Back button does not work anymore

who can help me?
since yesterday is on the tablet:
samsung galaxy sm-T530 android 5.0.2 button previous does not work
not the back button.
As further ??

Hello Klaus-Peter Bartels!

Welcome here in the Forum. :)

I have allowed myself time to edit your thread title somewhat. Please be so kind as eighth the next time a more meaningful thread title.

Thank you :)

Hello Klaus,

I'm assuming that you've already started the new device.

Otherwise, this sounds quite strong after hardware failure and in need of repair

What please is a device ??

a device

Yes, the device I have repeatedly turned off.

I think is a hardware damage. I would send the device

Prior to returning I would but then reset pointing to factory settings.

But be careful, all data will be lost.(Danger)