Audio Systems: eliminating hum in retro stereo, family heirloom, radio tape

Question
. its a bell stereo with radio,tape and phono functions ( probably made in the '70's). there is hum on all functions independent of the level of volume chosen. a visual internal check shows no obvious problems (to me- a novice). however the volume control is so stiff i had to use pliers to turn it. in fact repeated turning actually made it stiffer. i can replace the vol potentiometer but is the hum related or do i have two problems?

Answer
What do you mean by retro stereo?

If it's not a performance, mastering or studio component, then it's not worth the time or trouble, unless it's a family heirloom.

If your a novice then my guess is your not a hobbyist. That's what you would need to be if you really want to resuscitate it.