RD54 Stopped Spinning

[Robert Jarratt]

> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Holm
Tiffe
> Sent: 04 April 2015 10:00
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: RD54 Stopped Spinning
> 
> Robert Jarratt wrote:
> 
> >
> >
> > > -----Original Message-----
> > > From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of
> > > Eric Smith
> > > Sent: 04 April 2015 04:01
> > > To: General Discussion: On-Topic and Off-Topic Posts
> > > Subject: Re: RD54 Stopped Spinning
> > >
> > > On Fri, Apr 3, 2015 at 11:44 AM, tony duell
> > > <ard at p850ug1.demon.co.uk>
> > > wrote:
> > > > The RD54 is a Maxtor XT1140 or something similar.
> > >
> > > The RD54 is a Maxtor XT2190, which, as you say, is quite similar to
the
> XT1140.
> > > Both have 15 data heads (eight platters), but the XT2190 has a
> > > higher cylinder count (1224 vs 918), reportedly at least in part due
> > > to use of a better head design.
> > >
> > > Maxtor pioneered the use of the drive motor integrated in the
> > > spindle, which is what allowed them to fit eight platters into a 5
> > > 1/4" drive in 1983, when other vendors were limited to four platters.
> >
> > Hmm... does that mean it might be difficult to reach/see/replace the
hall
> effect sensors?
> >
> > Regards
> >
> > Rob
> 
> Difficult? Hmm.. I would say they are some of the last things you see if
you
> dismount the entire drive including the stack of platters.

This is what is worrying me. I suspect this would be a very difficult
repair. I have enough bad RD54s that I suppose I could sacrifice one to work
out how to do it (if at all!).

> 
> This is not the way to repair the drive.
> Try to find out if the Motor Coils are ok and connect a scope to the
phases to
> see what's going on after power up.


Is there a good resource on the theory so I can work out how it all works
and what to expect when I use a scope? Wikipedia has some stuff, but it is
all a bit theoretical.

> I've repaired several old disks with different failures and opended them
at
> home, but this isn't really what you want and you should avoid doning this
if
> possible. Some people say doing this in the kitchen a boiling put of water
> nearby is the best you can do to avoid dust ..


Nice idea, one to try!

Thanks

Rob