Samsung Galaxy Tab 2 10.1 reset not working

A

AC Question

I had my tab for a while (three years ?) always worked great. Couple of days ago the eternal reboot loop started. I thought I would do factory reset, but the only time I had enough time to get all the way to "delete all" I pressed it and nothing happened. And it rebooted. It is rebooting every 10-30 seconds. So I tried hard reset. Pressed the power and volume up button. Instead of android logo and drop down menu, I get android dude and warning that installing custom OS might mess up the tablet. I have never tried to root the tab. If anybody has any advice, it would be greatly appreciated.