salam alekm hello
i was repairing hdd wd 1000ab i note that in head map there is 6 heads from 0 to 5 and head 0 is only one is disabled this means that sa at head 1 any way i made bad action by activate head 0 the hdd start knocking then worked again but as wd 1200ab and with no sa as here head 0 is the first one i tried to undo but no way its knoking when i disable head 0 so i think i must have fw for wd 1200 ab to solve this prob

set 3 jumpers and start in kernel mode, set previous head map ant check if its still knocking

salam alekm hello

i did this but it seems somthing changed in sa and now it dosent wont back to original condition as 100 gb hdd it just accept to be 120 gb

After head map u have to set the capacity again , did u do that .