I was going to suggest pry damage at the battery connector. I work a lot on the iPad mini and I've seen what I call "fingernail damage" at the battery connector a few times. On the mini, one of the local capacitors near the battery connector is required for the 'gas gauge' function of the iPad. If it is knocked off, the iPad will actually charge okay and discharge okay, but the battery percentage will never change---it is just frozen at the same value before the damage occured. You can get into a boot loop (like you're describing here) when the actual battery percentage is too low to support keeping the iPad powered on, but the iPad doesn't "know" that the battery is low. No logic is engaged to prompt the user to charge, no low battery icon etc. If you charge the battery up some, then the auto boot problem disappears, but the battery percentage does not change.
-
All of this is fixed by simply replacing the missing capacitor on the mini, and voila, back to normal.
+
All of this is fixed by simply replacing the missing filter on the mini, and voila, back to normal.
The iPhone 5 may have a similar problem with pry damage at battery connector. In addition, the iPhone 5 has a usb charging ic near the A6 chip that acts as a charging system 'fuse' and can be damaged which will cause the phone to report that it is charging when it is not.
I try not to be too spammy on these threads, but if you're having trouble finding someone local to help you with a board-level repair, feel free to drop me an email via my profile.
I was going to suggest pry damage at the battery connector. I work a lot on the iPad mini and I've seen what I call "fingernail damage" at the battery connector a few times. On the mini, one of the local capacitors near the battery connector is required for the 'gas gauge' function of the iPad. If it is knocked off, the iPad will actually charge okay and discharge okay, but the battery percentage will never change---it is just frozen at the same value before the damage occured. You can get into a boot loop (like you're describing here) when the actual battery percentage is too low to support keeping the iPad powered on, but the iPad doesn't "know" that the battery is low. No logic is engaged to prompt the user to charge, no low battery icon etc. If you charge the battery up some, then the auto boot problem disappears, but the battery percentage does not change.
All of this is fixed by simply replacing the missing capacitor on the mini, and voila, back to normal.
The iPhone 5 may have a similar problem with pry damage at battery connector. In addition, the iPhone 5 has a usb charging ic near the A6 chip that acts as a charging system 'fuse' and can be damaged which will cause the phone to report that it is charging when it is not.
I try not to be too spammy on these threads, but if you're having trouble finding someone local to help you with a board-level repair, feel free to drop me an email via my profile.
jessa