The corbenik GitHub page has all of the setup instructions. You will have to download a couple of files to get it working.Holding R while booting on corbenik doesn't do anything. Also worth noting is that the backlight doesn't turn on with corbenik, but it does with Luma3DS.
Yeah, this sounds like a hardware fault. Not really fixable unless you really know what you are doing.I've been reading and noticed that, i managed to run the firmware (the files weren't in the right folders), it boots but still black screens and blue LED...