Google Nexus 10 — Continuous Optimising APS

Following the battery going flat and after recharging it the tablet tries to run up but then just continuously tries to optimise around 125 aps.
When it has finished this, after a long time, it simply starts to try to load the system again.
Pressing the Power and volume buttons together will not make it go into fastboot mode so I cannot get to recovery mode, clear cache etc.
Tried changing the battery for a new one but the result is the same.
It looks as if the software /operating system was corrupted when the battery became discharged - perhaps when an update was being loaded.
Is the tablet a write off or is there a way to reload the operating system please.
Thanks for your Attention.
Matty