Aura H2O 2 Stuck On Sleeping Screen SE Blank MEGREZ

[neocremia]

Hi guys! I had an used Kobo Aura H2O Edition 2 last week. I was using device with no problem until this morning. I bought a cover for my device with "Auto Sleep" option and this morning I tried to turn on my device. It was stuck in "Sleeping" screen with my last read book's cover. It was not responding to power button. When I get home, tried to connect to my Windows PC. But now it looks like "SE Blank MEGREZ" in my pc's screen and I can't get in to my device. I am sure about that my battery isn't empty and my device's screen doesn't look like it is charging. In forum I saw some other people experienced that issue (SE Blank MEGREZ) with other devices (like kindle). Can you help me about that? (Sorry for my english, it is not my native language)