Clean component connections

Agree that acetone is an excellent solvent but be aware that it will instantly dissolve a remarkable number of things. If you use it be extremely careful to let it touch only the metal parts of connectors. 

Acetone is very toxic---basically lacquer thinner--no need to expose yourself and your house. Caig De-oxit is fine. Try some 70% alcohol first. For the very best connection, use PPT’s Total Contact---see the thread here, under "misc." and under "member review: fantastic new tweak"--extensively recommended.

Word of caution: any solvent can potentially damage plastic compounds and even Windex has on occasion removed lettering from metal panels. 

I used a couple different products back in the '70's -'90's for cleaning switches and enhancing noisy contacts, but for the last 20 years I have been quite happy with Corrosion-X. I've perked up a lot of stereo's and re-animated a lot of sunken RC boats with this stuff...
https://www.amazon.com/Corrosion-X-90102-Anti-Corrosion-Lubricant-16-Ounce/dp/B003HFTI0S/ref=asc_df_B003HFTI0S/?tag=hyprod-20&linkCode=df0&hvadid=309811990469&hvpos=1o1&hvnetw=g&hvrand=15568617493267798440&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9015121&hvtargid=pla-457793615458&psc=1
If it hasn't been opened recently, definately vacuum first.
Unplug what you can, one end at a time, so you can't get confused. Paint the connections with corrossion-x, and re-assemble. Move on to the next part and repeat. Take your time and don't get ahead of yourself. If you cannot paint all the switch mechanisms, you may be able to squirt them, and actuate them repeatedly while they are soaked, and then use compressed air to blow the excess off the switch housing, or it may drip later. I squirt the Corrossion-X in a beer cap and use a solder brush to apply it.
Regards,
Bil

if your interconnection contacts are gold plated, all you need to clean them is isopropyl alcohol and a soft cloth. If they are another metal than you can use De-Oxit. Never use acetone. It dissolves many plastic and rubber components and actually leaves a residue on metal surfaces.