Hi:
I have an BH16NS40 1.0 drive and suddenly its starting failing in burning BR drives.  I am using Verbatim BR disk CMCMAG-BA5-000 disk and it burned correctly plenty of them. But, now, when I burn at 4x speed sometimes it finish the disk and did not burn nothing, remains empty,  others times burn but the disk is no readable at the end. If I try a 6x speed it says that can not make the Power Calibration. 
Is this a disk problem or is this a BlueRay device problem?  Should I inspect some logs? Should I think I buying a new one? Any test that I came make?
With my best regards and thanks for your help and guidance