Common Maxtor MFM drive failure mode -- any ideas?

[Josh Dersch]

On Fri, Oct 23, 2015 at 9:08 AM, Al Kossow <aek at bitsavers.org> wrote:

> On 10/23/15 12:04 AM, Josh Dersch wrote:
>
> The 2190 does not, and it fails in precisely the same way I've personally
>> seen three or four other Maxtor drives of the same era fail: It spins up
>> fine, but when it goes to load the heads, it sounds
>> like the voice coil positioner for the heads is "screaming" -- it emits a
>> high-pitched, quite loud whine/buzz which persists until you power the
>> drive down.  The drive is unresponsive during this time.
>>
>>
> Sounds like a failure of the positioner servo. It is on a separate platter.
>
> It should be possible to build something to open the servo loop and
> position the heads
> externally. One of those projects that I would like to get to some day. I
> have about 50
> Maxtor ESDI drives from Apollo's build system that I REALLY want to get
> the data off of
> and I suspect there will be the same sort of problem with them.
>
>
Hm.  It would be interesting to test the servo failure hypothesis; I don't
suppose anyone has a service manual for these things so I know what stuff
to probe?  (Nothing on Bitsavers and a casual Google search turns up
nothing of interest.)

- Josh