I've recently just bought my first Raspberry Pi 3 Model B, which I wanted to use to set up my own cloud at home.
I followed the steps of an internetblog, which worked very well. I got to the point, where I had to mount my external harddrive and make it writable. After that I rebooted my Pi, but since than, it can't connect to the internet anymore (its connected via a Ethernet cable and worked fine sofar).
The Ethernet cable is plugged in properly, and I've unplugged it multiple times, but it cannot connect to the internet (when I open my router page I can't find it under Ethernet connections, where it originally was).
Problematic, is that I can't connect it via SSH to PuTTY, nor doesn't it react when I plug in a keyboard and a screen (also no connection). So right now, I don't think I have any options of entering any commands.