NAD C 520 Manuel D'installation page 7

amount of a mild kitchen detergent added, and then
wiped dry with a clean, soft towel.
When cleaning the disc, use only RADIAL strokes
(from center to edge). Never use a circular wiping
motion like that used for cleaning ordinary LP
records, because in wiping the disc there is a risk of
scratching it. A radial scratch will do the least harm
because it affects only a small portion of each circular
data track, which can be fully compensated by the
player's error-correction circuits. But a circular
scratch that follows a data track may damage such a
long continuous segment of data that it cannot be
corrected.
ABOUT THE LASER
The Compact Disc player uses a solid-state semi-
conductor diode laser, mounted on a tracking servo
mechanism, to play the disc. The laser illuminates the
track of microscopic pits representing the digital data
TROUBLESHOOTING
SYMPTOM
No Power when the POWER
button is set to ON
Disc play does not start
No sound
Sound skips
Remote control does not work
A "humming sound can be heard
bits, while photo-diodes detect the reflected illumina-
tion from the disc and convert it into an electronic sig-
nal which is then decoded to recover the musical
waveform in each stereo channel.
You cannot see the laser operating, because it
operates at wavelength of 7800 Angstroms, which is
in the infrared and thus invisible to the human eye.
The Compact Disc player is completely safe for
children to use. The laser operates at very low power
and is concealed within the player mechanism. Even
when the player is disassembled, the laser remains
sealed within an optical system that causes its light to
focus only 1 millimeter from the lens and then diverge
rapidly, reducing its intensity to negligible levels.
POSSIBLE CAUSE
Poor or no power plug connection at the AC outlet. Insert the power plug
firmly into the AC outlet.
The disc is loaded upside down. Reload the disc with the label side UP.
The disc is too dirty. Clean the disc.
Incorrect audio cable connections. Connect the CD player to the
amplifier/receiver correctly.
Incorrect amplifier/receiver operation. Make sure that the input selector
on your amplifier or receiver is set to CD.
The CD player is subject to vibration or physical shock from external
sources. Change the installation location.
Batteries in Remote Control handset have expired. Replace batteries.
Object obscuring remote sensor on the player. Remove any objects
directly in front of the player.
Loose cable connections. Check the cable connections, particularly the
phono connecting cables.
GB
NAD
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