> -----Original Message----- > From: cctech <cctech-boun...@classiccmp.org> On Behalf Of Mattis Lind via > cctech > Sent: 05 January 2021 17:52 > To: David Gesswein <d...@pdp8online.com>; General Discussion: On-Topic > Posts <cct...@classiccmp.org> > Subject: Re: ICL PERQ 2 T2 Micropolis 1303 spinning down. > > Den lör 2 jan. 2021 kl 19:34 skrev David Gesswein via cctech < > cct...@classiccmp.org>: > > > This is my info on RD53 sticking heads. Your symtoms match what I have > > seen with this drive. > > > > If the heads are stuck to the rubber bumper the drive will spin back > > down when it finds the heads won't move. It will also spin down if it > > can't switch from the coarse speed control loop to using the head servo > signal. > > There is a narrow band where the heads are parked with the proper signal. > > When the rubber has deteriorated the heads are no longer over it. > > Adding shims can fix that. I used a tent with RK05 filter but others > > have opened drives in reasonably clean locations sucessfully. Best to > > keep the pets away. > > > > http://www.pdp8online.com/rd53/rd53.shtml > > > > Shim picture. > > http://www.pdp8online.com/rd53/pics/lock.shtml?small > > > > Thanks. Good advice and good prictures! Need to find some material that > makes a good shim then.
I just used a sliver of paper as a shim. It is probably not ideal, but it worked for me. > It will be very interesting if this solves the problem. > I wonder if the other symptom I saw where the drive kept spinning while the > head was moving back and forth also is related to the first? It didn't sound > like full seeks but rather quite short. The drive kept doing this for maybe > one > minute and then spun down. > > > /Mattis > > > > > > > > > > On Sat, Jan 02, 2021 at 02:05:11PM +0100, Mattis Lind wrote: > > > Den l?r 2 jan. 2021 kl 11:48 skrev Rob Jarratt < > > robert.jarr...@ntlworld.com > > > >: > > > > > > > When that has happened to MFM disks of mine it has been because > > > > for one reason or another the heads have not moved and found track > > > > 0. Why they aren't moving could be more than one reason. They > > > > could be stuck, or > > there > > > > could be some other problem that is preventing them getting the > > > > power needed to move. > > > > > > > > > > Did you solve the problem? How? > > > > > > 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? > > > > > > /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 > > > > > > > > > > > > > > > > > ------------------------------ > >