Nexus 5 stuck on Google logo at boot I recently unpacked, modified, and repacked the boot.img file and flashed it onto my Google Nexus 5.  When I rebooted the device, I was stuck at the Google logo screen.  I can access the recovery mode, but "wipe data/factory reset" did not fix the issue (still stuck on the Google logo screen).  

I also attempted to sideload the stock image found here:

https://developers.google.com/android/nexus/images#hammerhead

Still no luck, as I was receiving "signature verification failure."  The device's bootloader is not unlocked. Anyone have ideas?  I am not concerned with losing personal data, I would be satisfied with just getting it back up and running.
There is nothing to worry. You just have to flash the images properly.

Please follow the steps mentioned in this Android Enthusiasts answer.

The initial bootup usually takes time around 10 to 15 minutes. I'm up and running 5.0.1 without any problems.