iOS upgrade breaks iPad USB connections
Apple’s iOS 4.2 upgrade has prevented data being read from some USB devices because the fondle slab puts out five times less power than before.
The iPad has a camera connection kit enabling pictures on SD cards in digital cameras to be transferred to the iPad. This works well with the previous iPAD O/S, iOS 3, but that has 100ma going out to the USB device whereas iOS 4.2 only dribbles out a weak 20ma, not enough for many USB-connect devices.
One contributor, Gshackman, with a Blue Yeti microphone bought from an Apple Store to work with the iPad camera connector, has the same problem; insufficient power for the mike following the iOS upgrade. He posted this point: “Come on Apple fix your mistakes, do a little testing before you turn your user base into beta testers!”
Using a powered USB hub apparently works as a fix. There has been no official communication from Apple yet
Source: The Register