Hum question

What table are we talking about? is it grounded? where is it plugged in?

are you sure hum is minimal while record playing ? or is it just covered by music and mixed to it ?
if you have a hum, you won't really hear what you could hear.
I've been struggling with hum for a long time (it's a long story): war is not over yet but when I win a battle I find out a new world...
and yes, when I lower the tonearm on the record I cannot hear (or better: distinguish) hum anymore.

HAVE YOU TRIED REVERSING PLUGS?? 180 DEGREES. just one at a time... YOU MIGHT HAVE TO USE A CHEATER...BUT IF YOU DO FIND THE HUM...REWIRE THE PLUG AND DUMP THE CHEATER. JUST BE INTERESTED IN REMOVING THE HUM WITH THE CHEATER.

@Stringreen: would you please tell me more about this procedure ? I mean: would you please explain it with different words ? I'm italian and English is not my mother tongue so I must admit I didn't understand what you suggest, but I'm very interested in every possibile means to get rid of hums...
what I don't understand is:
- what do you mean by 'reversing the plugs' 180 degrees ? does this involve disassembling the interconnect cables or what ?
- what's a cheater ?
thank you very much in advance