CD/DVD Changer: Quality Check

The visual characteristics of CDs and DVDs have to be checked alongside the geometric characteristics.

Characteristic	Problem
Scratches	Light scratches disrupt audio playback (crackling). Scratches lead to gaps and jumps in the tracks. Deep scratches or holes lead to long gaps. In extreme cases, the CD is not recognized by the drive and can thus not be selected.
Recorded CDs/DVDs	Geometric characteristics do not match. Poor quality of the blank. The quality of the blank falls over its service life. UV light and high temperature damage the blank. Poor quality of the blank leads to read errors. Recorded CDs/DVDs can contain data errors.
CDs/DVDs with labels	The adhesive label can come loose from the CD/DVD due to increased temperature in the drive and damage the drive. The adhesive label changes the CD thickness or DVD thickness. This change must be checked against the geometric characteristics.