I have a N7 2012 that was rooted with stock ROM. I just updated to 4.4 and then decided to sideload 4.42. In middle of running the fastboot with the new image, it just hung at sending 'system' (625382kb). It was there for at least 10 minutes. Ctrl-break didn't do anything, all the keys weren't working in recovery. My only choice was to unplug the device. After unplugging, it reboots to the Google screen and hangs. If I hit the power button, it just returns to the same black screen with Google. It hasn't budged for about 15 minutes now.
I was using these instructions, which worked fine for 4.4.
Is there any way to fix this?
I just booted into recovery and just ran the 4.4 update again. It is working again. PHEW!!!
Um.. going to just hold off on 4.42 update. Wow..