newbie questions

So I just picked up my 1st venture into this with an upright DK Jr. (Thanks
Atari Patrick). Here are my issues:
1. the monitor has what seems to be some burn in it. It is very light, but
can become more pronounced if I turn up the contrast. It is where the birds
on level 2 fly across (Great for cheating, but I want it gone). Is this a
cap kit or a degaussing fix?
2. the system has a slight buzzing sound that is there even when the sound
is completely off. As soon as the game is turned on, it starts. The sound of
the game is still fine, but the buzzing is annoying. Speaker? sound card?

I'm sure I will have plenty of other questions as time goes on, but I keep
it at a slow pace for now.

Happy Thanksgiving and thanks for your help


Larry