Sony Walkman NW-HD1 Operating Instructions Manual page 38

Sound
Symptom
There is no sound. Noise is heard.
The volume does not increase.
There is no sound from the right
channel of the headphones.
The volume cannot be adjusted.
When using the player with a
stereo system connected, the
sound is distorted or noisy.
38
Case and/or corrective action
 The volume level is set to zero. Turn the volume up
(  page 18).
 The headphone plug is not connected properly. Connect it to
 (headphones)/LINE OUT jack securely (  page 18).
 The headphone plug is dirty. Clean the headphone plug with a
soft dry cloth.
 No audio data is stored in the hard disk.
 "AVLS" is set to "On." Set it to "Off" (  page 28).
 The headphone plug is not connected properly. Connect it to
 (headphones)/LINE OUT jack securely (  page 18).
 "Audio Out" is set to "Line Out." Adjust the volume using the
volume control on the connected device, or set "Audio Out" to
"Headphone" (  page 28).
 "Audio Out" is set to "Headphone." Set it to "Line Out" ( 
page 28).