I was on rooted 4.2.2, been wanting to un-root it forever but dreaded the idea of it failing. Well, It did fail. I was unrooting it via nexus root toolkit, using drivers adb, and hit flasth stock + unroot, selected the most recent: 4.4.3 build KTU84L
MSDOS prompt got to "sending 'system' (731040 KB)... And it sat here for about 2 hours, after that I pushed some buttons, trying to see if it was responsive any and then unpluged it. At that point it said FAILED, data transfer failur, too many links.. and the script ended.
On the android boot loader screen it said.. "downloading" this entire time, with no update. -- It appeared to be frozen.
So now I have access to the Google loading screen and if I press volume keys and power I can get into the: bootloader, green android laying down.
in red text- Fastboot Mode
mako, mako 8gb, hw vers. rev_11, bootloader version - MAK0Z30d, baseband vers., carrier info none, serian number, SIGNING - production
SECURE BOOT - enabled, Lock State - unlocked.
Pushing down volume, I can access restart bootloader, recovery mode, and power off. and then the Start pic.
No idea what to do now that I have no drivers to load the device for WugFresh Nexus Root toolkit v1.8.3
Also, clicking *Restart bootloader apears to just reload that same screen, and Recovery mode loads an android laying down with red ! triangle. The green start just loads the google logo again.