How do I get my Nexus 5 stuck at boot animation screen out of it?

[brunozi]

Nexus 5 stuck at boot animation screen

Hi!

Here, I have a nexus 5 that wont boot. It gets stuck at the boot animation screen.

This is my wife's phone. It has no customizations other than downloading apps from google/amazon app stores.

I've tried booting in recovery mode and cleaning the cache partition. But that still didn't change anything.

Is there anything I can do?
Or, is my only hope doing a factory reset? Will that erase everything? Can I do a backup somehow?

Thanks.