It's probably worth mentioning that generally TurnKey is used as a VM (rather than installed to hardware) and so that's where we put the majority of our efforts and so our hardware support is often not that great.

If you had MineOS working previously on this hardware, perhaps it's better to just reinstall the one that worked before? Having said that, assuming that it was also TurnKey based, I see no reason why this one shouldn't also work?! Although I have no idea how the current ISO you have was built, nor what has been changed by whoever created it. My guess is that this wasn't built by the guy that originally built MineOS...

As I said, MineOS isn't an official TurnKey appliance and it's based on an old version of TurnKey Linux which we no longer officially support. But I'll try to head you in the right direction...

So the default /etc/network/interfaces file that we include in TurnKey v16.x appliances can be seen on GitHub. There haven't been significant changes since the version you have though, so yours by default should look similar.

You can use the pre-installed cli text editor called 'nano' like this:

nano /etc/network/interfaces

If you wish to set a static IP, then you'll want to configure the relevant interface to look something like this. I'll assume eth0, with a static IP of 192.168.1.100, and a gateway/dns (e.g. a consumer grade home router) IP of 192.168.1.1:

auto eth0
iface eth0 inet static
    address 192.168.1.100
    netmask 255.255.255.0
    gateway 192.168.1.1
    dns-nameservers 192.168.1.1

Also as I noted, be sure to remove the top line of that file too.

As to your point about driver, that seems unlikely as you reported in your initial post that you were able to get an IP via DHCP (even though it didn't seem to stick for some reason). For you to be able to get an IP via DHCP, an interface must be working; at least to some degree.

If you're sure that there may be a driver issue, you'll need to find the relevant Debian package that includes the driver for your hardware, download it onto a USB stick (e.g. from another computer), mount the USB stick on this PC and install it with:

dpkg -i /path/to/driver_package.deb

If you keep in mind that TurnKey is based on Debian, searching online should allow you to fill in the gaps on the exact steps needed to do each of those steps (I don't recall the details off the top of my head and I have a ton of other stuff I need to get done...).

If you want to know more about the interfaces file, then assuming that the ISO you have is based on Debian Stretch, then have a look at the interfaces man page. You may also find the Networking section of the Debian manual useful (although note that that is for the current Debian version).

If you manage to work it out, please post back as you'll save the next person a ton of effort.