Chevrolet Optra 2005 Owner's Manual page 159

If playing a CD-R the sound quality may be reduced
due to CD-R quality, the method of recording, the quality
of the music that has been recorded, and the way the
CD-R has been handled. There may be an increase
in skipping, difficulty in finding tracks, and/or difficulty in
loading and ejecting. If these problems occur try a
known good CD.
Do not add paper labels to CDs, they could get caught
in the CD player.
If an error appears on the display, see "CD Messages"
later in this section.
All of the CD functions work the same while playing an
MP3, except for those listed here. See "Playing a
CD" earlier for more information.
5 DN (Down): Press this pushbutton to go to the
previous directory.
6 UP: Press this pushbutton to go to the next directory.
TRACK (Previous/Next File): Turn this knob
one notch to go to the first track in the previous or to go
to the next folder. The player will continue moving
backward or forward through the CD with each turn of
the knob.
DIR (Directory): Press and release this button to
repeat the tracks in the current directory. DIR will appear
on the display.
Press and release this button twice to repeat the tracks
in all of the directories. ALL will appear on the display.
Press and release this button again to turn off
repeat play.
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