Several users have reported an issue in which iPads generate the error message “Cannot Use Device. The connected USB device requires too much power” when previously working USB devices are connected via the Dock after the update to iOS 4.2.1. This issue may occur with SanDisk CF readers, cameras connected via the camera connection kit,
Fix: Use and externally powered USB hub
Unfortunately, the only viable fix for this issue thus far is the use of an externally powered USB hub. Battery-powered models can be had for roughly $20.
You can also downgrade to iOS 3.2.2, which will restore the old, higher power limitation, though you will lose all of iOS 4.2.1’s benefits.
Obsessed with tech since the early arrival of A/UX on Apple, Sudz (SK) is responsible for the editorial direction of AppleToolBox. He is based out of Los Angeles, CA.
Sudz specializes in covering all things macOS, having reviewed dozens of OS X and macOS developments over the years.
In a former life, Sudz worked helping Fortune 100 companies with their technology and business transformation aspirations.