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It started with 7.1.2 and it has gotten worse with ios8. Despite the ipad being fully charged overnight the screen refuses to turn on. Even when I try to do a soft reset it won't work. It finally turned on later this afternoon but after five minutes of use the device shut down and reset itself. I then did erase all content and settings and now it has shut off completely again. I've never had these problems the first few months of this ipad. Does anyone have suggestions?
First thing to try: Do a hard reset. Hold both the sleep/wake button and the Home button down until you see the Appe logo.
Next, is the device still under warranty? Even if it’s not, making an appointment with an Apple Store genius may be your best course of action.
Failing that, I would suggest that you plug it into your computer and do a full backup, if you can do that. Then, I’d put the iPad in DFU mode and restore it as new - it will download a fresh copy of iOS and install it. Then you can recover your data from the backup.
But be advised, if your issue is hardware, nothing you can do software-wise will make much difference.
To put your device in DFU mode:
Make sure that you’re running the latest version if iTunes. Then, follow these instructions:
How to put your iPhone or iPad into DFU mode | iMore