A couple of months ago, my iPod Touch began to intermittently drop its connection to my PC during synchronization. The iTunes synchronization progress bar would stop moving and, after a minute or so, iTunes would report that the device was disconnected. Usually, the iPod would be unable connect again until after I rebooted the PC.
Since the iPod would sync without problems to my notebook, and since the PC was running the Windows 7 64-bit RC, I figured the problem was just a bug in the pre-release software and would be fixed in time by a new driver or the final version of Windows 7.
When I added a new iPhone 3GS to the family, I wasn’t surprised to see the same problem occurring with it. It was definitely being caused by something at the PC end.
However, a couple of weeks ago things got much worse. After a dropped connection during synchronization one morning, and the customary PC reboot, neither my iPhone or iPod would connect at all. After plugging the USB cable in, the iPhone or iPod would continually flash the synchronization screen on and off, with the plaintively making the “USB connection” beep until I took pity and pulled the USB plug.
I figured that the device driver had somehow been corrupted and, since it is difficult to uninstall a USB driver when the device isn’t connected, I tried plugging the iPhone into a USB port on the back of the PC. That connection lasted about 30 seconds before dropping again, and would thereafter result in the same connect/disconnect cycle as the front USB port.
Though I didn’t realize it at the time, the fact that the behaviour was somewhat different on a 2nd USB port was a clue to what was wrong.
I tried the usual common sense approaches to resolving an iPhone or iPod synchronization problem:
- Uninstalled the iPhone and iPod drivers from the Device Manager. (For instructions on how to do this for a USB device you can no longer connect, see this article on the excellent How-To Geek site).
- Uninstalled iTunes. (In all versions of Windows you can get to the uninstall program by running a Control Panel applet. On Windows XP it’s “Add or Remove Programs” — in Windows 7, the applet is named just “Programs”.)
- Uninstalled “Apple Mobile Device Support”, from the same Control Panel applet.
- At this point I tried connecting the iPhone. This should have caused the driver to be automatically reinstalled and, hopefully, would fix the problem. The PC tried to reinstall the driver, but since the USB connection immediately dropped, all I got was an “Device driver not successfully installed error” for the “MTP USB Device”. Yikes, not a good sign.Uh oh, that can't be good!
- I reinstalled iTunes which, given the result of the previous step, predictably didn’t solve anything.
- I tried updating the PC BIOS, in case a chipset bug was at fault. A longshot, and that it didn’t solve anything.
Googling the above “MTP USB Device” didn’t uncover any iPhone-specific issues (it turns out that this “Mobile Transport Protocol” driver is used for almost any multimedia device).
Googling the broader problem of dropped iPhone connections uncovered a lot of people who had this problem with using a USB hub. Plugging their iPhone directly into a USB port on the PC fixed the problem for them, since the hub wasn’t able to provide the 5 volts of charge required by the iPhone (the iPod Touch has a similar power requirement).
In my case, I already was plugging the devices directly into the PC. But what if the PC’s USB port was not providing the 5V that it should?
I happened to have a powered USB hub – that is, a hub with a power cable. These are intended for use when connecting multiple power-hungry USB devices at the same time.
Sure enough, when connected to the same PC through a powered USB hub, both the iPhone and iPod Touch synchronized successfully. That was a week ago, and everything has been rock solid since then.
The USB hub that I’m using is an inexpensive 4-port hub from a company named Tripp-Lite — I’m pretty sure that any powered USB hub would have worked just as well. To be clear, though, the trick is to use a USB hub that has its own power cord — the more common (and less expensive) hubs are powered through the PC’s USB port, and those don’t generally work well with the iPhone and iPod Touch.
Of course, this doesn’t solve the underlying problem — why are this PC’s USB ports supplying less than 5V? The ports are provided some power — enough to satisfy a memory stick or mouse. A quick scan of the motherboard and power supply didn’t uncover any obvious problems, so I’ll have to leave that mystery to another day. Since the case (Antec 300), motherboard (Gigabyte GF8200A) and power supply (an ePower 550W unit) are all quite new and of reasonable quality, I’m guessing that I’m not the only one who might have this problem.
If you’re having problems with dropped iPhone or iPod Touch connections, give a powered USB hub a try.