Sony HAP-S1 User Manual page 123

The HDD AUDIO PLAYER is compatible with the ext4 and FAT file systems. If the external
hard disk drive has a different file system, format it using the Format External HDD function
of the HDD AUDIO PLAYER. If you cannot format it, check the following:
Check that the USB cable used to connect the external hard disk drive is connected firmly and is not
damaged. The connection may also become unstable depending on the type of USB cable being
used. In this case, try another USB cable.
Turn off the HDD AUDIO PLAYER and then remove the external hard disk drive. Connect the external
hard disk drive again and then turn on the HDD AUDIO PLAYER.
If the external hard disk drive is used with bus power, the connection may be unstable. In this case,
use the external hard disk drive with an external power supply.
Some music files are not transferred.
Transfer of music files may be cancelled because the hard disk drive you specified is full.
The audio file format may not be compatible with the HDD AUDIO PLAYER. Music files that
have file extensions not supported by HAP Music Transfer or the HDD Audio Remote
application installed on your smartphone or tablet cannot be transferred to the HDD AUDIO
PLAYER.
The read attributes of some files or folders may be not permitted.
An external hard disk drive that has been used with the
HDD AUDIO PLAYER cannot be used with your computer.
The external hard disk drive that has been formatted by the HDD AUDIO PLAYER cannot be
recognized by the computer.
If you want to use the external hard disk drive with your computer, format it on the computer.
Please note that if you format the external hard disk drive with your computer, all stored
music files will be erased.
You want to delete music files but do not know how.