Nexus 10 completely dead after lollipop update
If you are still able to boot your nexus in fastboot mode(hold down the power button and the volume down button) you can recover it quite straightforward:


Download the desired nexus firmware from here: https://developers.google.com/android/nexus/images#mantaray
Search for a howto flash your nexus 10 via fastboot. Something like this if using windows: http://nexus10root.com/nexus-10-unroot/how-to-unrootunbrick-nexus-10-factory-firmware/


Flashing through fastboot requires an unlocked bootloader - unlocking will remove all your userdata!

If any questions appear just ask ;)