Sony CD Walkman D-NF430 Operating Instructions Manual page 36

Symptom
The LCD display becomes hard to
see or slows down.
Even though you have not selected
"BOOKMARK,"
flashes.
Play stopped abruptly.
The TIMER function is canceled.
Radio
Symptom
The radio is weak or has poor
quality.
Others
Symptom
When closing the lid of the CD
player, the CD starts to rotate.
You cannot operate the CD player
properly using the remote.
1) D-NF430 USA, Canadian, JED models and D-NF431 models.
36
Cause and/or corrective action
 You are using your CD player at high temperatures (above
40°C/104°F) or at low temperatures (below 0°C/32°F). At
room temperature, the display will return to its normal
operating condition.
 If you have selected a playback option other than
(Bookmark)
"BOOKMARK,"
 The off timer has been set. Change the setting of "TIMER" to
"OFF" (  page 27).
 The dry battery is used up completely. Replace the dry battery
with a new LR6 (size AA) alkaline battery (  page 12).
 The TIMER function for the CD is canceled if you start
listening to the radio.
 The TIMER function for the radio is canceled if you start
playing a CD.
Cause and/or corrective action
 Replace the battery with a new LR6 (size AA) alkaline battery
(  page 12).
 Move the CD player away from electric appliances (TVs, PCs,
etc.)
 Keep the AC power adaptor away from the CD player.
Cause and/or corrective action
 The player is reading the information on the CD, not
malfunctioning.
 The buttons on the player are kept pressed by mistake.
1)
 The remote is not connected securely.
(Bookmark) flashes.