Mac mini gives start-up chimes, fans run, etc, but display says "no signal" was working until this randomly happened?

Question

So, I bought a Mac mini the other day- an "open box" item from Best Buy (Mid 2011, i5 processor, 2GB of RAM running 10.8)
Anyhow, it was working fine all day, i had transfered all my itunes library over to the new Mac mini from my MacBook Pro, and put the programs I wanted onto the mac mini.  (Including plug-ins etc.)  It was working fine, even with 2GB of RAM.
Anyhow, it started to get kind of sluggish, so, I closed all the programs (I assumed this was because it has 2GB of RAM, and I had been pushing it pretty hard all day), and checkd "About this MAC"  Low and behold, it said only one RAM card was in, and it was a 1GB card.  Well, that explains the eventual sluggishness.  Further though, I think it means that once of the RAM slots is messed up.
Problem A) One of the RAM slots/cards is not working properly.
     Problem A.5) I actually have two 2GB sticks of RAM that I pulled out of my 2011 MBP which will work, so, my plan is to upgrade to that RAM once I get the RAM card/slot information squared away.
When I opened up the case to try to switch cards, or address Problem A.5), I noticed that one of the clips for the Mac Mini's RAM was broken.  Perhaps this is why one of the RAM cards was not being read?
Problem B) One of the clips that holds the top RAM card in place is broken.
After I had seen this, (I didn't actually do anything to the RAM, since I know Apple doesn't cover anything if you broke it, so I want to be able to say that I actually didn't touch anything- my guess is the people at Best Buy may have broken it?)  I reconnected the Mac Mini, and was going to get the email and calendar set up, as that was all that was left to get set up.  Oops.
After reconnecting, restarting, everything a few times, the same problem presented itself. 
Problem C) even checking all connections, thoroughly, etc, the Mac Mini chimes on, fans start whirring, etc, but the display reads "no signal."  Tried reconnecting the display, disconnecting, etc, nothing worked.  I knoe the display works because I hooked it up to my MBP and it worked fine.
So, I've got a few issues going on, and an appointment at the Apple Store in Providence, RI today at 7:45 PM.
But, does anyone know anything about any of these issues?  So I may be able to try to tackle some of them on my own before going in?  Or, what to expect from the Apple store?
Thanks guys- any help is greatly appreciated!
-Andy

Answer 1

Hi,
my guess is the people at Best Buy may have broken it?)
My guess is since it was Open Box, somebody bought it, broke it trying to replace RAM, then returned it as they no longer wanted it.
Safe Boot from the HD, (holding Shift key down at bootup), if that doesn't work, try a Verbose boot, CMD+v
But the new Mini's use RAM as VRAM, so I think it's the RAM/slot issue