I have just received a new NUC515RYH. I installed 4GB RAM and a SSD without any problem and can boot from a USB thumb drive.
I started with Lubuntu 14.10 x64. It boots up to the desktop but many elements are not painted. In some cases, an element like an icon will be painted when I mouse over that area. I can launch an app but what is shown looks like a frame with transparent content. Again, mousing over will cause SOME elements (e.g. buttons) to be painted. But it's basically unusable.
In order to solve this, I have taken the following steps without success:
* Checked BIOS version. It matches the latest available from the Intel Download Center.
* Reset the BIOS to default settings.
* Checked my USB thumb drive. It boots fine on my i7/HD4000 laptop.
* Checked the HDMI and DisplayPort video outputs on the NUC.
Next I tried Linux Mint 17.1 Cinnamon x64 and that worked a little better but still gobs of screen painting issues. Linux Mint 17.1 Xfce x64 booted to a black screen (worse).
I'm guessing we have a problem with the X drivers and HD 6000 graphics but do not know what to do about it.
Any help greatly appreciated.