> My old monitor seems to be on it's last legs. The picture will randomly fizzle
> out to a mostly black screen with some garbage lines flickering in the center
> every now and then, and usually if I wait for a few seconds the picture will
> come back. Sometimes though if it takes too long, I smack the top of the
> monitor and that seems to help. What kind of probablem could it be if smacking
> it will fix it,
Loose component somewhere, probably. Not being l33t in the ways of TV-fu, I can't say exactly where, but the fact that you can smack that bitch up into order, it's probably something physical.
> and how difficult would it be to be permanently fixed?
Depends. How big is the monitor?