Touch screen do not respond anymore

[LeLutin]

Hi everyone,
since this morning my touch screen do not respond.
I use the tablet last night reading an ebook.
I close the case/protection (don’t know the word, I’m not english) and this morning the touch screen do not work.

When I try to reboot using the power button, the confirmation box (with Stop, Reboot, Air plane mode) come up but I can’t confirm (cause no touch screen).
Is there a way to reset without the screen ?
I’d try pushing the Power and Volume Up together, Power and Volume Down together, it doesnt work.

Some ideas ?

Thks

[Biosham]

User manual says that you need to push power button several seconds to force turn off.

[LeLutin]

That work.
I’d already done that before but It seems that I don’t wait long enough !
Thanks a lot !

Don’t know where the problem come from, maybe the cover…