Mac mini unable to boot, stuck in grey screen.

Hi,

i have a Mac Mini which I have kept up to date with current version of OS X (Mountain Lion)

After a recent reboot the system won't come up, it just hangs displaying a grey screen.

I have tried:

http://support.apple.com/kb/TS2570

I can boot up the system in single user mode.( https://support.apple.com/kb/ht1492 )

I have done a /sbin/fsck -fy and this works fine. I can browse the file system, the only

strange thing I notice is "BootCacheControl: Unable to open /var/db/BootCache.playlist: 2 No such file or directory".

I have googled quite a lot but I have not managed to find a solution for this, though it is frequently mentioned.

I have tried the normal diagnostics and no hardware error is reported.

I have tried to boot into local recovery, this starts but after a while I end up with the grey screen.

I have tried a Internet recovery and this starts, the screen flashes for a second and I end up with the gray screen

I have tried the different reset methods, such as NVRAM ( http://support.apple.com/kb/HT1379 )

I have tried to reset the SMC ( http://support.apple.com/kb/ht3964 )

I have swapped the RAM modules for other ones.

testing my internet connectivity; speedtest.net reports 15 Mbit downstream and 2 Mbit upstream

Even if I leave my Mac mini on for 12+ hours the internet recovery never finishes, nor am I presented with any options, just the grey screen.

Because the Mac mini doesn't ship with any DVD-media and the Mountain Lion I have bought is through the app store I couldn’t try to boot

from a DVD.

The reason I bought a Mac was to get away from problems which is typically related to computers (Windows). I am running out of ideas here,

please help!

Kind Regards