This is ridiculously annoying, since the SOL allows you to watch console prompts come up but kicks you out if you try to send any characters. rpowering the blade won’t work, so what you have to do is physically pull the blade and pop it back in. While it’s out you might want to take a look at the hardware and make sure everything looks fine.
After inserting the blade, either flip up the LED shield and hit the power button or you can do a rpower -n node on and SOL should come up within a couple seconds.