So, long story short, I was using the SKR Mini E3 V2 and had a load of weird issues which lead to it not being able to connect via a Raspberry Pi 3B via USB (using OctoPi distribution).
I tried updating firmware and it would connect to the printer but failed whenever I did anything i.e. heating, moving an axis, etc. I eventually managed to find a heating error. I changed the thermistor on the hot end, realized it was complaining about the heated bed so changed that too, then the Pi just wouldn't see the board. I bought a new V3 board and on the first test everything connected fine; it even started heating up and then cut off as it was getting warm. After a couple of attempts to refresh the firmware, it has done the same thing where it won't find the printer. Like an idiot, I had removed the original LCD screen as I would just use OctoPrint as the screen. I am going to check it when I find out what I did with it.
Firstly, is there a way to set the boards back to default, just so the Pi sees either again? Secondly, is there a reasonable firmware that I can download or should I just use the Visual Studio application to rebuild the firmware? Would this even be helpful at this stage?