I had this same boot loop issue happening numerous times with my Lenovo Tab 2 A7-10 (brought in France in August 2015), even few months after buying it. At first I tried to disconnect/reconnect the battery but this method never worked. It seems the external SD card is the culprit (it seems to pump the amount of energy it need to properly boot) Here is the working method I use each time : 1. Remove the SD card 2. Connect the USB to charger 3. Normally, the tablet will vibrate, then show Lenovo logo, then show the battery level. 4. Wait till battery is charged at least at 5% 5. Power on the tablet. Hope this will help. The main issue is that the tablet is vibrating and starting when the USB connector is plugged, which is a bad design as this drains more battery power than the USB power can load the battery during the same time. It should be able to just refuel when connecting the USB cable, without powering it up.