Reported symptom: laptop was in use and froze. At the same time client heard clicking from hard drive area.

Has original PCB, ROM, NVRAM, etc. S/N in ROM and NVRAM matches label S/N.

Drive comes ready and displays log in pic below. Though I can hear a quick soft click during init, I did not experience any loud clicking that client reported. This click has persisted after all diagnostic steps.



Here are the steps I've taken so far that have produced no change in symtpoms:

-Sliders are clean, tried new heads.
-Patient heads work in 2 donors.
-Tried patient ROM on donor PCB (via programming).
-Tried donor PCB (physically moved ROM).
-Tried patient ROM (patched with donor NVRAM) on donor--donor initializes.
-Tried donor NVRAM patched with all patient adaptives (5 or 6 sections of unique code).
-Tried patient NVRAM (patched with donor adaptives) on donor--donor initializes.
-Swapped magnets, donor initializes with patient magnets.
-No platter wobble.
-Edited head map in ROM to start with H1.
-Extra copy of NVRAM in ROM is identical to main copy.

Though NVRAM has several unique sections, through analysis with a few testers (of only this model) I've found that the 4 highlighted bytes are all that need to move with the drive in order for it to initialize.



With that in mind, I've patched patient NVRAM with only these 4 bytes from donor NVRAM, and donor initializes with full capacity and sector access (though probably limited).

All I can speculate at this point is that the mentioned 4 bytes in NVRAM are the actual pointers to the directory module and this somehow became corrupted, or the pointer is ok and USAG is corrupt in some way. Not sure how to proceed at this point--would appreciate any ideas.

so problem is not with heads , service has problem, have you tried LDR ?

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Data Recovery Pakistan

I really overthought this case. Thanks for the suggestion--I'm making some progress now.