I have restarted my Mac and my iPhone. My iPhone was running iOS 9 Beta 1, and I connected to iTunes. I downgraded, and went to normal software, then it wouldn't connect to iTunes anymore. I upgraded to iOS 8.4, and that didn't work. I put it in recovery mode, and it connected; however, after the process was over, it would not connect anymore. I have literally tried everything I can think of. Please help.
iPhone won't connect to iTunes.
Reset ports yet?
Step 1
Click the Apple logo and click "Restart" to reboot your Mac laptop. A reboot is a simple way of solving common hardware problems.
Step 2
Unplug connected USB devices if the ports are still not working. Restart your computer again, and then reconnect the USB devices.
Related Reading: How to Reset Port Location on the MacBook Pro
Step 3
Click the Apple menu, select "About This Mac," and then click "More Info." Click "USB" to view a list of the USB devices connected to your Mac.
Step 4
Shut down the computer if you don't see one of your USB devices in the device list. Turn the computer back on. Hold the "Command-Option-P-R" keys together before the gray screen appears until you hear the startup sound for the second time. Release the keys.
Step 5
Press the "Command-Option-Esc" buttons to shut down applications that aren't responding.
Step 6
Click the Apple menu and click "Sleep." Wait a few seconds, and then press any key to wake the computer.
Step 7
Restart your computer. Click the Apple menu and click "Shutdown" to turn it off completely. If it isn't shutting down, hold the power button for at least 10 seconds to force it to shut down.
Step 8
Unplug the power cord, wait 15 seconds, and then reattach the cord. Wait at least five seconds, and then press the power button to turn on the Mac.
Tip
If the USB ports are still not working, your Mac maybe experiencing deeper hardware issues, so contact Apple for additional troubleshooting and possible repair.