Toshiba DT01ACA050 (Hitachi 7210DLE6) Role of "B" Imp mods

[terminator2]

I have got a Toshiba DT01ACA050 3.5" SATA hard disk. It is accessible through Hitachi utility Model 7210DLE6 Single Head disk.
Some "B" Imp. modules have errors. Disk is not giving smooth sectors access and giving lots of bad sectors and sometimes becomes non -ready.
I want to know role of following modules for this behavior
AMPM Factory Tests logs module
HLR1 & HLR2 Factory Tests logs module

Attachments

[chipsang]

These modules are not causing bad sectors. This is single head hard disk. Heads might have become weak or surface has bad sectors.