hot and neutral come probably from different cables and form the loop.
It's a guess but I think it is indeed that way (there was an episode that made me suspect it).

Well, I spent this day on line with first Dell Indian team, and then with Cable Retention department. Both somewhat successful.

Now is the time to assemble the speaker back and put teh chassis on.