my z2 tablet also have the same problem. i have few time experices. Once turn off the battery then cannot wake up like death as rock. no red light no matter use what method to wake it up.....give up then let it rest atlease 2 days then wake it up again....

Lucky i see my z2 tablet shaking and see it show low battery after 2 day of death sleep. i quick put on charger to give her "food", then everything look fine.

any sifu there got better solution to solve it?