@aaton: The "tap the corners" method is a way to do a factory reset. The instructions are at
https://wiki.mobileread.com/wiki/Kob...ing_squares.22.
Leave it charging for a while. And also try to start it while connected to power. Depending on how long since it was used and charged, the battery might be dead.
Otherwise the reimaging the card is what is needed. I have sent you a PM with the link.