Possibly bricked phone
So I tried to safestrap cm10.1 onto my Droid 4. But, I was much more familiar with a previous version, not with the touch interface and stuff. I did what I thought I had to do: Create a partition, install the zip to it, reboot.
But, to my horror, when I rebooted, I was greeted with a black screen (backlit). I couldn't turn off the phone by holding down the power button either. I had this problem once with my Droid 3, and I 'solved' it by just taking the battery out. But I know things are much more 'locked-down' back there with the Droid 4, so I didn't want to do that.
After a little while, the thing just ran out of batteries. I was hoping to charge it up again. When I plugged it into a wall, I got the little battery icon, which I thought was definitely good news. But now I can't even turn it on, or get my computer to charge it!
UPDATE: I'm going to try using fastboot