I've never done this and I won't be held responsible if something does wrong but someone told me about this method and that it worked pretty well for him.
Remove the contacts from the system, and submerge them in rubbing alcohol. Shake them around in the liquid, etc until it gets all muddy and the contacts are shiny. Using a blow drier, dry the contacts really good before installing them back into the system.
> Yeah, I cleaned them so they should be like brand new, but it doesn't do much.
> I did the same with the NES deck, I used a cleaning kit and when that didn't
> work I used some contact spray.
> > Yeah, I'd like a top-loader too, if just to be the completist. But really,
> > I've done is taken a $2 front loader NES (which can hook into my a/v switch
> > - NICE), and cleaned the contacts a bit using good ol fashioned rubbing
> > This really didn't seem to do much, as a unit that sat in a friend's garage
> > (read: layers of dirt) works 100% with all my games. It's the GAMES that
> > generally seem to go kaput here. Again with the rubbing alcohol, 3 or 4
> > swaps dipped in it per game, and some really vigorous rubbing (if the swap
> > doesnt come out black at least once, you didn't rub hard enuff :). I swear -
> > units so far, and not a single game/console combo that doesn't work without
> > jiggling.
> > > Anybody know where I could get a top-loading nes compatible system? Like a
> > > famicom clone with the ability to play NES games? I've seen them, but I
> > > find a site that sells them!
> > >