15 Nov
2006
15 Nov
'06
7:55 p.m.
Josh Dersch wrote:
As I recall, that was the behavior mine had too... slightly tweaking
that bumper
solved it....
Bet if I dig it out of storage, it still works... other than the issue
(most likely
due to the materials aging), that drive was pretty 'bullet proof'...
-- Curt
Josh Dersch
wrote:
I actually did something similar with my RD53. When I got the
machine, the drive was dead -- it'd spin up, do nothing for ~30
seconds and then spin down.
I wagered that the heads were not moving, probably a stiction problem
-- since I'd nothing to lose (same as your situation) I took the cover
off, and while the drive was powered up, I gave the heads a small
nudge. This got the drive working again. I was pretty pleased with
myself :). Ran long enough to get 2.11BSD installed on it, and
everything was sunshine and lollipops until last weekend when it died
again. The RD53 drive in my 11/73 has finally gone to
silicon heaven, after
a brief resurrection. Given the reputation these drives seem to
have, I'm not too surprised. So a few nights ago I dug through my
stacks of ancient hard drives and found three possible candidates
for replacement:
RD53... Micropolis 1325 I believe. I ran one of these (I believe it
was an RD53
actually... not just a generic 1325) in a PC years ago.
It one day started not wanting to initialize... startup... think
think, chunk chunk,
spin down....
With nothing to lose, I began to experiment...
What I found was that it couldn't apparently locate track 0. If the
HDA os opened,
it has two rubber? bumpers for the extreme ends of head motion. One
for track 0
and one for last track ?
They look something like:
----
| \
|____ /
with an adjustable slide 'hole' in the middle.
What I'm guessing went wrong is that the material hardens and/or
shrinks with age.
By carefully tweaking the adjustment on this item to allow a mere few
thousands of
an inch inward... the drive started initializing fine every time.
I did not use the drive much after that, so how drive longevity would
be effected by
the introduction of contaminants into the HDA assembly I don't know
(I of course
don't have a clean room :-) ).
However, if you have a fairly clean space, and can work carefully as
such not to
stir up contaminants, you may be able to rescue your RD53.
Another problem I read of someone having a problem with an RD53 had
to do
with the brake solenoid assembly needing adjusting as the brake pad
was dragging
(it is located under the circuit board on the bottom as I recall...
no inside the HDA).
It still spins up, but it never seems to get to a "ready" condition.
Or at least, that's how it _sounds_ -- it spins up, then sounds like
it starts to spin down a tiny bit, then spins up again in rapid
succession. It will do this for as long as I leave it running, with
no head activity at all.
So I'd like to get one of the spare PC drives I have running in this
thing, but nothing's ever that simple, it seems... :)
(On an almost completely unrelated note, I've noticed that my mails
take 1-2 days to actually make it to the list. I sent out my original
mail on Sunday afternoon (11/12) and I didn't see it show up on the
list (i.e. it didn't show up in my inbox) until Tuesday morning!
Anyone else have this issue? I know I don't get delays like this
sending email elsewhere...)
Thanks,
Josh