Can I use an external hard drive connected to the Photo Viewer's USB port without connecting the AC power adapter to the Photo Viewer?

• Due to the power requirements of the USB device and the Photo Viewer's display, we recommend using the AC adapter. If the AC adapter is not connected, your USB device may not be detected, or you may get an error message when you connect the device or try to transfer files. If your USB device has an AC adapter, use it to prevent the possible loss of files during transfer.