Dead Tab2 - Please Help

Hi,

My tab 2 (10.1) appears to have gone from fully functioning to dead as a doornail for no obvious reason (no signs of life, not recognised or even acknowledged by PC) the battery is sound and 50% charged but the unit will not respond at all even with a known good battery fitted.

I've tried all variations on charging, button pushing and disconnecting the battery all to no avail.

Any thoughts/advice would be most gratefully received.

Thanks.

P.S, the tablet was rooted and running Cyanogenmod flawlessly for 18 months at least.