iPhone: Troubleshooting USB connections
Symptoms
When attempting to sync, update, or restore the iPhone, you may receive one or more of the following symptoms:
- An alert message indicates an unknown error occurred
- The iPhone unexpectedly disconnects during a sync or restore
- Photos downloaded from the iPhone appear garbled or not all photos transfer
- An alert message indicates the USB device cannot operate because it needs more power than is available
- An alert message indicates "this device can perform faster" if you plug the device into a higher speed USB port
Products Affected
iPhone, iPhone 3G
Resolution
For best results, use a USB 2.0 connection with iPhone. Check Apple System Profiler or Windows Device Manager to see if a high-speed USB 2.0 connection is available on your computer.
Use the following suggestions when troubleshooting the connection between your iPhone and the computer.
- Avoid plugging the iPhone into a keyboard, display, or standalone hub which only offers USB 1.x or which has a USB 1.x device connected to the same hub.
- Try plugging the iPhone directly into a USB 2.0 port on the computer.
- Try plugging the iPhone directly into the USB to Dock Connector cable without using an iPhone dock or other dock or adapter.
- Try another USB to Dock Connector cable if available.
- Try shutting down and then restarting the computer.
- If the issue persists and you are using a Mac, try resetting the USB connection by following the steps in this document.
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