-----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk- bounces at classiccmp.org] On Behalf Of Torfinn Ingolfsen Sent: 04 November 2011 22:25 To: General Discussion: On-Topic Posts Only Subject: Re: Micropolis 1355 disk drives Hi, On Fri, Nov 4, 2011 at 7:51 PM, Paul Anderson <useddec at gmail.com> wrote: Doesn't one need a clean room to fix that problem? (I've got a Micropolis 1325 which seems to have that problem) -- Regards, Torfinn Ingolfsen

-----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk- bounces at classiccmp.org] On Behalf Of Torfinn Ingolfsen Sent: 05 November 2011 12:13 To: General Discussion: On-Topic Posts Only Subject: Re: Micropolis 1355 disk drives On Sat, Nov 5, 2011 at 9:40 AM, Rob Jarratt <robert.jarratt at ntlworld.com> wrote: As in opening them up outside of a clean room?

And the drives still work afterwards?

Is there a how-to / writeup anywhere?

-- Regards, Torfinn Ingolfsen

On 11/06/2011 07:03 AM, Rob Jarratt wrote: I've done this many times, as in more than 6 and have a stack of them to be worked on yet. No clean room, however a clean space and no flying dust. I just open them up and apply power and unstick the heads while rotating. I must be rotating as the heads will slide across the disk in contact. I've had that happen with no problems I try to avoid that. If that results in the heads doing a servo seek and settling on track 000 then I needs to deal with the gummy bumper, tweezers and sine disterity to grab the bumper and remove it or place a piece of adheasive paper on it so when the head retract I do not have to repeat the process. This assumes the HDA is otherwise ok, and same for electronics. I've written this up in comp.os.. (i forget) and others have as well over the years. This works because the disk spinning has great centrifical force and anything landing is destined for the perimeter where there is a circulation filter to pick it up. This is why the drive spins up before loading the heads (also to have the needed airflow for the heads to fly.). Also whats the worse that can happen, you kill an otherwise unusable disk? Allison

I've done this many times, as in more than 6 and have a stack of them to be worked on yet.

No clean room, however a clean space and no flying dust. ? ?I just open them up and apply power and unstick the heads while rotating. I must be rotating as the heads will slide across the disk in contact. ?I've had that happen with no problems I try to avoid that.

?If that results in the heads doing a servo seek and settling on track 000 then I needs to deal with the gummy bumper, tweezers and sine disterity to grab the bumper and remove it or place a piece of adheasive paper on it so when the head retract I do not have to repeat the process.

This assumes the HDA is otherwise ok, and same for electronics.

I've written this up in comp.os.. (i forget) and others have as well over the years.

This works because the disk spinning has great centrifical force and anything landing is destined for the perimeter where there is a circulation filter to pick it up. ?This is why the drive spins up before loading the heads (also to have the needed airflow for the heads to fly.).

Also whats the worse that can happen, you kill an otherwise unusable disk?

I just move the head assembly a bit, there is an interlock mechanism that stops the heads going across the disks, but there is a bit of play in it usually which should allow you to unstick them. However, that usually is not enough to cure the problem because the bumpers have turned to sticky goo and the next time the heads touch the goo they will stick again.

I just use a Post-It, really anything will do, you just need to cut a narrow enough strip to go into the gap where the bumper is. One thing to be aware of is that the disk can be sensitive to the thickness of the paper. If you completely remove the goo you need to experiment with multiple layers of paper until the starting position of the heads is just right, otherwise you will end up with the same stop-start behaviour.