RX02 / DSD440 problem

From: Tom Leffingwell <tom_at_sba.miami.edu>
Date: Wed Feb 27 09:48:10 2002

On Wed, 27 Feb 2002, Pete Turnbull wrote:

> That's the head positioner leadscrew. On powerup or a Bus Init, it should
> move back to track zero (maybe only if there's a disk in ithe drive,
> depending on the controller). The drive belt is on the underside of the
> drive. They often fall off.

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.

> A quick way to test if the drive is turning, is to take a floppy, trun the
> disk in the jacket until the sector hole is visible in the round hoe in the
> jacket, put it in the drive, close the door, open the door, take the disk
> out, and see if the sector hole is still visible. Most 8" drives rotate
> all the time, so closing the door (which clamps the disk to the spindle)
> should turn it. The odds of the sector hole ending up in exactly the same
> place after this are minimal. It doesn't tell you if the drive is running
> at the correct speed, but it will tell you if it's not turning at all.

I could easily see the disk turning with the cover off of the unit. I
guess I can't verify the speed, but I don't think that's the problem,
because I can't even get far enough to attempt to read something. When
the unit powers up, it detects the problem when it tries to move to track
0 (with or without a disk), and then then LED on the front just flashes,
at which point it won't do anything unless you power cycle it.

There are several LEDs inside the case that light up. Does anyone have
docs for this thing that might be able to look them up?
 
> If not, the most common causes are that the drive belt has slipped off the
> pulley, or that the plastic collet which clamps the disk has broken and
> isn't clamping, or not well enough.
>
> --
> Pete Peter Turnbull
> Network Manager
> University of York
>
Received on Wed Feb 27 2002 - 09:48:10 GMT