When “CHECK DEVICE” is displayed

This message is displayed under the following conditions.

● When there is a short in the USB bus ● When an unsupported device (for example a USB mouse) is connected ● When an unsupported iPod® is connected ● When a connected iPod® is frozen ● When a transmission malfunction occurs ● When an iPod® confirmation malfunction occurs
● When a HUB class USB storage device is connected

Disconnect the USB storage device/iPod® and check it.