Downgrading a new mac mini 2012 from Maverick to Mountain Lion I acquired a new mac mini late 2012 with a fusion drive &amp; a 2,6 Ghz cpu. It came with maverick. 

The machine already came back last week from a mac repear shop where they changed the mother-card because its power turns off on its own while asleep. This did not do much because it still does it. I should either take it back or call apple to have it changed I suppose, except that now...

Although there were warnings not to try to downgrade i.e. Is it possible to go from pre-installed Mavericks to Mountain Lion on my new Macbook Pro?, I wanted to scrape maverick out &amp; replace it by ML just to use Motion 4. I applied the method described here: http://computers.tutsplus.com/tutorials/the-os-x-recovery-partition-what-it-is-why-its-there-and-how-to-remove-it--mac-31796 &amp; erased the recovery HD &amp; the Mac HD to replace it with ML !

Now it seems I'm in dire straits. Even before I wiped Mac HD, erasing the Recovery disk went wrong. It left a partition named "blank" weighting about 16 Mo (originally 650Mo) that doesnt show up in the partition part of disk utility. This "blank" partition also showed up on the desk. 
I've created an ML bootable USB stick with diskmaker but I can't use it, the machine does not want it. I'll spare you the details (blank screen, folder question mark, the globe, asking for the wifi key, error 1005F &amp; s.o.  I also tried the target mode with 2009 mac mini with ML, but I got a message error saying disks were not compatible. Is this because of the fusion drive ? Whatever...

My machine is still under warranty for 2 years &amp; now I'm scared to lose this warranty if I mention my stupid endeavours to apple support. Needless to say, I'm a complete newbee to mac os instal since I rarely change machines. I went into Terminal doing paste &amp; copy just to wipe the recovery hd as mentioned in the method above. 

I think I'm in trouble, my videos helps making ends meet. All I can think off is to bring it back as is to the repear shop &amp; ask them to fix the or replace it with ML. I stumbled on a topic mentioning the recovery hd on you site. to 

Thanks for your precious help
According to the support article listing minimum versions of OS X per computer, your Mac can run OS X 10.8.1


http://support.apple.com/kb/ht1159#Mac_mini


Since you have AppleCare, you can actually call them and ask how to install a specific version of the software and be supported on how to install things.

In a nutshell, you'll have to use Internet Recovery to wipe the drive and get back to the version of OS that shipped with your Mac. From that point, you can download the older OS from the App Store (AppleCare may have to issue you a redemption code for that build if you don't have it for your Apple ID).

From there, you can partition your internal drive and install Mountain Lion on a separate partition or install it onto a USB drive.

At that point, you can restore your data and settings on to Mountain Lion and/or wipe the internal drive booting off the external to finally install Mountain Lion as the only OS on the internal drive.

It's a bit of an exercise, but you can ask here or from Apple for guidance on each step along the way if you get lost.