I have the disc image for the sigma tile, and have written it to the micro sd card, but when I plug it into my monitor via the HDMI I just get a rainbow screen with a little yellow lightning bolt at the top right of my screen. I have tried installing NOOBS onto a different micro SD card and that works fine. Any idea what the problem is with the sigma tile disc image? I downloaded this file from another thread.

 

Just some more information, I am using win32DiskImager, no hash. The file I'm using in the diskImager is 15gb, and it splits my micro sd card into a boot partition, and a 6gb partition that says it needs formatting before I can use it. 

 

 

Jon