http://forum.hddguru.com/viewtopic.php?f=1&t=29500&p=220025#p220025

I have similar problem, like in link above...

WD My Passport Ultra 2TB,
HDD model inside WD20NMW-11AV3S2 and
PCB 2060-771961-001 REV A

One day it stopped working, no clicking noises, it spins starts moving head and after some time it stops spinning and starts again immediately again to spin... I suspected that it was head problem... So I ordered same disk, same specs and disassembled. Replaced heads and I got same problem on broken hard disk, and on new disk with old head I had no problems. It worked OK... After that I asked my friend to replace two BIOS IC, since I thought it is PCB problem... But after replacing BIOS IC's old disk was in slow mode as biggerpizza said. I could see size of disk and type of disk, but could not access disk files. So we decided to return BIOC IC's as they were originally. But then I have same problem and with the new disk, it is in slow read mode, and old one has same problems, stops spinning after some time. Interesting is that if I swap motherboards both of disks are spinning, I can hear head that is trying to read but never initializes... I don't see disk, I can see only My Passport 0820.

What to do now? Can you help me? Pleaseeeee

I will buy some beer to one who help me

You need the free assistance of user fzabkar - memberlist.php?mode=viewprofile&u=13702

_________________
Luke
Recovery Force Data Recovery

Now it's time to realize you destroyed the drive along with any hopes of recovery, throw it in the trash, and move on. Should have never opened it.

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Data Medics - Hard Drive, SSD, and RAID Data Recovery Service Company

Can you at least explain what I did wrong? Both of the disks with swapped heads worked as with their original heads, new one worked as before, old one same symptoms? Problems began when I swapped PCB Bios IC's...

I didn't say that data on this disk is not so important, is not worth of paying few hundred dollars for recovery, so I decided to play and learn. I did Head swap in pro clean room with no dust and other contaminant...