Deficiencies usually result from either pre-groove or dye problems, and are a frequent cause of media failure. All six discs passed. Twenty discs failed, seventeen were marginal, and 50 discs passed. Before This important quality indicator for the unrecorded disc measures sensitivity to off-track position of the return laser beam. Radial position errors may be excessive during recording if it is low.
Problems usually point to an incorrect pre-groove.
No maximum limit exists in the standards. No discs failed, two were marginal, and ten discs passed. All six discs passed. All 87 discs passed. BLER denotes frame error rate averaged over ten seconds.