I have a Mac Mini that I bought used from a forum member earlier this year. It's under warranty until mid October and I'm considering buying Applecare to get the additional 2 years of warranty. My question is this: The seller had opened it up to upgrade the RAM. Is there a chance that Apple may not honor service as a result? Should I open it up to make sure there was no visible damage that may prompt them to deny any service? I have heard that the clips inside can break fairly easy when opening it. Would something as simple as that be enough for them to deny service? I ask because the fan has been making the occasional chirping sound like a cricket and I figure that even if I have to send them my Mini now under warranty, I may want Applecare to cover my butt in case another problem come up after this is fixed. The price is good for Applecare on ebay, so I figure it'd be cheaper to get it than to have to pay for parts down the road if needed. Plus if I decide to sell it ever I figure AC would be a plus.