Kobo Clara HD doesn't turn on

I replaced the battery in my Kobo Clara HD yesterday. After replacing the battery the screen just reads Powered Off. When I push the power button, the power LED comes on, blinks once and then stays on. I have tried forcing it into reset. After holding the power button about 30 seconds the power led goes off, it comes back on when I release the power button. Nothing ever happens on the screen, even after waiting for multiple hours.

I wondered if I fried my SDcard, or corrupted the image. I got a new image and tried a new SDcard. The screen doesn't change with the new image. But the power LED acts differently. Now it blinks once, comes on and then goes off in about 10-15 seconds.

This same pattern happens with the old and new battery or with just a USB cable plugged in.

Any ideas?