Troubleshooting iSight

Apple’s iSight cameras are high-quality web cameras that used to be external FireWire accessories, but are now built-in USB 2.0 cameras that come embedded in the top of the LCD bezels in Apple’s iMac and Macbook Pro computers.

These cameras generally “just work;” however, when they stop working (i.e., the dreaded “no camera found” error dialog, together with the camera being absent from the USB device tree in System Profiler), the cause can be both mystifying and frustrating to identify and resolve. To save you time, I’ve put together this page to help you by relating my own experiences.

Incompatible Software

The most common problem that I have had is with third-party software. Such software sometimes conflicts with Apple’s software. In particular, I have seen third-party software that interferes with the iSight camera’s ability to communicate on the internal USB 2.0 bus. You will see numerous messages of the following type in /var/log/system.log:

Dec 28 03:15:13 Serenity kernel[0]: USBF: 92838.896 AppleUSBEHCI[0x39dc000]:
:Found a transaction which hasn't moved in 5 seconds on bus 253, timing out!

There will probably be thousands of such messages in a single day’s log output.

The only way to identify the offending piece of software is by trial and error: uninstall a third-party package, reboot (to make sure no lingering instances of the software are holding any device nodes open), and test your camera (e.g., by attempting to launch PhotoBooth). You can shorten this process greatly by taking the time to remember the last thing or things you did before the camera stopped working. Did you install a new printer driver? Did you install some other piece of software (however innocuous you might think it to be)? Those are the first pieces of software you should uninstall (do it one at a time, or you won’t know which one is the culprit).

To save you some time, I’ve compiled a table of known incompatible software. If you have this software installed, then it is either the problem, or it is contributing to the problem. You must either remove it or upgrade it to a compatible version.

ApplicationVersionVendorHow to Fix
HP C3100 Series All-in-One Printer Driver 7.8.0 (version that is on the CD as of late 2006) Hewlett-Packard Uninstall the software (use the HP Uninstaller program in the Applications/Hewlett-Packard folder), then grab the updated version (7.9.1) from HP’s website.
Parallels 5.0, build 1970 Parallels The problem only occurs if you connect the iSight camera to the Parallels VM. In Windows XP, it will time out and disconnect after awhile, but if it doesn’t, then you will have to forcibly disconnect it. You will not be able to use the iSight camera from the Mac side of the world while it is connected to the Parallels VM.

Firmware Controller Has Lost Its Mind

The other major cause of problems is that the computer’s firmware controller has managed to get itself into a bad state. Remember that the firmware controller is itself running a software program to control the hardware in your computer, and software can be difficult to write; hence, it inevitably has bugs. The way out of the woods in this case is to shut down your computer, unplug EVERYTHING from it (and, in the case of Macbooks, remove the battery), and wait at least 15 seconds. Then put it all back together and turn it back on. It can’t hurt to “zap the PRAM” as long as you are doing this: hold down the command, option, P, and R keys while turning on the power, and wait until you have heard the startup sound twice, then release them. This clears nonvolatile “preferences” memory in your computer that remembers low-level startup preferences (e.g., your choice of startup device).

Sometimes, this step is necessary in addition to removing offending third-party software.

If None of This Works

Contact your authorized Apple service representative.

$Date: 2008/12/08 02:43:20 $