iPad can not boot, unlimited restart when connecting the charger
This is an iPad Air 2, bought 2 years ago. The system is iOS9.x, had jailbreak, the use has been normal.
There are about half a year, I did not charge and use the iPad.
Now iPad can not boot, I try to solve it, summarized as follows:
1. Long press the power button, iPad does not respond, can not boot, guess is the power exhausted.
2. Found the iPhone 1A charger, connect iPad, iPad without any response, the screen is still black, no low battery reminders, for half an hour after still no response.
3. finally found iPad 2.1A charger, connect iPad, very lucky, iPad has a reaction. The screen is lit, you can see the Apple logo appears, after 2-3 seconds, the screen completely extinguished, and then re-lit Apple logo, repeated ... ...
4. try to connect to the Mac, iPad is no response, can not boot.
5. When I connect iPad and iPad (2.1A) charger, you can enter the DFU mode, but disconnect the charger, iPad quickly turn off the power, the screen becomes black.
Excuse me, how do I fix this problem? Very thanks.