Re: Platinum 5.25" drive problem

["Brian K. Lambert" <lambert@ERC.MsState.Edu>]

> John L <jd@logotech.i8.com> wrote in message
> pgpijtguab39snlofp93kkd7afuiu9ffb4@4ax.com">news:pgpijtguab39snlofp93kkd7afuiu9ffb4@4ax.com...
> > One of my Platinum 5.25" drives can no longer boot or read/write any
> > 5.25" disks.  I have tried cleaning the drive heads to no avail and
> > also adjusted the drive speed.  I noticed that when I attempted to
> > adjust the drive speed using Copy II Plus 8.2, the stated speed
> > appeared to jump erratically from 0ms up to 300ms and never settled
> > within the normal 198 - 202ms range.


I have an American Micro Research 5.25" drive which was doing something
similar, w/ respect to the speed jumping erratically.  I took the cover
off the drive... turns out it was caused by the disk itself periodically
slipping from the grasp of the drive motor.  This was really hard to see
at first, you have to watch it closely.

I can get it to work by placing pressure on the lever which you close
after inserting the disk, thereby increasing the friction between the
drive mechanism and the disk.

I thought it was because the inner ring of the disk was worn out, but the
same thing happens with relatively new disks.

Has anyone else seen had this experience?  Any suggestions for safely
improving the grasp that the mechanism has on the disk?


--Brian