Does your iPad or iPhone keep on rebooting? Does your log show CRC ERR? CRC means Cyclic Redundancy Check.

Here's what I did to fix mine.

1. Connect the unit to a laptop and open iTunes app.
2. Back-up your files first. By clicking on iPhone then Back Up Now button.
3. Check if iTunes is of its latest version. Click on iTunes then Check for Updates. Make sure to update to the latest version.
4. Set unit to DFU mode. You will enter DFU mode by pressing power button and home button at the same time for 10 seconds. Continue to press the home button but unhold the power button until a message will appear in your iTunes app. It will ask you to restore your unit to its latest OS.
5. Click Restore button. iTunes will download the software and automatically update your unit. Don't unplug until done.
6. It will ask you to setup your unit again. Make sure to Restore from your previous backup (from step 2).