USB 1.1: FAQ (4 of 4)

Questions answered in this article:

1. Where can I find out about USB products available from third-party developers?
2. What kinds of error messages regarding USB devices might I see? What can I do about them?

Question 1: Where can I find out about USB Products available from Third-Party developers?

Answer: At the following addresses, among others:

• http://www.macsoftware.apple.com
• http://www.apple.com/usb
• http://guide.apple.com

As you shop for USB devices, you're likely to find many that will work with the Mac OS. If you want to find devices that have been specifically tested for compatibility with Mac OS, look for products that have both a USB logo and the Mac OS logo. If a USB product you're interested in has the USB logo only, check with the vendor manufacturing the product and ask about Mac OS compatibility before making your purchase.

Question 2: What kinds of error messages regarding USB devices might I see? What can I do about them?

Answer: If you encounter any difficulties with USB devices, they will be easily resolved. There are three kinds of error messages or dialog boxes Mac OS may use to alert you to a USB issue. These include:

• Not Enough Power to Function
• Not Enough Power for All Functions
• No Driver Found

Not Enough Power to Function

Mac OS will generate a Not Enough Power to Function message if:

• a device attempts to draw too much power from the USB bus.
• one or more devices plugged into a hub requires more power than is available.
• you've attached a self-powered device (like a printer or floppy drive) and forgot to plug it into an electrical outlet.

What to do? If you're using a self-powered device, check to see if the device is plugged into an electrical outlet. If not, try connecting the device directly to your iMac or to a port on a self-powered hub. If you're connecting the USB device to a self-powered hub, make sure the hub is plugged into an electrical outlet.

Not Enough Power For All Functions

Mac OS will generate a Not Enough Power for All Functions message if there is enough power to supply some but not all of the functionality the device is designed to provide.

What to do? As above, see if the USB device has its own power cord and, if it does, plug it into an electrical outlet. Otherwise, try plugging the cable for the USB device directly into to your iMac or to an available port on a self-powered hub. If you're connecting the USB device to a self-powered hub, make sure the hub is plugged into an electrical outlet.

No Driver Found

Mac OS will generate a No Driver Found message if a driver for the USB device you just connected cannot be found in the System Folder. If you get this message, you may have forgotten to install the software that came with the device, or you may have put the device driver (that is, the software that allows iMac to recognize and communicate with the USB device) in the wrong place in your System Folder.

What to do? Reinstall the software driver from the CD-ROM that came with the product, or download and install the driver from the product vendor's Web or FTP site on the Internet.

For more information on USB troubleshooting, refer to the following articles:

• Article 43023: "USB: Troubleshooting Error Messages"
• Article 58033: "USB: Device Troubleshooting"

Other USB FAQ's can be found in the following articles:

• Article 30650: "USB 1.1 FAQ (1 of 4)"
• Article 30651: "USB 1.1 FAQ (2 of 4)"
• Article 30652: "USB 1.1 FAQ (3 of 4)"