I knew I was forgetting something. You're right - I first used the alcohol, but then I applied DeoxIT and DeoxIT Gold.
DeoxIT® D-Series contact cleaner dissolves oxides and sulfides that form on metal surfaces. This restores the contact’s integrity and leaves a thin microscopic layer that protects the metal. Special additives improve conductivity and prevent dissolved oxides from re-attaching, keeping them in...
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DEOXIT® GOLD G-SERIES – CONTACT ENHANCER, CONDITIONER & PROTECTOR Maximize New System Performance and Critical Applications DeoxIT® Gold G-Series (forme ...
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At work, I might've just used alcohol, since I didn't have deoxIT there. I'm 90% sure I also cleaned that side of a couple CPUs, there.
Eh, you don't need to be
too precious. Just make sure not to use too much force. Worst case scenario would be the paper/cloth catches the edge of one of the contacts, or you wipe it too hard with something too abrasive and remove some of the gold plating. I'm not really sure about the legitimacy of the latter concern, but gold is soft and the plating is very thin.
I wasn't all that careful, since it was an old i3. And, yet, it still worked fine.