Well....a small correction here: every colour tv has a built in degaussing (otherwise in a few weeks the picture would look like one piece of colourfull art / mess) and what you did (with the on/off) is actually correct.
What's not clear is what is the 'fade' you describe ?
A tube influenced by mangetism gives coloured spots, usually at the outher sides of the screen.
if you take out (turn down) the colour of your tv and the pic is pure black/white and has no coloured spots/fades magnetism isn't the problem.
If the 'fade' means it's not sharp it could be there's dirt behind the glass screen (is the most common cause of this and many tv's are kicked out because of this although the fix is simple: just clean....).
Another reason could be focussing (but this shouldn't 'drift' by itself.
So try this (turning down colour) and fill us in on what the 'fade' looks like....:)