RX02 / DSD440 problem - test-drb@ccmp.vtda.org

27 Feb 2002

On Feb 27, 10:48, Tom Leffingwell wrote:

...
  It does look like it wants to go back to track zero. 
If I manually line
 it up just right, it will power up correctly, but as soon as it wants to
 go somewhere, the problem starts over.  Meanwhile, the other drive lines
 itself up just fine. 
Then it's possible that the drive to the stepper motor that turns the
leadscrew is, er, screwed.  It might only be one phase; if you can turn it
easily by hand when it's powered up, then it's probably not being driven at
all so look for a destroyed driver or lack of 12V (or is it 24V? ).  If it
tends to settle into certain positions and won't step but does sort of
vibrate and isn't very easy to turn by hand when the power is on, it's
probably just one phase; look for a blown driver transistor (if the drive
has such) or a faulty stepper driver IC.  It's also possible (though
unlikely, in my experience) that one of the coils in the motor has burnt
out.  You can check that with an ohmmeter, comparing it to the working one.

-- 
Pete						Peter Turnbull
						Network Manager
						University of York