4.2 BSD Installation problem

[sechrest]

We have sometimes had similar problems on our RA81`s. I have no
specific understanding of what is going on, but it seems that we 
can eliminate some class of disc errors by replacing the spindle 
brushes and insuring good clean contacts on the ground wires.

There was a suggestion on the net a long time ago that it was a static
build up on the spindle. Dec has said that this should not happen, but
they come in and change the brushes when I ask them.

The normal sequence of failures starts out with a couple of errors and
then it slowly builds up to many errors. The HDR errors are generally not
the same. Ie they seem to move around the disc. If they get too bad
the disc will get some serious trash on it, but we fix the problem before 
that.

					John Sechrest
					sechrest at orstcs