I have heard that Micropolis 1325 is prone to have a problem with a rubber
bumper that sticks to the head mechanism. Maybe it is the same for this
Micropois drive? What resolutions are there to this type of problem?
Yep, and I'm sure a lot of drives from this era have the same issue. Or
the grease in the bearings has separated out. Stuff like that. In the
inside of the HDA the oil is probably still there, just needs to re-mix
with the clay and binders that make grease grease. On the outside
bearings the oil has probably been evaporated and needs to be replaced
(new oil will mix with grease and work).
On a high performance Porsche, the exact type of grease for a wheel
bearing is critical and mixing of grease and oil is bad because it's
400+hp behind all that. A hard drive is probably a lot more forgiving
but too much oil could wash out the clay which means the oil won't stick
in the bearing.
The big problem is torque: Original coil type head assemblies had a LOT
of torque. Modern motors and the like have a lot less starting torque
because it's not normally needed. But on an old disk you don't have
enough torque to overcome the sticky pad or to mix the grease/oil and
it's stuck.
One thing I have been concerned about is if the heads have stuck to the
platter. If that happens, then turning the spindle will probably rip the
heads off. Not sure how to address this.
CZ
/Mattis
Regards
Rob
-----Original Message-----
From: cctalk <cctalk-boun...@classiccmp.org> On Behalf Of Mattis Lind
via
cctalk
Sent: 02 January 2021 08:59
To: General Discussion: On-Topic and Off-Topic Posts
<cctalk@classiccmp.org>
Subject: ICL PERQ 2 T2 Micropolis 1303 spinning down.
I have a nice ICL PERQ 2 T2 that I am going to start working with now.
First thing was to try to image the hard drive. It is a Micropolis 1303.
It spins
up but when it reaches what I think the correct speed it immediately
spins
down. Usually I think there would be a click and then the heads would
recalibrate. But there is no click and no head movement.
I really would like to make an image of the drive. What are your
thoughts?
Are the heads sticking?
Some kind of solenoid that is not releasing the heads? Not properly up to
speed? (but it sounds like the speed is right)
/Mattis
