Hello
If the tablet can not turn on' im afraid to say that everything you had on your in its internal memory is lost without hope of getting it. To be detailed, special equipment are normally required to perform recovery work on devices that will no longer power on - and now, due to a very large tablet hardware variation, chances are normally very slim that a compatible recovery hardware will be available unless if the model in question has been a big seller. And where the hardware is available, you will normally find that recovery work will cost amost the same amount you paid for the device when new.