Sony DSX-A100U Operating Instructions Manual page 16

USB NO DEV: A USB device is not connected or
recognized.
 Make sure the USB device or USB cable is securely
connected.
USB NO MUSIC: There is no playable file.
 Connect a USB device containing playable files
(page 13).
USB NO SUPRT: The USB device is not supported.
 For details on the compatibility of your USB
device, visit the support site on the back cover.
If these solutions do not help improve the situation,
consult your nearest Sony dealer.
16
GB