I just got a brand new mid-2012 13" MBP, with the 2.5 i5. It is model 9,2 and runs Yosemite 10.10.2 Last week I upgraded the 4gb of ram to Crucial 8gb - I am not sure if this has anything to do with it but I feel full disclosure is best. A couple days ago I noticed that during normal use the laptop will make a click sound that, to me, sounds mechanical and almost like the optical drive. It's just a singular, mechanical-like clicking that sounds almost like one of the clicks you get from the drive when you insert or eject a disc. It occurs at random intervals (or just not at all), and I noticed that it seems to happen more after the computer wakes up from hibernation mode. The system does not react or anything to this click - it's just a sound with no other accompanying symptoms. Please note that I am aware of the motion sensor and this is not it - I can trigger the sensor and it sounds much different/quieter. I feel like it could be the optical drive because it seems like it comes from that general area. The HDD is down in the right bottom corner and this sounds like its coming from under the keyboard on the right side. I've checked SMART status - verified. Did a hardware check. Results all positive. I don't think it is the HDD. Does anyone else know what I'm talking about? And if so, is it an issue? I really don't want to return the computer because I've already installed MS Office and I will be up to my neck in work for the next few weeks so I really can't afford any downtime. Thanks a bunch for any help.