here i attach the picture for sediv C H S scan.
1. scan SA bad sector on every head, and give you a static chart about defect and info about defect, and you directly add it to SA list. after that translator regeneration is required.
2. test every zone of user are on every head, this is used to find damaged zone,
3. option to select read and write tests.
4. scan user area and add defect into p list, (WD hdd).
some time when self scan of SA find that there are many bad sector in SA and it add into SA list, some time this is not real and you cut head, in this situation you need C H S scan function.

Regards
Waqas Ali

Correnction for point 2.

test every zone of user area on every head, this is used to find damaged zone,