Disc Interchanging - HP 9121D/S User Manual

HP
9121/22 D/S
[2] Disc Interchanging
It is possible for a drive to pass all READ/WRITE tests, yet fail
when reading a disc which has been initialized or written on by
another drive. This type of failure can be caused by misalignment
of the drive mechanism or of the PLL frequency.
To determine which drive is misaligned, test with a disc that has
been initialized and written on by a known-good drive.
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