Strange SABRE2

[AJ2008]

I am working on SABRE2 drive which gives knocking on powering. I have tried loading from LDR in Safe Mode which results in knocking, I have tried HotSwap procedure to try access SA with no success - HDD begins knocking again. Finally I decide heads are damaged and try Head Replacement, but symptoms are the same and my donor with patient head stack is working perfectly.

Could there be some damage to the media surface while heads remain undammaged? Or am I missing something here?

Thanks

[N.C.]

If the data is still on the platters, i can help you, but not remotely.
I can do it on any case, except missing servo marks or overwritten data.

Janos