What reset have you done? Just pressed the pinhole reset button? Or a factory reset using the light button? And have you charged it?
You can probably will need to do a factory reset. Instructions to so so are at
https://help.kobo.com/hc/en-us/artic...-your-Kobo-Glo.
It's likely that the problem is a failing SD card. You might need to replace it and restore an image to it to get the device going.