I have been playing with and trying to get Android TV installed on an old PC as outlined at www.geektillithertz.com with no success. I have installed it on an SSD. When the computer reboots it is not finding a bootable device. I have followed the instructions verbatim to the best of my knowledge. I'm not an expert with linux but when the install asks if you would like to install GRUB does that make the drive bootable? And yes the BIOS is configured to boot to the SSD. Any help would be greatly appreciated.
It looks like you make a bootable external USB that then installs to your SSD, GRUB will make the SSD bootable but the external USB should be bootable on it's own accord. Does the live mode run off the USB or does your computer not even find the device?
As an aside why are you trying to install Android TV on an old PC? it's going to have serious issues with anything DRM based. If you wanted a media centre you could always use Kodi or its ubuntu fork Kodibuntu.