When heads meet scratches

[Jirbun]

Hi
I wonder what exactly bothers the heads to go over platters scratches is it the preamp ? mechanical limitations ? and it's true if we disable specific head then it can go over severe scratches and survive like this guy claims ?
https://www.youtube.com/watch?v=n1OcTKDjO2g

Thanks

 

[LarrySabo]

I believe that video is a fraud. Going over that scratch would have ripped the heads off or at the very least, damaged them severely. There is going to be platter dust everywhere throughout the drive as a result of that scratch, destroying all the heads and contaminating all the platters. At the very least, he would have had to thoroughly clean all the platters, physically remove the top head from a compatible donor head stack, image from all platters except the top one, replace the head stack again but with one whose top head is still attached, limit travel of the heads to the edge of the good portion of the top platter, and image the readable portion of the top platter to combine it with what was already imaged. I believe it's possible to do but by very few highly advanced data recovery techs.

DTI Data Recovery are the folks who sell the Base Replace tool, so they may be capable of doing it.

 

[lcoughey]

This video is quite old and I've done it hundreds of times. The drive will degrade fairly quickly with the top head floating over that scratch, but it is possible to image most, if not all of the other surfaces before that happens.

 

[Jirbun]

And what tool is good for cutting physically middle heads smoothly ?

 

[LarrySabo]

See this thread: st2000vm003-headmap-t1864.html#p8880

 

[Blizzard]

See this thread: st2000vm003-headmap-t1864.html#p8880

Those snips Sam recommended work well.