Quoted from terryb:Most likely. Check for broken wires to the switch. Get some DeoxIT contact cleaner and give it a good spray before replacing.
Skip the Novus 1, 2 and 3. That's polishing, not cleaning and if you want to polish the playfield there's much better solutions.
I agree with Terry here. I use simple green to clean everything from ramps to playfield.
On the vol down switch, you could try to jump the wires with a paper clip. If you're going to shop the pin, you need a rudimentary understanding of how switches work and are wired and not be afraid if there is some light soldering.