Calypso KOI_P clanking and whining at high frequency

Hi all,
I think here are the experts to ask, so I stop working on this disk now and ask first. I've a Calypso 200GB disk here (YAR41BW0, options KGBD) which suffered from a power supply crash in an external enclosure. I've replaced the L7250E and the -5V regulator MOSFET and verified the PCB operation on a known-working 80GB Calypso successfully (the latter also did not have a working PCB, so I decided to repair on component level). Now the 200GB drive is spinning up slowly and starts clanking, but there are no indications for a head crash, just the power accident. Anyone with experiences with this?? On-platter firmware damaged, or even the R/W amplifier in the HDA?

update: I've double checked the repaired PCB from the defective 200GB on another drives HDA - successfully again, it works just fine. Now I have encountered what I did not hear in the morning because of other noise in the workshop: a very high frequent whining which does not stop before the platters have stopped turning. I doubt that this is a bearing problem, but more likely a head torn apart or flapped over and now scratching the surface. According to Murphy, it will most likely be surface 0, now I've to talk to the customer whether proceed any further. Any comments are still welcome!

regards
shaun