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When was the last time you remember your device would power on?
Since then, were any major updates installed, or was the device dropped or did it get wet?
I cannot connect to the tablet, since it wont power on.
And theres no answer I can give as of yet, until I ask you more questions to isolate the actual issue from many possible issues.
lets start with this, when you plug the AC adapter into the tablet. Does the charging light come on?
Also, when you press power exactly what happens, do you see the screen flicker or flash or change from black to grey? Anything at all you see or hear when you press power.